# Car advertised with 650hp and warranty (me thinks not)



## Alan (Jul 1, 2001)

Copied from the advert :nervous:

"THE UK CAR HAS BEEN PROFESSIONALLY RE MAPPED TO 650BHP AND HAS TO BE ONE OF THE FASTEST NISSAN'S AVAILABLE TODAY. ALSO COMES WITH THE BENEFIT OF A NISSAN MANUFACTURES WARRANTY UNTIL JUNE 2012."

ALEXANDERS PRESTIGE : NISSAN GT-R 3.8 BLACK EDITION AUTO 650BHP


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## Kamae (Jun 15, 2009)

What do you have to do to a GTR to get 650 bhp!?
I've heard of access ports, remaps and exhaust mods, but this must go quite a way beyond that if it really is 650bhp.

Maybe the claimed power is just as unbelievable as the claimed warranty!!


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## Jm-Imports (Feb 12, 2007)

still has stock exhuast it will be nowhere near 650


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## R33_GTS-t (Apr 27, 2005)

Uprated actuators are the key. Perfectly possible with stock turbos from reading around. I think someone made about 600whp or 706hp with stock turbos on a dyno.

The Nissan Warrantee is definitely BS though. They may have a piece of paper but it ain't worth shit anymore.


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## thistle (Oct 27, 2007)

On a Mustang/Dynojet in the US perhaps. Here for similar quarter mile times and maps/specs we're getting about the same at the flywheel as they get at the wheels.


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## R33_GTS-t (Apr 27, 2005)

Oh not this argument again.


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## EvolutionVI (Sep 6, 2005)

R33_GTS-t said:


> Uprated actuators are the key. Perfectly possible with stock turbos from reading around. I think someone made about 600whp or 706hp with stock turbos on a dyno.
> 
> The Nissan Warrantee is definitely BS though. They may have a piece of paper but it ain't worth shit anymore.



The 706whp printout paper is worth as much as the warranty paper..:wavey:


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## thistle (Oct 27, 2007)

R33 GTS-t, I'm glad you think actuators can do 600 WHP on a UK dyno. Where then are the R35 GTRs you've tuned that have done 10 second quarter in the UK? AFAIK I've tuned the only two so far 

Or do I misunderstand you?


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## R33_GTS-t (Apr 27, 2005)

EvolutionVI said:


> The 706whp printout paper is worth as much as the warranty paper..:wavey:


Why is it that some people fail to read properly?


Go back and read what I've written again. It says 600whp, which is about 706hp flywheel factoring in a 15% loss.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> R33 GTS-t, I'm glad you think actuators can do 600 WHP on a UK dyno. Where then are the R35 GTRs you've tuned that have done 10 second quarter in the UK? AFAIK I've tuned the only two so far
> 
> Or do I misunderstand you?


You misunderstand that I have tuned any but here's one someone else made earlier. The 11.15 ET is fairly average with a not so brilliant start but I'm sure you'll agree that a 130mph trap roughly matches with the claimed and tested output. 








> Kit Includes:
> 
> Dual 3 to Single 3.5 Stainless Steel Midpipe
> 
> ...


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## thistle (Oct 27, 2007)

No fuel upgrade, our injectors are wide open at the top at that power at the flywheel.

The spark plugs, BOV make no difference. We control boost using the ECU. One of our ten second cars has an intercooler, one has actuators. We're all limited by the ECU's knock control on similar octane of fuel.

Our ETs are a few tenths faster, our terminal speed is 1mph slower.

But I would say we probably have about that power at the flywheel!

A standard car here on Dyno Dynamics with a map did 527 BHP. I have sent similar maps to the US and tuners are getting that at the wheels on Mustang dynos which read lower than Dynojets. The same map on an identical car set a better quarter mile time than something with 588 WHP on a Dynojet.

Everything aligns except the dyno figures. Dyno figures always have lied, always will.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> No fuel upgrade, our injectors are wide open at the top at that power at the flywheel.


Have you tried increasing the fuel pressure? Aren't the stock injectors about 600+cc anyway?



thistle said:


> The spark plugs, BOV make no difference. We control boost using the ECU. One of our ten second cars has an intercooler, one has actuators. We're all limited by the ECU's knock control on similar octane of fuel.
> 
> Our ETs are a few tenths faster, our terminal speed is 1mph slower.
> 
> ...


Well why don't you have a chat with some US dyno operators because they all seem to get about the same? Have a chat with Boost Logic on Supraforums and tell them that you think their dyno lies. Have a chat with all the other tuners getting upwards of 550whp too. The 588 is with higher octane. 545whp is the number with 93, hence the 640 (15% loss).

If the car's making 500hp flywheel as stock at 0.7 bar, how exactly can you increase boost to 1.2bar and only get an extra 27hp. The math on that doesn't add up unless your cooling system is heat-soaked or your dyno is knackered. Or do you mean 527whp?

So what exact time did you get?

Here's some more info. (560whp):
GTRCenter » Blog Archive » HKS GT570 + Cobb accessport – True crank horsepower

The 600whp was achieved with a Haltech ECU, see post #12
772whp on stock turbos - NAGTROC - The Nissan GT-R Owners Club

That's the highest ever achieved with stock I believe. The absolute limit. If you want a discussion on it find MindlessOath. Post #12 is his and he's on this forum.

I stand by what I said, 600whp is, give or take, the absolute theoretical maximum that stock turbos can flow. And actuators are the key because they allow you to hold more than about 1.0bar to the redline. And 650hp flywheel is achievable in a driveable package because several people of nagtroc have 550+whp packages with stock turbos and uprated actuators. I believe I've vindicated myself but am baffled at why you chose to turn a simple statement of fact into a research essay.


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## thistle (Oct 27, 2007)

Stock injectors are about 550cc, so based on 5.5cc/BHP they top out at about 600 BHP. Americans often claim lower BSFC.

You posted a video of 588 WHP and underneath it wrote 93 octane, if they are using higher octane then I'll credit them with a bit more, but not that much more on a UK dyno.

The standard car makes 478 BHP at 0.8 bar. At peak power the tuned example I quoted is running 1 bar, and I certainly do NOT mean 527 WHP.

You can read all about GTR times on a European R35 dyno times thread in this very forum. We're at number 1,2,3, need I go on?

I'm talking to American tuners all the time as I'm developing Cobb software for them. I've been collaborating with Americans on engine tuning projects for years. We don't discuss dyno results.

I do not believe the boost levels used on the GT570 kit make it do any more than 570 BHP on a UK dyno. 560 WHP just illustrates different reading dynos again.

600 WHP on Haltech with stock turbos likewise, more like 600 BHP.

MindlessOath is not a tuner I believe, he is an interesting poster on both forums who I like to read though.

You can stand by 600 WHP all you like, I would agree with you on a Dynojet or Mustang. Put it on Dyno Dynamics in standard shootout mode and see what you get.

Actuators are partly the key, but with the boost control we've rewritten in the ECU, a standard car can hold about 0.97 bar at the red line. AMS interestingly just posted that 2 PSI gain in boost with actuators over this level at 6200+ RPM gained no power, but there is debate over whether that was due to knock or heatsoak as others do find modest gains.

Using Cobb staged tunes we get nowhere near the US dyno figures. On standard cars we get nowhere near the US dyno figures. US and UK dynos are different. If UK users think they will get US dyno figures they will be bitterly disappointed. That is why I challenge it. However, on good quarter mile strips they will be competitive with their quarter mile times.

I'm less wet behind the ears with this than you may think, I simply do not believe US and UK dyno figures tally. I will not go silly with it and say we can't learn anything from US results or that I don't admire their tuning.

What actually matters is the difference in power before-after, Martin Donnon on NAGTROC caused a stir when he posted Mainline dyno figures, he had to use a huge multiplier to get them to read like a Dynojet the Americans were familiar with. I never post dyno plots on US forums because they just don't get that our dynos read much lower. At least with the GTR doing good quarters with its gearbox it removes a lot of the difference in quarter mile times across the pond as long as we use a proper strip like Santa Pod. There is much less UK experience with drag racing, so on manual cars not only do our dyno results look poor, but our quarter times and terminals do too. Not any longer.

I'd rather have 450 WHP that does 10s than 588 WHP that does 11s. What would you rather have?


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> Stock injectors are about 550cc, so based on 5.5cc/BHP they top out at about 600 BHP. Americans often claim lower BSFC.


They 60lb injectors. So that's about 120hp each or 720 together. Allowing for flow and restrictions this reduces to 690-700ish.



thistle said:


> The standard car makes 478 BHP at 0.8 bar. At peak power the tuned example I quoted is running 1 bar, and I certainly do NOT mean 527 WHP.


Well what kind of wheel to crank conversion are you using, as most stock GTRs dyno around 500+hp with 15% corrections. 400-420 on a mustang and 430-450 on a dynojet. Logic would dictate more than a 27hp gain from an extra 0.2bar. 27hp doesn't knock a second off quarter mile times.



thistle said:


> You can read all about GTR times on a European R35 dyno times thread in this very forum. We're at number 1,2,3, need I go on?


You do need to go on and drop half a second and be with the world's best. And I thought you said you were within 1mph of the trap speed in the video. The best trap on that list in the top 3 is 126mph. That's about 4mph down.



thistle said:


> I'm talking to American tuners all the time as I'm developing Cobb software for them. I've been collaborating with Americans on engine tuning projects for years. We don't discuss dyno results.


Well maybe you should instead of discussing them with me. 



thistle said:


> I do not believe the boost levels used on the GT570 kit make it do any more than 570 BHP on a UK dyno. 560 WHP just illustrates different reading dynos again.
> 
> 600 WHP on Haltech with stock turbos likewise, more like 600 BHP.
> 
> You can stand by 600 WHP all you like, I would agree with you on a Dynojet or Mustang. Put it on Dyno Dynamics in standard shootout mode and see what you get.


Maybe it is whp. Maybe this is why your traps are 4-5mph down.



thistle said:


> Actuators are partly the key, but with the boost control we've rewritten in the ECU, a standard car can hold about 0.97 bar at the red line. AMS interestingly just posted that 2 PSI gain in boost with actuators over this level at 6200+ RPM gained no power, but there is debate over whether that was due to knock or heatsoak as others do find modest gains.


Sounds like the ECU has several ways to kill your fun through boost cutting, AFR and timing but at the end of the day an Impreza Sti can make over 300hp, probably 350hp, using a single one of these turbos. 



thistle said:


> Using Cobb staged tunes we get nowhere near the US dyno figures. On standard cars we get nowhere near the US dyno figures. US and UK dynos are different. If UK users think they will get US dyno figures they will be bitterly disappointed. That is why I challenge it. However, on good quarter mile strips they will be competitive with their quarter mile times.


So how much power do you think that a stock gtr, weighing 1740kg and running [email protected] has then? 473hp crank? Even with a great gearbox, I ain't buying that. There's lighter RB26 GTRs with around 600hp settling for those numbers. Admittedly the driver is a factor but even so.



thistle said:


> I'm less wet behind the ears with this than you may think, I simply do not believe US and UK dyno figures tally. I will not go silly with it and say we can't learn anything from US results or that I don't admire their tuning.


It sounds to me that you need to meet with them and have a proper dyno comparison session. Arguing with me won't solve anything. Ask anyone on this forum who's tried it. 



thistle said:


> What actually matters is the difference in power before-after, Martin Donnon on NAGTROC caused a stir when he posted Mainline dyno figures, he had to use a huge multiplier to get them to read like a Dynojet the Americans were familiar with. I never post dyno plots on US forums because they just don't get that our dynos read much lower. At least with the GTR doing good quarters with its gearbox it removes a lot of the difference in quarter mile times across the pond as long as we use a proper strip like Santa Pod. There is much less UK experience with drag racing, so on manual cars not only do our dyno results look poor, but our quarter times and terminals do too. Not any longer.


You say tomayto, I say tomarto. But why potayto?



thistle said:


> I'd rather have 450 WHP that does 10s than 588 WHP that does 11s. What would you rather have?


I rather be able to recognise that a good quarter is all in the first 60ft and that no amount of tuning will make up for a bad launch and realise that 0-130 in 11.1 indicates a more powerful car than 0-125 in 10.9. I'd also realise that comparing 3500rpm LC cars with 2500rpm LC cars in terms of ET is like comparing an easter egg with a chicken egg. The new LC might not make that must difference with the stock car but with increased power it changes everything. 3500rpm LC cars could easily dip below 3s 0-60 with increased power. Trying to get below 3s 0-60 with the 2500rpm LC system is like trying to put marble through a cheese-grater.

And frankly I don't give a shit how fast I can do a quarter, I'm more interested in how fast I can get from 60-100 or 60-130, as that's what helps me overtake. Stop-racing is for people who stop too much.


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## cleethorpes (Sep 30, 2008)

handbags at dawn....


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## mindlessoath (Nov 30, 2007)

this is totaly false 650bhp.

first and foremost you have to ask anyone who is doing this what the baseline is. then you have to see the differnce between HP, WHP, BHP, PS, KW or whatever.

i hate these advertising traps that people are going to fall into. plus anything done to a gtr is going to be denied warranty for that affected area.

IF you take 480 as your baseline that is very false, you must dyno and get the results, then using teh same dyno with the mods and the same correction factors if used, then you can say the power gained. 

most advertisers use an estimated drivetrain loss to drive up these numbers for advertising, so 15%, 20% whatever, the higher the guess of the number the higher they can adverstise. thats annother false trap.

look for hp gained over stock dyno pull from the same tuners dyno (if you look at other dynos they may have correction factors they didnt include in the graph), try to look at WHP not drivetrain loss guestimates. also the R35 has been proven to have just about 10% friction loss. with spikes in the boost on the dyno it sometimes goes a bit higher to about 12% or so. and nissan has made a statement and proof that there drivetrain loss is 10% as they use ultra low friction bearings and Dual clutch transmission etc.


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## thistle (Oct 27, 2007)

Best ET is listed there, not best trap which was 128mph in 10.9, and since we're splitting hairs the one in the video didn't actually break 130mph either did it, although some similar ones have, many don't. On stock actuators and injectors, with stock ECU boost control and considering how long we've had the cars in the UK that is respectable, have you done better on an R35?

I believe your source overestimates the size of the injectors. The injectors are wide open at 11.5:1 AFR on external wideband. And that is with appropriate ignition timing. I was after all the one who disassembled the stock ECU knock control so I should know how to get the best timing out of them when most tuners haven't even started logging it yet and most are oblivious to how much timing their ECUs are pulling out.

Yes I do believe the stock car is 478 BHP.

I tend not to use dynos to tune since I have found that best acceleration on turbo engines often does not tally with the tune that gives the best dyno figures. Dynos are simulators, and usually poor ones at that. The airflow, loading, cooling, tyre deformation are all unrealistic. The fact that a standard car on one dyno can run higher power than a well tuned car on another that accelerates faster proves it to me.

If you have timing box equipment it is susceptible to question, just like dynos. Quarter mile times with proper certification tend to be better accepted, but I agree rolling acceleration is more important. The day I took my Subaru to a dyno, had 80 BHP less than a similar weight car and then pulled six car lengths on him on an airfield afterwards, repeated with swapped drivers, was the day I stopped taking too much notice of dynos. The car was tuned for maximum safe acceleration, did not knock in road or track use, but did on the dyno. GTRs are difficult to properly dyno test, and the engine bay is crowded and hot. The transmission can cause all sorts of limp modes. Consistency can be difficult.

So I've got little ambition to resolve cross Atlantic dyno differences. Those that know, know. Occasionally I point it out and get drawn into debate. I'm probably too keen to waste my time shooting down dyno figures that don't square with what I call reality. But we all know big numbers sell, and that is the real reason they are used.


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## thistle (Oct 27, 2007)

Nissan GT-R Injector Flow Test Comparison and Future Upgrades - NAGTROC - The Nissan GT-R Owners Club

Here is an actual GTR injector flow test result. 570cc. So 10% less than your 60lb claim, and using a 5% higher BSFC you start to get some of the figures more realistic. Interestingly from the NAGTROC thread where you quoted Martin's 60 lb claim, the tuners all seemed to agree with the power figures on their dynos, all from high reading dynos IMHO.

The GTR is fast enough without all the unrealistic/mythical power figures. I'd rather understate my power and surprise with acceleration.


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## thistle (Oct 27, 2007)

http://www.gtr.co.uk/forum/attachments/3322d1250071532-dyno-results-quarter-mile-time-dyno.jpg

Here is a Dyno Dynamics showing a standard car at 479 BHP.

It is the only plot I have of the GTC Stage 2 99 RON map which is 528 BHP although this was without the exhaust. Less of a gain than you might expect from looking at other claims, but the same map (also on a stock car without the exhaust) has done 125mph terminals.

Yet we read of 513 WHP on Mustang... also doing 125 mph terminal.

513 WHP vs 528 BHP, could they be the same?

If the Dyno Dynamics had the WHP on it, we could probably find a stock US car on Dynojet that has more WHP. Does that make it faster?

There are all sorts of ways you can cut this.


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## R33_GTS-t (Apr 27, 2005)

mindlessoath said:


> Also the R35 has been proven to have just about 10% friction loss.


No it hasn't and please don't show me that effort where they measured drivetrain drag on rundown. If you want to use that effort then please press the ends of your fingers on to rough sand paper and drag them back and forth slowly. Then do the same fast and see if you record the same skin loss.

This 650hp may well actually be a 5hp lawn-mover engine that's been slotted into a crashed R35 that's been welded to a G35 but 650hp is possible with stock turbos.



thistle said:


> Best ET is listed there, not best trap which was 128mph in 10.9, and since we're splitting hairs the one in the video didn't actually break 130mph either did it, although some similar ones have, many don't.


0.05mph? Seriously? You should know that it takes a lot of power to make 2mph on trap for a similar time. What was the 128mph ET?



thistle said:


> On stock actuators and injectors, with stock ECU boost control and considering how long we've had the cars in the UK that is respectable, have you done better on an R35?


Never said I could. You started this whole affair by incorrectly stating that 650hp flywheel couldn't be achieved on stock turbos, which is still incorrect despite your efforts to diversify the argument. Didn't Amuse bloody measure 550+whp with stock turbos anyway. What am I even arguing about here? Is Amuse's dyno faulty too?



thistle said:


> I believe your source overestimates the size of the injectors. The injectors are wide open at 11.5:1 AFR on external wideband. And that is with appropriate ignition timing. I was after all the one who disassembled the stock ECU knock control so I should know how to get the best timing out of them when most tuners haven't even started logging it yet and most are oblivious to how much timing their ECUs are pulling out.


Well it looks like BoostLogic's GTR is in defiance of your 600hp (510whp) calculation and Amuse's GTR is too.



thistle said:


> Yes I do believe the stock car is 478 BHP.


Well I'm afraid that's mathematically impossible. The fact a 1740kg car makes a quarter in [email protected]+ with less than 600hp is a miracle atributable to the gearbox. Making that time with 478hp would require divine intervention. By that logic every stage 1 skyline GTR would be in the high 11s. Nissan achieved a lot through science but stopped short of outright magic. Funny how pretty much none of the 10% magic men dispute that their quoted torque output is total bollocks.



thistle said:


> I tend not to use dynos to tune since I have found that best acceleration on turbo engines often does not tally with the tune that gives the best dyno figures. Dynos are simulators, and usually poor ones at that. The airflow, loading, cooling, tyre deformation are all unrealistic.


Yes. I'm not a tuner and even I know that. They also don't do well at measuring performance when not on WOT. They're a place to start before going on to the road.



thistle said:


> The fact that a standard car on one dyno can run higher power than a well tuned car on another that accelerates faster proves it to me.


Well of course it will. That's like saying that your quarter mile will be slower if you run it up a 1:3 gradient. But dynos of the same make should give approximately the same results under the same ambient operating condition if they're in the same state of repair and configuration. But yes it's best to use them to measure performance differences between mods. However, given that they don't necessarily measure true acceleration potential maybe you should test your cars with 40-95 and 60-125 runs in 3rd and 4th on a local bypass.



thistle said:


> If you have timing box equipment it is susceptible to question, just like dynos. Quarter mile times with proper certification tend to be better accepted, but I agree rolling acceleration is more important.


If you don't configure it correctly it becomes more open to question but then couldn't you also question track times since under NHRA rules a track can vary by up to 12ft in altitude between start and finish. A slight uphill to give better traction at the start, with maybe 15ft of downhill for the last 350yards.:flame: Then you've got windspeed and altitude and temperature and humidity.:flame: So in the end a track time is also full of shit unless you measure on the same track on the same day but even then the temperature or altitude could unreasonably advantage or disadvantage a turbocharged car against an NA car, especially a turbocharged car with a small engine, or with poor cooling.:flame::flame::flame:



thistle said:


> The day I took my Subaru to a dyno, had 80 BHP less than a similar weight car and then pulled six car lengths on him on an airfield afterwards, repeated with swapped drivers, was the day I stopped taking too much notice of dynos.


Well you tend to use more than 1rpm of a car's powerband - that could also have had a bearing.



thistle said:


> The car was tuned for maximum safe acceleration, did not knock in road or track use, but did on the dyno.


Usually the otherway round from what I've heard, especially with the sort of boost spikes and early spool you can get from uphill acceleration in a high gear.



thistle said:


> GTRs are difficult to properly dyno test, and the engine bay is crowded and hot. The transmission can cause all sorts of limp modes. Consistency can be difficult.


I'll take your word for it.



thistle said:


> *So I've got little ambition to resolve cross Atlantic dyno differences.* Those that know, know. Occasionally I point it out and get drawn into debate. I'm probably too keen to waste my time shooting down dyno figures that don't square with what I call reality. But we all know big numbers sell, and that is the real reason they are used.


Well you really should because I'm tired of these discrepancies and they're always going to be here until someone takes a car over there, or vice-versa, and takes some measurements.

Here's another one, check the signature. 551whp up from 420whp:
http://www.nagtroc.org/forums/index.php?s=&showtopic=30401&view=findpost&p=423377


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## thistle (Oct 27, 2007)

2mph is a nice improvement, but it is on a different strip on a different day. There can be that much variation on the same car run to run. Terminal speeds are not as technique independent as people claim, although the GTR gearbox does reduce the variation. It seems you agree with me that no method is perfect.

I've posted the 479 BHP dyno plot in post #19. On a similar power Subaru with 450 kg less weight I got the same quarter mile time and terminal that a standard GTR gets. It didn't help that the gear ratios were too short, I had a large turbo on a small engine with a limited red line due to stock internals, and I had four changes in the first 8 seconds, but it certainly helps the GTR that the gearchanges are not only very fast but the turbo remains on full boost throughout.

I've seen 12% coastdown losses on Subarus and Mitsubishis on Dastek AWD dynos. Had the gearbox not complained on the GTR, it might have been possible to see what the GTR was, but 550 WHP there might tally more with American dynos, but probably only be just over 600 BHP. I'm also not a believer in WHP figures and like the coastdown run, as whilst it is not perfect, it reduces bias due to gearing, transmission oil temperature, tyre pressure/temperature/compound/tread depth, strap down tension, roller spacing. I have examples of "tuning" that shows a gain over 75% of which was due to these factors rather than an increase in engine output since the "tune" was running only a little more boost but too rich and was retarded from the baseline. The increase in boost and consequent increase in mass airflow were nowhere near sufficient to give the claimed benefit. Fraud or stupidity, or a combination, I'm not sure, but it made me even more skeptical of dynos than I was before.

I do think 650 BHP is optimistic on Dyno Dynamics, Dastek or Maha. I'm sure other dynos can do it, but I'm used to lower reading dynos that tie closer with manufacturer's claims.

I do test acceleration on the road in as safe and repeatable fashion as I can. Without slip, an RPM or accelerometer log can be quite useful to determine tuning improvements. If it goes faster, I like it.

Re powerband, the other car wasn't lacking power band on the dyno at all. It had much greater area under the curve, but accelerated slower.

I could put my Subaru around Knockhill for multiple laps without knock on a TMIC on as hot a day as you get in Scotland, charge temperatures were below 50C. On a dyno even with a fan on the TMIC it hit 88C after two runs. Even with a FMIC it would det on rollers when tuned properly for road or track.

Shipping cars across the Atlantic isn't necessary when I send over a map with the same contents to the US and it makes much more power on a Mustang dyno.

So no method of comparison is perfect, but some dynos are reading much higher than others. Is this really news to you?

Perhaps I shouldn't even mention that I'm even more cynical about torque even from UK dynos.


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## mindlessoath (Nov 30, 2007)

Stop trying to use crank hp guesses. Just read whp and dyno as stock and dyno modified.

If u want drivetrain losses included don't guess them use a dyno like maha or hyper power which calculate the loss. There is always margin of error regardless but those are better than guesses just for advertising sake.

The max these turbos can push is aprox 150hp (give or take from evidence from tuners already) over stock what happens then is the turbos are so small they start spitting hot air and will eventually cause damage if the system is not cooled off and properly maintained under a lot of hard use.

This car can see 650 crank hp at 10% friction loss but not the one in the link in the original post. - the sp engineering car did 620 crank hp and it was about a year ago or the begining of the year iforget - with time technology gets better.

The haltech showed 163hp safely on stock turbos and mods with early beta versions, but to many bugs so it had to be tuned down until the next version comes out in the next week.

so your magic number is the stock turbos put out approx 150 over stock give or take. quarter mile pass will depend greatly on so many differnt factors.

annother note, JohnTurbo a usa tuner had s simular setup including meth injection and NITROUS and alot of it. he ran much higher hp but his engine blew up because of it. so its safe to say that he found the limit... whats a safe limit? you can run a very high hp on a dyno or on the drag but if it brakes, that high hp means nothing but death to the engine, right?


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## thistle (Oct 27, 2007)

> Here's another one, check the signature. 551whp up from 420whp:
> http://www.nagtroc.org/forums/index....dpost&p=423377


Can't see the signature you mean, but I can see the HKS claim of 501 PS to 601 PS. If the package gives 100 BHP, then on the Dyno Dynamics that did 479 BHP stock here you'd expect about 579, or if the package gave +131 like I think you mean by the signature you mentioned, then 610 which I believe to be right on the limit of the stock turbos. I'm not going to do an MLR fudge factor and multiply up the gain by some mythically inflated loss figure as I suspect a +131 WHP gain is not going to be much more than +131 BHP as most of the losses are speed rather than power related.

Funnily enough I was sent a log today from a GT600 kit. The boost and airflow level at the top had a 90% injector duty cycle where we would be at 100% without using the uprated fuel pressure (the level of increase isn't openly documented, but seems like 20%).

So on dynos that read stock what the factory claim, I honestly think we're all done at about 600 BHP on the stock turbos on pump fuel. I just can't believe 700 BHP could happen on these dynos with the stock turbos.

IIRC a Cosworth employee who posted on here suggested the plasma liners are likely to peel at TDC much over 600 BHP, but I can't quite remember how he worded it, but it sounded pejorative about dyno figures and suggested a real 600 BHP was rather different to a quick buzz on a chassis dyno.

They have the same issues in the Porsche world, a poster I think by the name of TB993t on Pistonheads and Rennlist goes to very expensive German tuners who give him packages that run a power level that it will do continuously, yet his car is faster than others than claim 100s of horsepower more. I honestly think these serious tuners who tune in such an overengineered manner laugh at some of these 10 second dyno pulls.


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## thistle (Oct 27, 2007)

mindlessoath said:


> Stop trying to use crank hp guesses. Just read whp and dyno as stock and dyno modified.
> 
> If u want drivetrain losses included don't guess them use a dyno like maha or hyper power which calculate the loss. There is always margin of error regardless but those are better than guesses just for advertising sake.
> 
> ...


I'll not subscribe to WHP figures for the good reasons I mentioned. I'll take my coastdown runs, and I'm not the only one. It is one thing to say what the car puts down at the wheels, but you'd be better calculating that from real world acceleration than from a dyno where you've got a poor simulation of reality.

I'd accept the possibility of +120 to +150 BHP over stock at a real push, using good fuel, selecting the best dyno run from a set and maybe some good weather conditions or dyno fudge factors. I bet it would very quickly fatigue with all the coolers you could throw at it, and would only manage it on dynos that don't really load up the engine for very long. So it isn't really genuine. The stock power will be much more repeatable, as would selection of properly sized turbos for the job. Just to get +100 BHP over stock you get signals when tuning that it is at a sensible limit. They are:

1. Exponentially rising wastegate duty cycles to hold boost, even with actuators
2. The tone and smoothness of the engine, it feels like you are forcing a lot of air through small turbines
3. Knock retard at high engine speeds whereas usually it would be midrange
4. Decreasing gains in acceleration (or power on a dyno LOL) for each increment of boost


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## mindlessoath (Nov 30, 2007)

yes, that is correct. search username "WINK" without quotes. he has posted alot of usefull bits you will want to checkup on. its because of the size of the turbos, larger turbo's will not spit out such hot air at lower levels of boost so it can handle more heat hence less problems with the plasma sprayed iron sleeves. after about 150hp increase your going to want to add intercoolers and oil cooling and radiator and what not. any launching will require transmission mods of some sort, a transmission cooler at minimum probably some better fluid too. its the larger picture tho.

do you think im wrong or just BSing tho? cause i am learning... and would like to be corrected if im wrong.


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## mindlessoath (Nov 30, 2007)

thistle said:


> I'll not subscribe to WHP figures for the good reasons I mentioned. I'll take my coastdown runs, and I'm not the only one. It is one thing to say what the car puts down at the wheels, but you'd be better calculating that from real world acceleration than from a dyno where you've got a poor simulation of reality.
> 
> I'd accept the possibility of +120 to +150 BHP over stock at a real push, using good fuel, selecting the best dyno run from a set and maybe some good weather conditions or dyno fudge factors. I bet it would very quickly fatigue with all the coolers you could throw at it, and would only manage it on dynos that don't really load up the engine for very long. So it isn't really genuine. The stock power will be much more repeatable, as would selection of properly sized turbos for the job. Just to get +100 BHP over stock you get signals when tuning that it is at a sensible limit. They are:
> 
> ...


i can agree with that. the other cars that had 130 to 160 hp gain over stock were probably all using race gas, i know the sp engineering one was and im sure others were too.

i agree coast down method is good but i would like tuners to say they are using this method instead of claiming nothing and confusing everyone cause so many dyno's are differnt.


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## thistle (Oct 27, 2007)

We're all learning  Agree with what you say, better cooling and larger turbos with high octane fuel at the same output would give lower peak cylinder pressures, keeping the boost and torque sensible should reduce the strain on the liners. You could have fewer/smaller spikes in cylinder pressure at 800 BHP done well than 550 BHP done badly.

You're just used to a different dyno currency than me. Running 390 WHP stock would not surprise me, I think it would you?


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## R33_GTS-t (Apr 27, 2005)

mindlessoath said:


> Stop trying to use crank hp guesses. Just read whp and dyno as stock and dyno modified.
> 
> If u want drivetrain losses included don't guess them use a dyno like maha or hyper power which calculate the loss. There is always margin of error regardless but those are better than guesses just for advertising sake.


So instead of using a commonly recognised 15%, use a dyno, which is noted for inaccuracy, to provide an incorrect estimate of power loss.

I give up. It's all bollocks. I'll only believe power claims after driving the cars on the local bypass and hereby issue a decree stating that this is how all GTR performance, skyline or otherwise, shall be measured from herein. My arse shall provide the bhp figures for both wheel and flywheel and from hereto my balls shall determine knock and hence whether AFR should be reigned in.



thistle said:


> 2mph is a nice improvement, but it is on a different strip on a different day. There can be that much variation on the same car run to run. Terminal speeds are not as technique independent as people claim, although the GTR gearbox does reduce the variation. It seems you agree with me that no method is perfect.


No method is perfect but I think the car with the 130mph trap has more power. Again, what was your 128mph ET?



thistle said:


> I've posted the 479 BHP dyno plot in post #19.


Looks like boost is falling off after 5000-5500rpm given the huge fall in torque vs stock fall-off. Even the power dips at 5500rpm. Must be something funny in the boost, AFR or timing or the actuators refusing to do as they're told. That dip shouldn't happen.



thistle said:


> I do think 650 BHP is optimistic on Dyno Dynamics, Dastek or Maha. I'm sure other dynos can do it, but I'm used to lower reading dynos that tie closer with manufacturer's claims.


It all depends on what loss you apply. I did state that I was using a 15% loss fairly early on in fairness. Many would still regard that as conservative for an AWD car. Hell, an RS4 only makes 350hp at the hubs on a Rototest.



thistle said:


> Shipping cars across the Atlantic isn't necessary when I send over a map with the same contents to the US and it makes much more power on a Mustang dyno.


Ah but are they playing with it afterwards?



thistle said:


> So no method of comparison is perfect, but some dynos are reading much higher than others. Is this really news to you?


Nope, I knew Mustangs read higher than Dynojets and hub dynos generally get closer to flywheel/manufacturers figures.



thistle said:


> Perhaps I shouldn't even mention that I'm even more cynical about torque even from UK dynos.


Well torque is gear-dependent (even when we're talking about the torque at the flywheel), especially on turbocharged cars, boost spikes and all. 433lbft is some way off though.  Power and torque is pretty much on a 1:1 ratio for cars with stock turbos.

Did I mention that I believe there's probably a 50-60hp variation in stock power outputs anyway. Just look at the 1s difference in recorded 0-124mph times. So a tune on one car will probably yield completely different results on another anyway. And how does octane (MON+RON)/2 map to RON. 99 RON could yield a variation of MON and vice-versa. Some 93 Octane could be nearer 101-102 RON. A 60hp variation in stock + variation for good fuel and....


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## mindlessoath (Nov 30, 2007)

thistle said:


> We're all learning  Agree with what you say, better cooling and larger turbos with high octane fuel at the same output would give lower peak cylinder pressures, keeping the boost and torque sensible should reduce the strain on the liners. You could have fewer/smaller spikes in cylinder pressure at 800 BHP done well than 550 BHP done badly.
> 
> You're just used to a different dyno currency than me. Running 390 WHP stock would not surprise me, I think it would you?


ya alot of dyno's here run 390hp give or take. i like to refrence forged here in the states but i have seen many other dyno's output all sorts of wild numbers
Nissan GT-R Horsepower Torque Dyno Sheets - DragTimes.com
(these dyno's listed have to be taken with a grain of salt, alot dont state correction factors when they do use them and others use a cobb tune and dont state it etc.) some are done in third gear while others in 4th gear. sometimes they dont state the gas used or if they were done in america or not.

i dunno what this guy is arguing anymore. 15% because a tuner said so... lol, those tuners are here to make money and advertise, relax buddy.

btw thistle, with your 479bhp what would the same run be at the wheels? what kind of friction loss does that calculate to? or does that dyno not do that kind of work? is it closer to 10% or closer to 15% or do u have an exact?

here are the results from this run down test from hyper power dyno, more than one article, shows approx 10 to 12% give or take
http://www.gtrcenter.net/?s=hyper+power


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## thistle (Oct 27, 2007)

If you look at the detailed specs of Greenergy Tesco 99 and V-power, it is competitive with US 93 PON.

If you look at the wastegate duty cycle and boost curve of a stock GTR you'll see why it has more power than torque when measured in BHP and lbft. The wastegate duty cycle is a mirror image of most stock turbo engines.

B7 RS4 just don't make their quoted power on even optimistic dynos from what I've seen.

There was nothing funny about the car that ran 479 BHP on the dyno when I logged it on the road afterwards. Stock and tuned, it had normal boost, AFR, timing behaviour. On the stock dyno plot it is not dipping, on the tuned examples it is. It was probably pulling timing on the dyno with the tuned maps, a lot of cars are, but it is only since then that knock has become loggable using the Accessport.

The 128mph timeslip is in the same thread somewhere, it was only just over 128 just like the one you linked was only just under 130. But nevertheless the difference is less than 2mph not the 4mph you were suggesting  They make the excuse that they had poor traction, I make the excuses that it is a different track, different day, it was our driver's first time ever driving on a drag strip, he had poor traction too and no LC1, but I don't need to make an excuse at all really about tuning the first two GTRs in Europe in the 10s to be quite honest  I think you'd have me apologising for not hitting 130 mph if you had your way


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## mindlessoath (Nov 30, 2007)

R33_GTS-t said:


> Did I mention that I believe there's probably a 50-60hp variation in stock power outputs anyway. Just look at the 1s difference in recorded 0-124mph times. So a tune on one car will probably yield completely different results on another anyway. And how does octane (MON+RON)/2 map to RON. 99 RON could yield a variation of MON and vice-versa. Some 93 Octane could be nearer 101-102 RON. A 60hp variation in stock + variation for good fuel and....


There will always be a variation due to the way the ecu works. it calculates things based on the CAN system and its hooked up to so many differnt systems and sensors. plus differnt octains will be differnt. the car even changes ecu tune based on sea level iirc. thistle can really clue you into this as i know he knows the inner workings of the ecu.

iirc VDC and the TCU play a big roll in the system too, and that will change things when driving.


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## thistle (Oct 27, 2007)

mindlessoath, I wish I knew the WHP on that plot. Dyno Dynamics just uses a pre-programmed fudge factor rather than a coast down, but I think it is 0.82 which would put it under 400 WHP, for the MLR (lancerregister) they manually change it to 0.78 and shockingly some do the same for torque too.


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## mindlessoath (Nov 30, 2007)

so its safe to say that friction loss on the gtr is about 10% give or take a small margin of error? if you were to make an assumption that is. were not trying to make it a fact (even tho nissan has stated 10% loss as a fact)


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## thistle (Oct 27, 2007)

If Nissan has stated it, I would go with it over anything else.

I don't believe the flywheel power is terribly high, I suspect it is the gearbox, traction, low losses that help the acceleration at low speeds, and the decent aero at high speeds. The Cd is lower but the frontal area higher than a 997 turbo which as standard with the same power does seem outdrag the GTR slightly at high speed, which I presume is due to the 120kg approx weight difference. Despite its better power to weight ratio, they are similar at lower speed, presumably because neither manual nor tiptronic shift as well as the GTR.


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## mindlessoath (Nov 30, 2007)

you can read up on some of the aero here:
NISSAN GT-R press information...
the finer details are left out, but its better than the porsche due to its PM design. it sorta explains it.

anyways here is nissans claim
Nissan 360 Day 1: Things I've Learned | Car News Blog at Motor Trend

Nissan engineers insist the GT-R really does only have 480 hp. Motohiro Matsumura, president of Nissan Technical Center North America, Inc. in Farmington Hills, Michigan, says our dyno test story, which revealed the GT-R develops 430 hp at the wheels, is basically right. But he insists our estimate of a minimum 15-percent friction losses -- which suggests the GT-R is making 507 hp -- is wrong. Matsumura-san says ultra-low friction bearings in the wheel hubs and transmission, plus the careful alignment of the all-wheel-drive system's propshafts, mean friction losses are reduced to an unprecedented 10 percent or so. We're going to get a GT-R back and conduct some coast-down tests to see if he's right.

then here is there friction loss dyno testing
2009 Nissan GT-R Horsepower: The Truth - Nissan GT-R Dyno Run - Motor Trend

also maha dynos have got about the same results 478hp give or take a few on differnt dyno's from differnt articles that factor in actuall friction losses not guestimates. here is one example of many http://www.supercars.net/PitLane?viewThread=y&gID=0&fID=1&tID=175997
i cant find all the rest.


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## thistle (Oct 27, 2007)

Mitsubishi Lancer Register Forum - View Single Post - 30-130 Gear Changes (might need to log in to see the attachments shows a typical and fast gearchange). It shows 0.9 seconds with sub-optimal acceleration on the typical, and 0.4 seconds on the fast.

This makes up for the R35's porky weight and explains a lot of why it accelerates like considerably lighter cars with the same power.

There is no need for ridiculous power claims to explain the GTR's performance.


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## Kamae (Jun 15, 2009)

Jesus - I bet you guys are a laugh a minute down the pub!


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## R33_GTS-t (Apr 27, 2005)

mindlessoath said:


> i dunno what this guy is arguing anymore. 15% because a tuner said so... lol, those tuners are here to make money and advertise, relax buddy.


Why don't you either prove otherwise or forget about it. I didn't start this argument. I made a simple statement which remains true and even stated what loss I was using to avoid this discussion. There's a whole list of manufacturer's cars tested here on a hub dyno and most 2WD cars exercise the sort of 10% loss that you claim. 10% is BS end of. I'm sure Nissan only quoted it to promote discussion about the GTR.

Powertrain Performance Graphs - Rototest Research Institute

That's at the hubs not the wheels, so should have far less loss. The problem these days is that some tuners use conservative conversions as a badge of honour, as if it's a mark of how genuine they are. 10% loss for an AWD car is fantasy land. You can't make 195mph in an AWD car the size of a GTR with 473hp as Motortrend did. Even with an immensely good Cd, the size out-weighs that.



mindlessoath said:


> here are the results from this run down test from hyper power dyno, more than one article, shows approx 10 to 12% give or take
> GTRCenter » Search Results » hyper power


Believe 10% because a dyno tells you so? Having just spent 5 hours arguing about the inaccuracy of dynos, you're prepared to accept their word on losses.:chuckle:

That method is BS as I've already pointed out and explained to you in an earlier post. The drivetrain drag under load isn't the same as the drivetrain drag off load. Then there's the heat dissipation to examine and have you ever heard of a silent engine?

As I've already explained it doesn't take a genius to reason that this method is incorrect. Press your finger on to a table and drag it across slowly. Now, whilst exerting the same downwards force with your finger, do it fast. The real world isn't a physics class where opposing forces remain constant under all load conditions. These guys are merely marketing a product. Their claim to be able to measure losses on rundown is loltastic to anyone with a sound knowledge of physics.

Please do read.
http://www.geartechnology.com/pa/members/sepoct05/section4.pdf
http://artec-machine.com/documents free/efficiency gears/power_plant_effic.htm


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## thistle (Oct 27, 2007)

That is an interesting paper on gear losses that I think actually backs up the coastdown method. The sliding+rolling friction losses vary by about 11kW and the total loss by about 18kW in a power input range of 2238 to 8952kW. Do you think that is significant?


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> If you look at the detailed specs of Greenergy Tesco 99 and V-power, it is competitive with US 93 PON.


Got those specs? I wouldn't have thought that Tesco 99 was comparable with V-Power 99. It isn't in most side-by-side tests, moving back to the subject of dynos.



thistle said:


> If you look at the wastegate duty cycle and boost curve of a stock GTR you'll see why it has more power than torque when measured in BHP and lbft. The wastegate duty cycle is a mirror image of most stock turbo engines.


Surely you can see that there's something wrong at 5500rpm though. To see a power curve drop (as well as torque) and then come back and rise is unusual. The mid-range torque together with that unusual drop and rise indicate that more power is possible at the top end.



thistle said:


> B7 RS4 just don't make their quoted power on even optimistic dynos from what I've seen.


They seem to make rough 414hp-worth of acceleration though, often embarassing earlier R8s up to 100mph.



thistle said:


> There was nothing funny about the car that ran 479 BHP on the dyno when I logged it on the road afterwards. Stock and tuned, it had normal boost, AFR, timing behaviour. On the stock dyno plot it is not dipping, on the tuned examples it is. It was probably pulling timing on the dyno with the tuned maps, a lot of cars are, but it is only since then that knock has become loggable using the Accessport.


Knew there was something up. 



thistle said:


> The 128mph timeslip is in the same thread somewhere, it was only just over 128 just like the one you linked was only just under 130. But nevertheless the difference is less than 2mph not the 4mph you were suggesting  They make the excuse that they had poor traction, I make the excuses that it is a different track, different day, it was our driver's first time ever driving on a drag strip, he had poor traction too and no LC1, but I don't need to make an excuse at all really about tuning the first two GTRs in Europe in the 10s to be quite honest  I think you'd have me apologising for not hitting 130 mph if you had your way


I'd have you apologising for not making 9s and 140mph but that's just me. 



mindlessoath said:


> There will always be a variation due to the way the ecu works. it calculates things based on the CAN system and its hooked up to so many differnt systems and sensors. plus differnt octains will be differnt. the car even changes ecu tune based on sea level iirc. thistle can really clue you into this as i know he knows the inner workings of the ecu.
> 
> iirc VDC and the TCU play a big roll in the system too, and that will change things when driving.


Having seen some GTRs make 0-124mph in 11.5s and some (well one anyway) take over 13s, I would say that there's a lot of variance in GTRs. 478bhp may well simply be a figure that undercuts the worst of GTRs, such that no customer is short-changed on quoted hp. I believe the average is about 520hp with some making 550hp. I know that all the things you mention make a difference but there's tolerance in the actual engines themselves as well. I'm sure that if you took 100 stock GTRs side-by-side and ran them some cars would be much faster than others.

Not as bad as the Lister Storm though. You could made a decent super-mini out of the power difference between some of those engines.


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## cleethorpes (Sep 30, 2008)

calm down girls... put the nails away..

is this a ' my brain is bigger than your brain ' kinda thing..

as in my opinion ..this long two way rant battle is painting neither party in a particularly favourable light....unless petty is the name of the game..


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## thistle (Oct 27, 2007)

Tesco 99, which has 5% bioethanol (E5). Minimum: 99 RON (RON), 87 MON (=93 PON).

Shell V-power, no ethanol added. Minimum: 99 RON, 86 MON (=92.5 PON). Typical: 99.2 RON, 87.0 MON (=93.1 PON).

There is a pdf spec sheet somewhere for V-power with the above numbers, and info on Greenergy can be googled.

There is no dip in the stock plot at 5500 RPM, the 479 BHP one. Other GTRs on other Dyno Dynamics do similar - 476 on this one: http://www.gtr.co.uk/forum/1145467-post54.html

I do not believe any stock GTR is doing anything like 550 BHP on a dyno I believe and it is perhaps self-fulfilling as I would reject such a plot as ridiculous. I suspect this power level on some dynos will also see 10 sec quarters too. Some run a bit more boost than others, the stock boost control is quite lazy to correct errors, and not everyone's wastegates will be tensioned exactly the same, along with other tolerances, but not 70-75 BHP worth of difference.

cleethorpes, I was quite enjoying it until you interrupted


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## cleethorpes (Sep 30, 2008)

it's like a bloody episode of eggheads


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## thistle (Oct 27, 2007)

I don't have time to watch it, I'm too busy arguing on the internet


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> That is an interesting paper on gear losses that I think actually backs up the coastdown method. The sliding+rolling friction losses vary by about 11kW and the total loss by about 18kW in a power input range of 2238 to 8952kW. Do you think that is significant?


That's the difference between 25% load and 100% load, not 0% and 100% and it is operating at 1460rpm.

The second paper details a difference between no load and full load losses of nearer 50%. Working with 50hp = 10%, that's 25hp you're missing. Factor in an increase in oil drag for far higher shaft speeds 

Power - transmission losses, "calculated" or measured "Flywheel" B.H.P. figures?



> It can never be truly accurate though because there are actually MORE losses than this under load because one component of the losses depends on the actual torque being transferred. Gear teeth under high load "slide" against each other giving increased friction (although only minor due to the oil film) and the same applies to thrust bearings etc inside gearboxes and diffs. This method cannot know how much this happens as it measures the power required to turn tyres, gears, chains, etc whilst not under load conditions.
> 
> Rear (or front) diff / axle (car) losses -
> 
> ...


It's a well known fact that no wheel or hub dyno can measure power losses accurately. The only way to that is to remove the engine from the car. 
However sometimes if it looks like a duck and quacks like a duck, let's call it a duck. It looks like 500+hp and it quacks like 500+hp, so let's call it 500+hp, and when some stock cars have made 480hp at the hubs, there isn't really any sensible alternative.

This was probably the first ever test with an early 480ps car.
http://www.dragtimes.com/Nissan-GT-R-Timeslip-14208.html
That's 500+hp by any stretch of imagination or logic.


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## EvolutionVI (Sep 6, 2005)

@R33 GTS....: Forget all that american dyno BS.....a typical tune on a dyno with a Mitsubishi Evo 9 in US has near to 380whp,on stock internals,stock turbo and injectors.....in Europe we max out everything on the same car and come to 320whp(which is around 400 fwhp)...strangely the 1/4mile speeds of these cars are identical all over the world....should be different with 60 more horses to the wheels....dont you think?


GTR´s are the same all over the world,but the US gets allways more WHP then we get FlywheelHP.....with the same parts used...ok,it could be down to the programmer,but strange when a UK makes the softwareupdates and knows the maximums off everything.....how should someone in US do it any better then the guy who has the latest/best software??

Alex

PS: Do you believe the americans have been on the moon:nervous:


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## thistle (Oct 27, 2007)

The losses are already quite small (I was surprised how small) with 25% load though, how much difference can a few % load under deceleration make? It can't be more than the already small losses.

The second paper is also interesting, but also makes clear that the majority of losses are speed related, this is why I still favour a coastdown run if I have to use a dyno at all.

Engine dynos are a whole other kettle of fish. All these methods are plagued by difficulties.

I could believe that the some stock engines might be doing up to 500 BHP (flywheel), but I just don't see the variations in airflow and injector flow on standard logs to support much more variance than this. They don't accelerate incredibly at high speed as standard either (Alex posted some figures standard vs tuned and the high speed acceleration disappointed him compared to GTR competition) so I don't think they quack like a 500+ BHP car. A small increase in power changes that, as your papers show you've overcome the losses already and most extra power makes it to the tarmac. Additionally when you're becoming aero limited, even an extra 50 BHP can make a large difference to say a 150 to 180 mph time.

It comes down to using different yardsticks. Yes I would rather be conservative, it is more honest and you're not overselling anything (not that I actually sell anything myself anyway). We're already having to explain to people why identical staged maps on this side of the water don't do the power they expect from reading US dyno results.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> Tesco 99, which has 5% bioethanol (E5). Minimum: 99 RON (RON), 87 MON (=93 PON).
> 
> Shell V-power, no ethanol added. Minimum: 99 RON, 86 MON (=92.5 PON). Typical: 99.2 RON, 87.0 MON (=93.1 PON).


I've not seen any fuel comparisons work out better with Tesco 99.... ever.



thistle said:


> There is no dip in the stock plot at 5500 RPM, the 479 BHP one. Other GTRs on other Dyno Dynamics do similar - 476 on this one: http://www.gtr.co.uk/forum/1145467-post54.html


No there won't be on the stock plot. The dip is because the ECU doesn't like something that's changed. Fix that and you're aware. I note that you made [email protected], that's far better than the 527 you wrote about earlier.



thistle said:


> I do not believe any stock GTR is doing anything like 550 BHP on a dyno I believe and it is perhaps self-fulfilling as I would reject such a plot as ridiculous. I suspect this power level on some dynos will also see 10 sec quarters too. Some run a bit more boost than others, the stock boost control is quite lazy to correct errors, and not everyone's wastegates will be tensioned exactly the same, along with other tolerances, but not 70-75 BHP worth of difference.


I said 50-60hp. It all boils down to what you want to believe but when comparing a GTR's performance against other cars of similar power, even allowing for DCT, there's no way it lands out at 480hp, unless all other manufacturers are lying. Maybe the simple fact is that your dyno under-reads and I find it bizarre that you have 100% faith in it and no others.

As I've pointed out, a stock GTR has ran 0-124mph in 11.5s, others have been around 12.5s in virtually identical ambient conditions. That's ~50hp difference.


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## thistle (Oct 27, 2007)

It isn't my dyno, I would not want to own one, and if I did it would be the most miserable reading dyno ever because I wouldn't want inflated figures, and all the boy racers would argue with me why they had more power. I am merely showing you results from standard cars less than 480 BHP, and I don't think I'm ignoring masses of higher Dyno Dynamics ones, but I think David Yu had more.

The 571 BHP at 1 bar had no cats, a full exhaust system and was as custom tuned as the software could do safely at the time. The 527 BHP had four cats and was completely standard except a staged map.

Since we've started logging knock we've found that the staged maps have optimistic ignition timing, so the car is pulling timing on the road with them like a stock US car does on 91 PON. The dips in the dyno plot are explained by it probably pulling even more timing on the dyno as they usually do. However, a stock car on 99 RON hardly ever pulls timing on the road, don't have a log from a dyno to see whether it makes it pull timing.

Most GTRs are not running at the 12.5s times. I doubt these <480 BHP cars are either.

I just don't see the need for big figures, it feels dishonest to me. If you want to believe the cars I tune have more power than they do, I'll have to take that as a compliment.

I think I've said all I want to say, I'll pop into the thread another time to see if there is anything else interesting. Nice to talk to you, I have learned something


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> It isn't my dyno, I would not want to own one, and if I did it would be the most miserable reading dyno ever because I wouldn't want inflated figures, and all the boy racers would argue with me why they had more power. I am merely showing you results from standard cars less than 480 BHP, and I don't think I'm ignoring masses of higher Dyno Dynamics ones, but I think David Yu had more.


In this month's Evo his report mentions that another GTR (not his) made 506hp stock.



thistle said:


> Most GTRs are not running at the 12.5s times. I doubt these <480 BHP cars are either.


Most make around low 12s for 0-124mph but I think I've made my point. There is huge variation.



thistle said:


> I just don't see the need for big figures, it feels dishonest to me. If you want to believe the cars I tune have more power than they do, I'll have to take that as a compliment.


But is it dishonest? I think this feeling of a need to avoid dishonesty is getting more common and as a result we have increasingly more conservative loss estimates. Before long some tuners will be knocking out cars claiming 500hp flywheel that are faster than 600hp vehicles from manufacturers.



thistle said:


> I think I've said all I want to say, I'll pop into the thread another time to see if there is anything else interesting. Nice to talk to you, I have learned something


I can't believe this resulted in 4 pages.


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## R33_GTS-t (Apr 27, 2005)

Not wishing to harp on but here's a thread that roughly confirms my suspicions about a 50-60hp variation in stock vehicles.

Cobb AP, HKS resonated mid pipe, Jack Cecil (Horsepower Logic)custom tune - NAGTROC - The Nissan GT-R Owners Club



> I also want to add that my car does seem to be quite strong in stock form, as shown by previous runs at PBIR against another identically stock car. Jack also said he has seen stock cars on his Dyno run anywhere between 380 to 420.
> 
> It was a very good experience overall. Jack is a really nice guy, and really knows his tuning. I highly recommend him as a tuner, and HP logic in general.
> ....
> Baseline was 436 WHP, 375 WTQ


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## thistle (Oct 27, 2007)

No it just shows that dynos are inconsistent and flawed.

Not to take anything away from any achievements from tuners or that tuner or car in particular, but that sort of variation is not at all surprising considering atmospheric variations (whether "compensation" is used or not), different strapping, knock control effects, different tanks of fuel, tyre pressure/temperatures, gearbox oil temps.


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## Burning (Mar 11, 2009)

R33_GTS-t said:


> Not wishing to harp on but here's a thread that roughly confirms my suspicions about a 50-60hp variation in stock vehicles.
> 
> Cobb AP, HKS resonated mid pipe, Jack Cecil (Horsepower Logic)custom tune - NAGTROC - The Nissan GT-R Owners Club


All engines are ±3% from the claimed 478PS when they leave the factory (in theory).


R33_GTS-t said:


> You can't make 195mph in an AWD car the size of a GTR with 473hp as Motortrend did. Even with an immensely good Cd, the size out-weighs that.


I'm sure you can back it up with some cold hard calculations if that's true. Also Motortrend only did 192 mph.

As for 650hp being possible on stock turbos ...  
That's 35% over stock or 170 hp. I'll wait for the dyno sheet that shows it (with the baseline done in the same conditions on the same dyno).


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## thistle (Oct 27, 2007)

996 Turbo with a claimed 65 PS less (and AWD) does similar top speed (you'll find some claiming more, some less than the GTR). I don't have the Cd to hand but it is higher than the GTR IIRC, probably enough to allow a substantial frontal area difference to be comparable in CdA to a GTR, or not so much less than 65 PS would make up.

Nissan's claimed power and losses seem very realistic to me. I'd take them over tuning shop dynos that have an interest in putting out high numbers any day of the week.


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## David.Yu (Jun 28, 2001)

Crikey, I can't believe this thread has kicked off into such a philosophical discussion! 

Yes, the "other" stock car did dyno at 506hp when my Y-pipe but stock car measured 512hp. (407.3 AWHP)
After Stage 1 Cobb shelf map, mine measured 547hp (434FWHP) and the "other" 541hp.

I have to say, after years of testing lots of powerful cars, those figures make the 0-60mph in 3.2s and 0-100mph in 7.6s times I recorded just about believable.

But at the end of the day, I know, as all grown ups do, that rolling roads are only useful for measuring deltas for the same car at the same venue, and even then, only really if done on the same day.

The one thing I really can't believe, is the quoted 10% transmission loss. For a rear transaxle 4WD DCT set up? How can that possibly be more efficient than a conventional 2WD manual set up?

I asked Mizuno-san via Pistonheads and I await his reply with bated breath...


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## ScottyB (Jun 9, 2009)

My ears are burning, now i know why.........


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## R33_GTS-t (Apr 27, 2005)

Burning said:


> All engines are ±3% from the claimed 478PS when they leave the factory (in theory).


Just like the torque curve was completely flat from 3200-5200rpm a la the graphs in the brochure?



Burning said:


> I'm sure you can back it up with some cold hard calculations if that's true.


Of course you can't back it up with a calculation. That'll give you a ridiculously low power figure because it's not real life. In fact for what it's worth I'll run it through

P = Fv = 0.5 * 0.5645 * 1.225 * (86.67^3) = Oh look only 302whp. Do you seriously believe this calculation? Maybe the GTR has 40% losses. Of course Cd remains the same at high speed even though it can't because increased downforce is being produced on a 3-dimensional body and a component of that downforce points in the drag direction.

I know because I know what other cars with similar CdA products can do with the same power.



Burning said:


> Also Motortrend only did 192 mph.


195mph
YouTube - 2009 Nissan GT-R Top Speed TEST 2



Burning said:


> As for 650hp being possible on stock turbos ...
> That's 35% over stock or 170 hp. I'll wait for the dyno sheet that shows it (with the baseline done in the same conditions on the same dyno).


There's already a thread over on nagtroc. The BL car made 545whp. The debate is whether the transmission loss is 15% or a magical 10%.

Here's one with 572whp on a Mustang dyno, so even with the magical 10% that's near 650hp. Baseline = 426whp. 17.7psi
2009 Nissan GT-R HKS GT570 Dyno Sheet Details - DragTimes.com

602whp, (443whp baseline). 20psi
2009 Nissan GT-R Vivid Racing Dyno Sheet Details - DragTimes.com

In fact take a look down this list. Look for the ones where no turbo mod is stated. You can tell by the torque curve, which are standard turbos too.
Nissan GT-R Horsepower Torque Dyno Sheets - DragTimes.com

So even with the magical 10%, 650hp is possible (even if the car in post #1 doesn't have it). There's a great case of an 'I can't, so nobody can' attitude.

If a stock GTR really did have it's quoted power output, it'd be the first one that ever has in at least 2 decades. Why do you think Nissan were so quick to tell North America to forget about the ps to hp conversion? Because it's irrelevant.


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## cleethorpes (Sep 30, 2008)

yawn


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## cleethorpes (Sep 30, 2008)




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## R33_GTS-t (Apr 27, 2005)

David.Yu said:


> The one thing I really can't believe, is the quoted 10% transmission loss. For a rear transaxle 4WD DCT set up? How can that possibly be more efficient than a conventional 2WD manual set up?


I know. When you consider that a RWD transaxle system has 1 driveshaft, a gearbox, 1 differential and 2 driving wheels and supposedly has 15% loss, yet the GTR, with 2 drivshafts, a gearbox, 3 differentials and 4 driving wheels apparently only loses two thirds as much. Unless these low friction bearings are electromagnetic and float in a cushion of air I can't buy it. 

Even if these bearings are as great as they say, why isn't everyone using them? Did they invent them? Where's their patent? Surely they could make a fortune selling them. I mean they've potentially just reduced the automotive world's carbon footprint by say 10% (assuming that a RWD version would only lose 5%), whilst massively boosting the profits of haulage companies, taxi firms, bus companies, airlines (think gas turbines) and train operators, AND hugely pissed off Jason and his oil company buddies. They'd have a monopoly on the entire world's bearing trade.


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## thistle (Oct 27, 2007)

I think you need a new calculator.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> I think you need a new calculator.


Why would that be?


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## thistle (Oct 27, 2007)

P = Fv = 0.5 * 0.5645 * 1.225 * (86.67^3) = 225100 ?


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## cleethorpes (Sep 30, 2008)




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## obzi (Feb 19, 2008)

I so wish I understood what you guys were talking about.lol


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## charles charlie (May 3, 2008)

@ Cleethorpes...

I bet you were the kid at the back of the class who threw soggies at the nerdy kids, eh?!


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## cleethorpes (Sep 30, 2008)

I think it's fair to say that this ' battle ' is getting ridiculous..


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## Burning (Mar 11, 2009)

David.Yu said:


> The one thing I really can't believe, is the quoted 10% transmission loss. For a rear transaxle 4WD DCT set up? How can that possibly be more efficient than a conventional 2WD manual set up?


An American magazine compared the GT-R with a 997TT on a dyno and the output was similar.



R33_GTS-t said:


> Just like the torque curve was completely flat from 3200-5200rpm a la the graphs in the brochure?


It's an approximation.



R33_GTS-t said:


> 195mph
> YouTube - 2009 Nissan GT-R Top Speed TEST 2


Considering they're the only ones to have exceeded 193mph (that I know of) without increasing the redline I'll take that report with a grain of salt.

Now let's take a look at your dyno numbers :
-On the first sheet the torque curve and the power curve don't cross at the same rpm when they should. Also it's one of the first dyno of the HKS GT570 kit and you now SPE just happens to resale it. Strangely enough since then they've lost their magical American touch http://www.nagtroc.org/forums/index.php?s=&showtopic=27822&view=findpost&p=391733 "only" 26% increase on 91oct.
-The second sheet "only" give an increase of 27% with the smoothing on. http://www.nagtroc.org/forums/index.php?s=&showtopic=29373&view=findpost&p=408918


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> P = Fv = 0.5 * 0.5645 * 1.225 * (86.67^3) = 225100 ?


225100 Watts = 225.1kW = 302hp 

Always one step ahead.


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## R33_GTS-t (Apr 27, 2005)

Burning said:


> Considering they're the only ones to have exceeded 193mph (that I know of) without increasing the redline I'll take that report with a grain of salt.


You shouldn't, it's bad for your blood pressure.



Burning said:


> Now let's take a look at your dyno numbers :
> -On the first sheet the torque curve and the power curve don't cross at the same rpm when they should.


That's because they're on 2 different scales (and so don't cross at 5252rpm) that aren't proportional to each other (so both plots don't cross at the same rpm). E.g. 576/536 does not equal 397/316.



Burning said:


> Also it's one of the first dyno of the HKS GT570 kit and you now SPE just happens to resale it. Strangely enough since then they've lost their magical American touch http://www.nagtroc.org/forums/index.php?s=&showtopic=27822&view=findpost&p=391733 "only" 26% increase on 91oct.
> -The second sheet "only" give an increase of 27% with the smoothing on. http://www.nagtroc.org/forums/index.php?s=&showtopic=29373&view=findpost&p=408918


This proves my argument not yours. 512hp + 27% gain is 650hp.


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## thistle (Oct 27, 2007)

R33_GTS-t said:


> 225100 Watts = 225.1kW = 302hp
> 
> Always one step ahead.


Thanks for explaining that your units. I agree with your calculation based on P=0.5*CdA*density*speed^3.

How about adding rolling resistance? Since we're in metric (and I'm polite so I'll explain my working, assumptions, units rather than presenting a jumble of figures  ), I'm adding 50kg fuel and an 80kg driver to the quoted kerb weight and assuming the upper end of Crr because these are not low rolling resistance tyres and they are quite wide:

P=FV=m.g.Crr.V=1870*9.81*0.035*86.67=55.6kW=75 HP

(P=power(W), F=force(N), m=mass(kg), Crr=rolling resistance coefficient, g=gravity(m/s^2), V=velocity(m/s))

So we have a total of 377 WHP for 193mph with the assumptions given. Whilst this is getting very near to a 380 WHP dyno dynamics, it is indeed short of even Nissan's quoted flywheel power if the losses are only 10% (which would be 0.9*473=426 WHP).

Why though would this support the car needing more power than Nissan quote when the 996 Turbo with 414 HP also does well with top speed (190mph). CdA (in imperial units) for a 996 Carerra is 6.27, turbo would be a bit higher. GTR is 6.08.

But again, stock and modified Porsches can read silly numbers on rolling roads, although the cooling hampers them even more than the GTR on chassis dynos.


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## thistle (Oct 27, 2007)

cleethorpes, you're not really contributing much here, it is quite an interesting discussion I think, with some important issues. I've had to brush up on my aerodynamics to keep up with R33, although I'm not sure I'd agree he is "always" one step ahead 

I would say it is nice to finally have a car that doesn't have the aero of a brick like my previous rice rockets  It makes power worthwhile.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> Thanks for explaining that your units. I agree with your calculation based on P=0.5*CdA*density*speed^3.
> 
> How about adding rolling resistance? Since we're in metric (and I'm polite so I'll explain my working, assumptions, units rather than presenting a jumble of figures  ), I'm adding 50kg fuel and an 80kg driver to the quoted kerb weight and assuming the upper end of Crr because these are not low rolling resistance tyres and they are quite wide:
> 
> ...


You're assuming that the normal force is equal to the weight. At 120mph, the GTR generates 80kg (176lbs) per end.

Porsche still contends GT-R 'ring lap times phony - NAGTROC - The Nissan GT-R Owners Club

This would take your 1870kg figure up to nearly 2030kg, giving about 89hp for rolling resistance. But with Df=0.5*Cdf*p*v^2, downforce at 195mph would be 176kg. So weight goes to 2046kg and hence 90bhp.

However, here's where the problem lies. Sport Auto measured the GTR's Cd at 0.31 not 0.27.

MWerks Forums: REPORT: Corvette ZR1 matches Nissan GT-R around Nürburgring in Sport Auto test

And I can understand why. You can't produce 176kgf or 1727N of downforce without introducing more drag as the tip vortices will drag the local airflow upward and hence the downforce vector will tilt backwards. I'm going to assume that a third as much force points back - 500N. So P=Fv = 500*86.67 = 43335W = 58hp

Quick check

Drag = 0.5*1.225*0.5645*86.67^2 = 2597N with Cd=0.27 so with Sport Auto's 0.31 measured that becomes 2981N, which suggests 384N of extra drag but if only we knew what speed they measured that 0.31 at. Doubtful 195mph and remember that both downforce and hence drag and Cd increase at higher speeds. Anyway that equates to 45hp. 

Using the higher figure we get 302+90=58=450hp. Using the lower measured figure, which we don't know the speed for, we get 302+90+45=437hp.

Even with a mythical 10% loss you're looking at an absolute minimum of 486hp and potentially 500hp.

This of course assumes that you hit peak speed at exactly peak power. The GTR peaks at around 6300-6400rpm and tails off more significantly after 6700rpm looking at plots. 195mph is hit at ~7000rpm, where power is down ~5% on peak. Therefore power with 10% loss must equal 526hp (500/0.95) or at least 512hp (486/0.95). Using a more realistic 15% loss. 526 -> 558 (450/(0.85*0.95)) and 512 -> 541 (437/(0.85*0.95))

This confirms my gut instinct that power is somewhere between 512 and 558hp. Next time we'll just go with my gut and save a thread eh?


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## thistle (Oct 27, 2007)

You can quote Dynojet and Mustang figures all day and use them as self fulfilling prophecies, but the dynos graphs I most frequently come across that have run R35s in the UK/Europe are Dyno Dynamics and Maha and the numbers even when the same stock or staged maps are used (on similar quality fuel - backed up by similar knock retard results) are completely different to Dynojet and Mustang. It is interesting that a nice road dyno utility posted on Evolutionm.net for Evos has rather different "multipliers" to correct figures to various dynos. This is why when we're discussing a car sold in the UK (as was the original topic of this thread), or cars that we're tuning mainly in the UK, we'll use the more conservative figures people are likely to get here. Otherwise, it causes quite a lot of problems when people run their American tune on Maha in Europe and fall well short of expectation.

You can massage the top speed up (nice since you can then cube it LOL) and the peak power down, but you're still struggling to get the power up in a way that I find convincing.

Meanwhile, the top speed of other cars with less power and greater CdA is nearby, injector size and duty cycle with sensible BSFC support less power, as do Nissan's claims and most UK dyno results. There is little point being UK based in me trying to get these US dyno figures as it won't happen on the same spec of car, on equivalent fuel and the same maps. It is interesting to see their deltas, although as discussed they can be troubled with bias too.

So I see absolutely no reason at all to validate your gut instinct.


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## Burning (Mar 11, 2009)

R33_GTS-t said:


> This proves my argument not yours. 512hp + 27% gain is 650hp.


And where does that come from ? Let me guess out of your ass ? Last time I checked the gt-r had arround 480hp. Also note that a stock gtr baseline between 380 and 400 whp on a well calibrated dyno add a 20% drivetrain loss and it's not hard to "believe" Nissan on their quoted figure.
Anyway this is pointless dyno are tuning tools nothing more nothing less.


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## R33_GTS-t (Apr 27, 2005)

thistle said:


> You can quote Dynojet and Mustang figures all day and use them as self fulfilling prophecies, but the dynos graphs I most frequently come across that have run R35s in the UK/Europe are Dyno Dynamics and Maha and the numbers even when the same stock or staged maps are used (on similar quality fuel - backed up by similar knock retard results) are completely different to Dynojet and Mustang. It is interesting that a nice road dyno utility posted on Evolutionm.net for Evos has rather different "multipliers" to correct figures to various dynos. This is why when we're discussing a car sold in the UK (as was the original topic of this thread), or cars that we're tuning mainly in the UK, we'll use the more conservative figures people are likely to get here. Otherwise, it causes quite a lot of problems when people run their American tune on Maha in Europe and fall well short of expectation.
> 
> You can massage the top speed up (nice since you can then cube it LOL) and the peak power down, but you're still struggling to get the power up in a way that I find convincing.


The top speed hasn't been massaged up. 195mph is a tried and tested figure. 0.31 is also a measured actual Cd (Sport Auto) allowing for downforce effects (at what speed, we'll never know). It's also a fact that peak speed isn't reached at peak power in the GTR's case. Evo have also tested GTRs at a value corresponding to the lower calculated figure on a dyno that reads fairly accurately, even slightly pessimistically, against most manufacturer's claims (even though they probably send their best car along).

We've already discussed the Maha rolling road. We've seen that losses vary between *full power* and full load and full power and no load in conventional gearboxes by 20-50%. However, what the Maha is actually measuring is a rundown loss under no power and uniform load. It therefore can't possibly be correct as a full power-full load figure but many tuners like it because it gives them a feeling of conservatism, 'not like all the tuners trying to boost power figures'. It wouldn't actually surprise me if this is how Nissan arrived at the 10% figure.



Burning said:


> And where does that come from ? Let me guess out of your ass ?


Actually it came out of a test performed by Evo on a dyno that's consistently either accurate or slightly pessimistic against manufacturer figures and since the whole point of a flywheel figures is to compare against such manufacturer's figures, it seems like a good place to start.

And no need to get in a strop just because your logic is flawed.



Burning said:


> Last time I checked the gt-r had arround 480hp.


Yeah hur. Where did you check that then? The brochure?



Burning said:


> Also note that a stock gtr baseline between 380 and 400 whp on a well calibrated dyno add a 20% drivetrain loss and it's not hard to "believe" Nissan on their quoted figure.


Unless you believe their 10% loss figure as well, in which case the car would have about the same flywheel hp as an Audi RS4.



Burning said:


> Anyway this is pointless dyno are tuning tools nothing more nothing less.


They're comparison tools and what we're trying to do is get a figure we can compare against other cars.


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## ScottyB (Jun 9, 2009)

R33_GTS-t said:


> They're comparison tools and what we're trying to do is get a figure we can compare against other cars.


I have been following this thread with great interest and wanted to chip in with my 50 pence worth.

Dyno's are only comparison tools if and when you have a proper scientific control over the test/comparison call it what you want which is impossible.

Different dynos read differently, some runs are even carried out differently, e.g. Dastek being a slower run up.

You could guarantee you could take the same car to 2 identical makes of dynos and the numbers would vary - fact!

In my case i used a Dyno Dynamics as a baseline starting point - i was not overly fussy as to what the actual figures came out as i just wanted to capture them.

Once we had made changes to the car, e.g. hardware in the form of a full Ti race exhaust and Y Pipe and then Cobb i wanted to capture the figure again to show percentage improvement on the same dyno.

Even this method is flawed, we cannot guarantee that both the car temps and ambient temps will be exactly the same as the before run even on the same dyno.

Add in different dynos, different countries, different fudge factors and you may as well be trying to compare eggs with custard.

Sorry to be blunt but who really gives a toss about what the actual numbers come out at? Apart from the sad boy racers down the boozer, BHP in particular is pub talk, even my 9 year old son knows "torque turns wheels" and BHP is like trying to show who has the biggest dick!

I prefer to see and experience real life live mapping where the car is getting the correct amount of air flow and load characteristics as it will do on a daily basis.

I used to be young and naive and think that i needed a 450 BHP car to beat such and such.

I now prefer instead to use the likes of my race logic and live mapping to capture real life improvements, half a second here, a few hundreths there all related to real life driving scenarios where it really counts both on the road and track.

Sure i will put her back on the Dyno every now and again to overlay the graphs for my own interest but other than that Dynos in my opinion are to be used as a baseline tool and percentage increase/improvement nothing more nothing less.

If you are trying to compare different cars on different dynos to see how they stack up to each other, then you had better be working for NASA becuase you will need a team of experts to work that mess out.......do me a favour and crack time travel for me while you are at it, in fact that will probably be easier!


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## David.Yu (Jun 28, 2001)

ScottyB said:


> I have been following this thread with great interest and wanted to chip in with my 50 pence worth.
> 
> Dyno's are only comparison tools if and when you have a proper scientific control over the test/comparison call it what you want which is impossible.
> 
> ...


Hear, hear. What I have been saying all along.

Just out of curiosity, what were your before and after figures on that DD rolling road? Flywheel and AWHP if you have them?


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## Burning (Mar 11, 2009)

R33_GTS-t said:


> Actually it came out of a test performed by Evo on a dyno that's consistently either accurate or slightly pessimistic against manufacturer figures and since the whole point of a flywheel figures is to compare against such manufacturer's figures, it seems like a good place to start.
> 
> And no need to get in a strop just because your logic is flawed.


So let me guess everyone should assume when a tuner quote them a power rating a the crank that it was on a baseline of 512hp ? is that it ?




R33_GTS-t said:


> Yeah hur. Where did you check that then? The brochure?







R33_GTS-t said:


> Unless you believe their 10% loss figure as well, in which case the car would have about the same flywheel hp as an Audi RS4.


Even cars with RMR layout can barely attain that 10% figure. It's impossible for a GT-R and I'm pretty sure you won't be able to find that magical 10% drivetrain loss on anything official.



R33_GTS-t said:


> They're comparison tools and what we're trying to do is get a figure we can compare against other cars.


If all dyno were the same and all pull done in the same atmospheric conditions that argument would be valid.
2009 Nissan GT-R: True Power From the Dyno In comparison to a 997 turbo
2009 Nissan GT-R Horsepower: The Truth - Nissan GT-R Dyno Run - Motor Trend On a dyno that calculate drivetrain loss. I'll take it with a grain of salt considering I'm not sure how it does it but with 100 hp dissipated at the redline that put the baseline at 385whp.


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## thistle (Oct 27, 2007)

I agree ScottyB.



> We've seen that losses vary between full power and full load and full power and no load in conventional gearboxes by 20-50%.


The only decent empirical data you produced showed 1.4% of the total power being lost in an experimental single gear setup at too low RPM to be useful.


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## ScottyB (Jun 9, 2009)

David.Yu said:


> Hear, hear. What I have been saying all along.
> 
> Just out of curiosity, what were your before and after figures on that DD rolling road? Flywheel and AWHP if you have them?


Hi David,

It was my car's graph Thistle posted on the first page of this thread - http://www.gtr.co.uk/forum/attachments/3322d1250071532-dyno-results-quarter-mile-time-dyno.jpg

479.4 Before
533.2 After

Both i believe Flywheel figures tested at a local DD Unit on the same day(Hypertech in Bonnybridge)

I have not been back on since instead prefering to concentrate on the Race Logic (Thanks for the heads up on that) and live mapping

Regards

ScottyB


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## Rich-GT (Apr 2, 2008)

OK I have managed to stay out of this thread, and have lost track as to whether the key problem is does the car in the first post make 650 BHP or doea the standard car make 480 BHP?

What I will say is that when David & I had our cars Dyno'd on the Dyno Dynamics at Surrey RR my standard car made 401HP at the wheels. This may even be the same RR that R33 is refering to as being used by Evo and providing a good comparison with manufacturers figures?

Anyway 401HP at the wheels needs to have 20%, which is quite reasonable, added to it to get to 480HP, so my feeling is that the only reason people keep talking about 10% is because of a load of optimistic dyno's, be they in the UK or the US?


Rich


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## David.Yu (Jun 28, 2001)

Rich-GT said:


> OK I have managed to stay out of this thread, and have lost track as to whether the key problem is does the car in the first post make 650 BHP or doea the standard car make 480 BHP?
> 
> What I will say is that when David & I had our cars Dyno'd on the Dyno Dynamics at Surrey RR my standard car made 401HP at the wheels. This may even be the same RR that R33 is refering to as being used by Evo and providing a good comparison with manufacturers figures?
> 
> ...


Tut tut Rich! I was trying to keep your name out of it, but as you've admitted it... 

401awhp divided by 0.8 (for 20% loss) = 501hp at the flywheel.
Surrey Rolling Road's DD used slightly more than 20% as their loss figure which interestingly appears to differ from Scotty B's DD...

All goes to show it's all ballox. (Apart from, maybe, showing increases/changes.)


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## thistle (Oct 27, 2007)

Some dynos seem to have large losses either calcuated or coastdown applied to their figures to get flywheel estimates, the losses on dynos include all sorts of other losses that there are not when a car is on tarmac. Has anyone noticed the huge losses that Powerstation's MAHA dyno has? But it still produces sensible flywheel estimates and for years has been a place to give you back down to earth figures.


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## Rich-GT (Apr 2, 2008)

David.Yu said:


> Tut tut Rich! I was trying to keep your name out of it, but as you've admitted it...


Yes, but I have admitted to so much since the RR run, it is now of little matter.  You are right 20% added is not the same as 20% taken away  however to get from 485 to 401 is still about a 17.5% loss, which although low in conventional 4WD drive terms is still a lot more than 10%. 


Rich


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## R33_GTS-t (Apr 27, 2005)

ScottyB said:


> Sorry to be blunt but who really gives a toss about what the actual numbers come out at? Apart from the sad boy racers down the boozer, BHP in particular is pub talk, even my 9 year old son knows "torque turns wheels" and BHP is like trying to show who has the biggest dick!


Not this old argument again. More power at the flywheel means more torque at the wheels for any given transmission setup. That's why you shift with engine power, not engine torque. It's the spread of power in the utilised part of the rev range that counts. Higher power in that section is better than higher torque, though obviously higher torque at the same rpm would mean more power.



Burning said:


> So let me guess everyone should assume when a tuner quote them a power rating a the crank that it was on a baseline of 512hp ? is that it ?


If they were trying to gain a rough idea of actual flywheel hp it's not a bad place to start.



Burning said:


>


Well you despise dynos, yet utterly back a figure of 480 that couldn't have come from anywhere else and is probably cack anyway. You've got to see the paradox in that.



Burning said:


> Even cars with RMR layout can barely attain that 10% figure. It's impossible for a GT-R and I'm pretty sure you won't be able to find that magical 10% drivetrain loss on anything official.


Good, we can agree on that, but others in this conversation do not. The 10% figure was probably measured on a Maha style rolling road that measures the work being done by the transmission to drag the speed down under no load and no power conditions. Completely unrealistic.



Burning said:


> If all dyno were the same and all pull done in the same atmospheric conditions that argument would be valid.
> 2009 Nissan GT-R: True Power From the Dyno In comparison to a 997 turbo


Different times and most importantly different gears. 4th is known to have less losses than 3rd for very obvious reasons.



> It's not an easy deal. All Japan-spec cars are equipped with a top-speed limiter at 180 km/h (112 mph) and we keep banging into it when we use 4th gear in the GT-R. *Finally we select 3rd gear *and get some clean pulls.
> 
> When the computer finishes crunching the numbers, the data tells us that the 2009 Nissan GT-R is putting out 406 hp at 6,400 rpm and 414 lb-ft of torque at 3,800 rpm. Once you factor in the parasitic losses of the all-wheel-drive system, these numbers are wholly in line with Nissan's claim for the engine's power at the crankshaft. During one pull, the horsepower perked up to 414 hp, but it wasn't repeatable and torque production through the midrange suffered.
> 
> *Earlier*, Harman tested a 997-generation Porsche 911 Turbo on the same dyno


AND, nobody ever said 997TTs were exactly shy on power:
Powertrain Performance Graph for Porsche 911 Turbo Cabriolet -07 (353 kW)

A 3% transmission power loss and zero torque loss.:chuckle: Actually I lie, on closer inspection there is a 0.5% torque gain in the transmission.
Powertrain Performance Graph for Porsche 911 Turbo Cabriolet -07 (353 kW)

Compare that with other AWD car losses on the same dyno:
Powertrain Performance Graphs - Rototest Research Institute

So the GTR produces a slightly higher reading in 3rd than a 997TT in 4th, even though the 997 is underquoted too.



Burning said:


> 2009 Nissan GT-R Horsepower: The Truth - Nissan GT-R Dyno Run - Motor Trend On a dyno that calculate drivetrain loss. I'll take it with a grain of salt considering I'm not sure how it does it but with 100 hp dissipated at the redline that put the baseline at 385whp.


That was the amazing 10% loss calculating dyno. The full article isn't there. The wheel figure measured was about 435whp and the dyno measures the work done by the transmission under no power and load in dragging the speed down. Wholly unrealistic. The full article is linked earlier in this thread by Mindlessoath.



ScottyB said:


> http://www.gtr.co.uk/forum/attachments/3322d1250071532-dyno-results-quarter-mile-time-dyno.jpg


Not being funny here but your plot does show a higher torqueower ratio than most plots. Could it be that the dyno suffers from bad drag at higher speeds?



thistle said:


> Some dynos seem to have large losses either calcuated or coastdown applied to their figures to get flywheel estimates, the losses on dynos include all sorts of other losses that there are not when a car is on tarmac. Has anyone noticed the huge losses that Powerstation's MAHA dyno has? But it still produces sensible flywheel estimates and for years has been a place to give you back down to earth figures.


There's the loss of the dyno itself and I guess power doesn't transmit as well from rubber to metal rollers as it does to asphalt.


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## R33_GTS-t (Apr 27, 2005)

Just as a little aside, since many are more into times than dynos, I found the quickest stock turbo GTR - [email protected] - and the fastest - [email protected] - and plugged the numbers in here allowing for a weight of 1738kg + a 200lb driver (4024lbs):

Quickest 671hp est.
Horsepower Calculator from 1/4 mile ET and Trap Speed - DragTimes.com

Fastest - 692hp est.
Horsepower Calculator from 1/4 mile ET and Trap Speed - DragTimes.com

Make an allowance for DCT but even then the case is made. I also compared these estimates with wheel figures and the loss comes to around 18%.


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## Rich-GT (Apr 2, 2008)

very happy with 18%  as that is exactly what my standard car needs to get from the 401HP measured @ the wheels to 485 @ the engine.

Interesting numbers from the dragtimes calculator.

My best in the standard car.
11.757 @ 118.5 MPH which gives 506HP, so high / plauseable?

My best with just a Cobb / GTC 99RON map, no hardware changes.
11.0531 @ 124.79 MPH which gives 599HP, another 93HP seems a bit high to me, but who knows perhaps we really have gained that much?? 


Rich


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## thistle (Oct 27, 2007)

Those calculators don't work well for UK dynos or for dual clutch gearboxes. I don't know how you can think the stock turbos can do nearly 700 BHP and keep a straight face.

Rich, the same map on ScottyB's car did 527 BHP when standard.

And Rich, as much as I would like to say that the map made 0.7s and 6.3mph, I don't believe it did, your second figures were with more practice on a better surface were they not?


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## David.Yu (Jun 28, 2001)

Yes we cannot compare Vbox/Cobb logged 1/4 mile times on the road with drag strip times.

A) there is a massive difference in surface
B) drag strips use rollout which makes a big difference


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## Rich-GT (Apr 2, 2008)

thistle said:


> And Rich, as much as I would like to say that the map made 0.7s and 6.3mph, I don't believe it did, your second figures were with more practice on a better surface were they not?


Of course there is some time / temp/ conditions/ experience variability, but to a first approximation I would say that the gain is real.  60Ft's were 1.88 v 1.75 but you must expect improvement with more power.

These are just examples of my best time in standard form and best time with the 99RON map, however I have *lots* of other data including a lot of Performance Box data that shows similar gains. 

Also although what David says about comparing Drag Strip and Road based Performance Box data is correct, if the PB is set up to record times allowing for the 1 Ft rollout then you get results very close to the Drag Strip times.

As an example my slip for the 11.0531 run showed 11.1 on the PB, it only does 1dp. The 60ft on the slip was 1.7525, PB 1.8. Where there is a big difference is in the terminal speed because the Drag Strip measures over a distance wheras the PB is at the 1/4 Mile, So the slip shows 124.79 & the PB 127MPH.

Does anyone know what distance the Drag Strip beams at the finish line are apart? Looking at the difference in speeds indicates a wopping 200Ft or so?

Roll out does make a tremendous difference, I would say as much as 0.3 second, I reckon you are doing between 4 & 5 MPH when you break the beam. I am doing some analysis at the moment comparing Launch Techniques, will share when I am confident in my findings,  although I may hold a little back. 


Rich


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## mindlessoath (Nov 30, 2007)

unless you pull out the engine and dyno it you wont get the real figure. this is a dual clutch trans with low friction bearings. simple as that. its design is to reduce the friction loss. and for those who dont belive it, its all in the laptimes. nissan has made this car to put power to the ground and not waste it. thats how it can do such fast times with lower horse power and higher weight.

read this article GTRCenter » Blog Archive » Thank you, Porsche AG!
porsche basically is going the same way now. high weight, low friction and dual clutch trans but good laptimes.

This is because it utilizes all the power it can unlike traditional hardware. your going to have to evolve with the rest of us. its relitivly new and its catching on with everyone soon.


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## R33_GTS-t (Apr 27, 2005)

Rich-GT said:


> very happy with 18%  as that is exactly what my standard car needs to get from the 401HP measured @ the wheels to 485 @ the engine.


That was for a 605whp and 610whp car on a Mustang dyno. On a dyno dynamics dyno the power loss may be a higher percent, particularly at lower powers since not all loss sources are proportional to power.



Rich-GT said:


> Interesting numbers from the dragtimes calculator.
> 
> My best in the standard car.
> 11.757 @ 118.5 MPH which gives 506HP, so high / plauseable?


Wasn't that exactly what your car made on the Evo dyno? I think the DCT makes the car use its power more efficiently but then that's counteracted somewhat by the limp-wristed 2500rpm launch control system.



Rich-GT said:


> My best with just a Cobb / GTC 99RON map, no hardware changes.
> 11.0531 @ 124.79 MPH which gives 599HP, another 93HP seems a bit high to me, but who knows perhaps we really have gained that much??
> 
> 
> Rich


Why mate? If at 0.7bar stock the car's making about 506hp, that's at 1.7bar total pressure (including atmospheric), so in theory each 0.1bar of total pressure is giving 30hp. Obviously at higher boost there's more heat, both down to inefficiencies and basic isentropic compression laws, so the density increase isn't 1:1 with the pressure increase. But you've also had mapping to improve power and I'm guessing you're at 1.1bar, so why is 599hp unrealistic?

If you put in some typical quarter times for a Z06 into that calculator you'll see that it's pretty miserly. A Z06 is 1420kg (3124lbs) + 200lb driver = 3324lbs. Try [email protected] for example.

The calculator works the trap speed as well as just times and weight so it's not reading low just due to the lack of AWD on a ZO6.


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## thistle (Oct 27, 2007)

At about peak power, there is 0.2 bar between stock and Rich's previous map about which the figures are being discussed. There is about 0.3 bar between stock and his present map.

93 BHP from 0.2 bar is just not realistic with no other changes apart from a few degrees of timing and leaning it out. Leaning it and adding the timing might just keep up the efficiency to your 30 BHP/0.1 bar.

I hate overstating things, I would rather users were satisfied or had a pleasant surprise.

However, I'm used to all sorts of claims about how it now purrs better, has better economy at cruise, there's loads of placebo going on this game. I just smile and nod politely, but know I didn't do anything to do those things!


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## R33_GTS-t (Apr 27, 2005)

Have you got the boost plots together with the power graphs and AFR? Just interested.


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## thistle (Oct 27, 2007)

Dyno didn't include a boost plot. But there is one here with the car's wideband (which reads 0.5 leaner than reality) here showing stock vs stage 2 on a standard car (mine) like Rich's.

http://www.gtr.co.uk/forum/122041-accessport-datalogging.html


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## R33_GTS-t (Apr 27, 2005)

Looks like there's a variance of points around peak power with the Cobb AP, with some at 1bar and some at 0.9bar. The stock system runs more consistently at 0.7bar, so the difference on a quarter run could be 0.3 or 0.2bar. Interesting though.:thumbsup:


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## thistle (Oct 27, 2007)

That standard log was much shorter with just a few pulls through a gear or two. The stage 2 plot had a more comprehensive workout so there is more use of different gears. It is the lower gears which manage to hold about 1.0 bar at 6000 RPM on stage 2 (and to 7000 RPM with new boost control methods). Peak power is over a wider area when they are tuned which does allow possibly appropriate short shifting in the higher gears where the ratios suit this and more average power, which could improve the times. With the wastegate solenoid at 100% duty from 6000 upwards, you can just get it to hold 1.0 bar at 7000 RPM in the lower gears, but in 4th it drops away to c.0.95. With actuators you can get it to show more boost and airflow, but I've not had the opportunity to tune one with injectors also. Because the stock injectors go lean I don't want to run them with actuators running any more top end boost than stock actuators, which makes actuators a bit pointless as it is an engine out job, and it would be disappointing if like AMS you fit actuators and injectors and get no more power... It may be that with the correct AFR from bigger injectors it is possible to make use of extra airflow with good ignition timing without knock, but the jury is out. Results are conflicting, and it is difficult to prove either way on a dyno because it may give you pessimistic ignition timing. On the other hand, some dynos have very little load and a quick run up, so may if you got it just right be able to even hold a bit more boost as there isn't time for the turbine to slow down like in 2nd and 3rd gear on the road.

On the same strip on the same day (sorry I don't have terminals), a car with stock fuel pumps, stock fuel pressure, stock actuators, uprated intercooler & pipes, full exhaust, was running 0.2 seconds quicker than another car with I gather had the HKS GT600 pack which has uprated fuel pumps, raised fuel pressure, actuators, intercooler pipework with stock intercooler, full exhaust, boost controller, induction, blow off valves. The logs I've had from this kit look a bit rich, but the knock is sensible because the stock ignition map isn't too bad. Intake valve timing doesn't add to drag performance I think. Who knows if when optimised it does really good times? There are some fantabulous looking dyno plots with all this kit and a custom tune, but others seem disappointed.

I think it is probably in dimishing returns territory, and some (GTR aftermarket turbo sellers) are reporting that thrust bearings on the stock turbos are showing excessive wear when used at high boost. Extra top end boost may just be overspeed and hot air.

You mentioned the turbos were the same as on the Subaru, I know they are made by IHI, is there a VF model number that I would recognise from the Subaru, do you have any wheel measurements etc?


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## Burning (Mar 11, 2009)

R33_GTS-t said:


> Well you despise dynos, yet utterly back a figure of 480 that couldn't have come from anywhere else and is probably cack anyway. You've got to see the paradox in that.


I don't despise dyno they're good tuning tool. What I despise is big number from tuned cars without a baseline done in the same condition on the same dyno for comparison.



R33_GTS-t said:


> AND, nobody ever said 997TTs were exactly shy on power:
> Powertrain Performance Graph for Porsche 911 Turbo Cabriolet -07 (353 kW)
> 
> A 3% transmission power loss and zero torque loss.:chuckle: Actually I lie, on closer inspection there is a 0.5% torque gain in the transmission.
> ...


Well then you can't blame Nissan from making more than claimed and that as nothing to do with the gentleman's agreement IF of course the 997TT is making more than claimed.



R33_GTS-t said:


> That was the amazing 10% loss calculating dyno. The full article isn't there. The wheel figure measured was about 435whp and the dyno measures the work done by the transmission under no power and load in dragging the speed down. Wholly unrealistic. The full article is linked earlier in this thread by Mindlessoath.


I don't understand. How is 90hp lost equal to 10% drivetrain loss ? No matter how you look at it that's around 20%. I'm speaking about this image :


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## R33_GTS-t (Apr 27, 2005)

Burning said:


> I don't understand. How is 90hp lost equal to 10% drivetrain loss ? No matter how you look at it that's around 20%.


Read the full thread. The rolling road in that article measured 10% loss on rundown. They made 430ish at the wheels. It's not stated it the article you referenced but in the full article it is. This dyno has measured a bullshit loss because neither power nor load is present as it measures the loss.
http://www.motortrend.com/features/performance/112_0812_2009_nissan_gt_r_dyno_test/index.html


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