# So what mods DO you need for 4.25 performance?



## dudersvr (May 7, 2003)

Notice I did not say to be 4.25 because we all know what packages are offered.
After a few opinions Ill surprise youopcorn:


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## Imran (May 6, 2017)

Downpipes,
y pipe (not sure if a full exhaust is required)
Induction kit
Injectors (maybe fuel pumps).


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## dudersvr (May 7, 2003)

Imran said:


> Downpipes,
> y pipe (not sure if a full exhaust is required)
> Induction kit
> Injectors (maybe fuel pumps).


That is the accepted formula yes.


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## Stealth69 (Jan 6, 2005)

Injectors, speed density kit and a remap.... possibly a Y-pipe probably not tho.as the y-pipe is less restrictive than the downpipes


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## charles charlie (May 3, 2008)

1050/1000 injectors
decatted
Stock intakes with uprated MAF or SD tune
Wider bore exhaust (although Ryan at 2Bar reckoned the stock rear section was adequate to 750 bhp before back pressure became an issue).


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## Skint (Oct 11, 2014)

750cc injectors,map,decat


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## simGTR (Aug 5, 2017)

Are we talking identical headline figure, characteristics, or both.

To get the same response I think you'd need downpipes, but could get away with stock Y-pipe and zorst.

Maybe a bigger FPR instead of injectors.

And a remap, stock filters.


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## Evo9lution (Aug 24, 2013)

What do you mean by performance? Track times? Drag times? Response? Power & torque?

If you're talking the quarter mile, maybe drag radials, y-pipe with a sports cat & a remap?


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## terry lloyd (Feb 12, 2014)

N2O


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## Stealth69 (Jan 6, 2005)

terry lloyd said:


> NO2


A number 2? eugh I pity the person that bought your motor


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## terry lloyd (Feb 12, 2014)

Stealth69 said:


> A number 2? eugh I pity the person that bought your motor


Ha -was a long night


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## kindai (Feb 8, 2016)

dudersvr said:


> That is the accepted formula yes.


Im running 660-670hp on stock downpipes.

Have the 1050cc ansus, can probably drop those down realistically.


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## Skint (Oct 11, 2014)

How long do we have to wait then for a answer?


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## dudersvr (May 7, 2003)

Well guys thanks for chipping in. Heres what we found when we were asked to cut corners due to finances and incorrect parts.
Customer brought car in with a nasty vibration (with car stationary), we isolated to the engine and I made the decision it was the transfer plate/ bell housing (bell housing had a decent amount of play). He was on a strict budget having spent out on other parts of the car but after calling and saying 'Hey as downpipes have to come off to swap housings can we put downpipes back on? Yes we say but may need remap (he had a stage 1 so had ecutek licence) so he sources some very cheap downpipes from Ebay (needs must etc) then a while later another call how much to fit injectors and do we have any used ones? So he is told price and as luck would have it we had an almost new set from a customers car and it was someone he knew, he strikes a deal where he can pay for them later in the month, then he does the same with air intakes.

So we change plate and housing and fit downpipes, they done fit his custom y pipe as it has no flexi section and the are 10mm out either side, likewise the air intakes are too big and have the wrong reducers as they came off a bigger power car with big stock location turbos. So we call him and he is slightly deflated as he is looking forward to a quicker car with a very bargain 4.25 conversion. What can we do he asks, the only thing I can do is knock the cats out of his stock pipes, what about the stock air boxes? They will have to stay he is told, you can add intake kit later and if the map needs a tweak then we can do that.

So he now has 1050 injectors, stock air boxes and filters, stock downpipes with the cats knocked out and our map which is speed density (all our maps are). A test drive revealed it to be very strong and in no way feeling slower than a 'proper' 4.25. He goes out on a meet and has pulls next to 4 other 'proper' 4.25 cars and depending on length of pull either sits level or pulls on all of them.

Now the proof of the pudding is in a time ticket, pulls on road are fine but down to driver etc, dynos are fine but all read different and can be fudged. The one irrefutable thing to prove power is the terminal speed in a 1/4 mile, it matters not how the car leaves the line it will always be pretty accurate and a very good indication of power. The fastest 4.25 ive seen is Ray McNallys teal blue car that run the pod all the time, his terminals are always 126/7 and may have hit 128. This car ran 4 times, I have a pic of 2 runs and he is adamant the car did 130 on one of the other runs but only can find this ticket 








So for a set of injectors and a little labour plus map you can have the same performance as a £4700 stage 4.25 conversion, the car was fully datalogged and all parameters found to be spot on even with some decent pulls in very hot ambient temps. Beauty is you dont even need to remove downpipes to get the cats out so no risk of snapping turbo studs and having to remove the engine. Go figure !!!!:squintdan


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## dudersvr (May 7, 2003)

Skint said:


> How long do we have to wait then for a answer?


4 mins :double-finger:


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## Skint (Oct 11, 2014)

Bhp?
Lb/ft?


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## Stealth69 (Jan 6, 2005)

I wasn't far off then  what do I Win? lol


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## dudersvr (May 7, 2003)

terry lloyd said:


> N2O


With Nitrous a stock engine, turbo, intake, intercooler car ran 9.2 @ 147mph

:chuckle::chuckle::chuckle::chuckle:


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## dudersvr (May 7, 2003)

Skint said:


> Bhp?
> Lb/ft?


Who cares? We have asked him to come and put car on the dyno to get accurate figures and a little more power as dimitri wont go further until he can see exactly where the torque is, we know from similar maps it will be around 625 ft lbs and the last 2 4.25 cars on the dyno made just over 700hp with 100-200 kmh times to prove it.


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## dudersvr (May 7, 2003)

Stealth69 said:


> I wasn't far off then  what do I Win? lol


I will think about that one :chuckle::chuckle:


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## dudersvr (May 7, 2003)

Stage 4.25 car with SD map on SRD new dyno








Again dyno figures mean nothing, real world on road performance is all about midrange overtaking quality, most 4.25's we test do 100-200 kmh in 6.7/8 seconds, this and most others are 6 flat or high 5's, my stage 4.5 was 5.1 bigger turbo cars are low 3 seconds.


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## Skint (Oct 11, 2014)

Is that dynojet dyno?


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## dudersvr (May 7, 2003)

Skint said:


> Is that dynojet dyno?


That is what it says on the printout:squintdan


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## Skint (Oct 11, 2014)

It***8217;s not a very clear pic that***8217;s all.


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## Skint (Oct 11, 2014)

Would have been nice to see before and after pulls to get a ball park on the gains.


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## dudersvr (May 7, 2003)

Skint said:


> Would have been nice to see before and after pulls to get a ball park on the gains.


Ive messaged dimitri to see if we still have them but hes on the dyno in Greece.
The graph is a bit misleading because the 711 figure is right at the end, realistically that a 690 something pull.
This is why I hate dyno figures, would much rather quote performance figures like 100-200kmh or 60-130mph does not matter what the dyno says its what it does on the road or track. A 5.9 100-200 car is much faster than 6.9.


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## kindai (Feb 8, 2016)

dudersvr said:


> Now the proof of the pudding is in a time ticket, pulls on road are fine but down to driver etc, dynos are fine but all read different and can be fudged. The one irrefutable thing to prove power is the terminal speed in a 1/4 mile, it matters not how the car leaves the line it will always be pretty accurate and a very good indication of power. The fastest 4.25 ive seen is Ray McNallys teal blue car that run the pod all the time, his terminals are always 126/7 and may have hit 128. This car ran 4 times, I have a pic of 2 runs and he is adamant the car did 130 on one of the other runs but only can find this ticket


This is mine:

Stage 4, intakes, injectors, STOCK DOWNPIPES, 102 stainless system. 










Ive actually gone better than this since but cant find the timeslip, so you know, drag rules, no slip so it didnt happen


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## kindai (Feb 8, 2016)

kindai said:


> Ive actually gone better than this since but cant find the timeslip, so you know, drag rules, no slip so it didnt happen



Oh actually, it did happen, someone videoed it 

This was a shit start as well.


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## dudersvr (May 7, 2003)

kindai said:


> This is mine:
> 
> Stage 4, intakes, injectors, STOCK DOWNPIPES, 102 stainless system.
> 
> ...


Do you still have the cats in?
Says stage 4.5 in the title


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## kindai (Feb 8, 2016)

dudersvr said:


> Do you still have the cats in?
> Says stage 4.5 in the title



Yes, cats still in.

And not my videos, he assumed I was 4.5, but im a lowly stage 4.


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## Skint (Oct 11, 2014)

I was***8217;nt questioning the out right dyno numbers,just before and after results for my own curiosity. I***8217;ve always thought std airboxes were***8217;nt too bad, so this is a little bit more to supporting my own theories.

As you state there***8217;s only one place to show your gains and it***8217;s out there on the road or track.

My own personal theory or preference in a road car is a well delivered 700 bhp conversion on std turbo***8217;s, or a little more if available.


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## dudersvr (May 7, 2003)

kindai said:


> Yes, cats still in.
> 
> And not my videos, he assumed I was 4.5, but im a lowly stage 4.


Then hats off sir I have never seen a car with the cats in make enough power to run that speed, normal hp for a catted car is 630 which will not run that fast, quite what consequences are running that power with cats in terms of EGT etc I wouldnt know but just shows maybe the 4.25 outlay is not needed.
Just a thought, have you physically checked to make sure the cats are there? we had one car where the cat was gone in one downpipe !!!!


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## Skint (Oct 11, 2014)

What size injectors did you use?


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## barry P. (May 9, 2010)

John, might be worthwhile to state how much it would cost to repeat this exercise in case some others might want to go down this route.


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## kindai (Feb 8, 2016)

dudersvr said:


> Then hats off sir I have never seen a car with the cats in make enough power to run that speed, normal hp for a catted car is 630 which will not run that fast, quite what consequences are running that power with cats in terms of EGT etc I wouldnt know but just shows maybe the 4.25 outlay is not needed.
> Just a thought, have you physically checked to make sure the cats are there? we had one car where the cat was gone in one downpipe !!!!



Its a straight through system from the downpipes back, if the cats were gone it would blow your head off with the noise :chuckle: Thats why I still have them for now, keeps the exhaust in moderation.


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## dudersvr (May 7, 2003)

Skint said:


> What size injectors did you use?


1050 ASNU, plenty left in reserve and not much difference in price for smaller ones.
Plus most tuner base maps for this are done on using a 1050 injector


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## dudersvr (May 7, 2003)

barry P. said:


> John, might be worthwhile to state how much it would cost to repeat this exercise in case some others might want to go down this route.


You would be looking at cost of injectors plus 2.5/3 hours labour plus a remap
so £225/50 plus £450 road map and £650 on dyno (on cars with ecutek licence).
Caveat being this car had Y pipe fitted
He got injectors for £400 and only paid extra for fitting them as we had dp's off for housing change, cheapest performance ive seen LOL :squintdan:squintdan


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## dudersvr (May 7, 2003)

kindai said:


> Its a straight through system from the downpipes back, if the cats were gone it would blow your head off with the noise :chuckle: Thats why I still have them for now, keeps the exhaust in moderation.


Gotcha, that adds up. Cheaper option is definitely a Y pipe and stock exhaust.


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## Skint (Oct 11, 2014)

Does £450 get you ecutek file to a std ecu including map?version 6?


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## dudersvr (May 7, 2003)

Skint said:


> Does £450 get you ecutek file to a std ecu including map?version 6?


Sorry, no should have made that clear, thats a remap on a car with ecutek licence but also SD conversion.
I would highly reccomend its done on the dyno to 1) optimise power 2) 100% check torque is where we want it.


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## herman (Apr 1, 2007)

dudersvr said:


> You would be looking at cost of injectors plus 2.5/3 hours labour plus a remap
> so £225/50 plus £450 road map and £650 on dyno.
> Caveat being this car had Y pipe fitted
> He got injectors for £400 and only paid extra for fitting them as we had dp's off for housing change, cheapest performance ive seen LOL :squintdan:squintdan


Well I know where I"ll be going when I finally get my 35 that's for sure.
Good info john :bowdown1:


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## dudersvr (May 7, 2003)

herman said:


> Well I know where I"ll be going when I finally get my 35 that's for sure.
> Good info john :bowdown1:


Its a slippery slope from there though !!!!
If I had the money I paid for mine and spent on it now I think Id go for a MY17/18 stage 4.25.


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## herman (Apr 1, 2007)

dudersvr said:


> Its a slippery slope from there though !!!!
> If I had the money I paid for mine and spent on it now I think Id go for a MY17/18 stage 4.25.


Well my budgets gone up now so looking to get a 17 plate.And then I"ll be giving you a bell mate:thumbsup:


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## dudersvr (May 7, 2003)

Nice


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## simGTR (Aug 5, 2017)

Seeing as I have previous data, thought I'd make the Dyno comparison. This being a different Dyno is a liable to the usual limitations we expect.


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## Imran (May 6, 2017)

I have an akrapovic full system with standard downpipes. I assume you are referring to removing the cats by the downpipes? If they are removed will that increase the exhaust note and drone? I assume it will fail mot too?


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## dudersvr (May 7, 2003)

Imran said:


> I have an akrapovic full system with standard downpipes. I assume you are referring to removing the cats by the downpipes? If they are removed will that increase the exhaust note and drone? I assume it will fail mot too?


Yes, Yes and Yes im afraid, most tuners have an MOT guy they use and 'fit a stock Y pipe for the test' which is removed afterwards.


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## Big Stewy (May 1, 2008)

Has anybody got and idea what bop/torque would be achieved by going to stage 4.25 on MY17/18?


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## dudersvr (May 7, 2003)

Big Stewy said:


> Has anybody got and idea what bop/torque would be achieved by going to stage 4.25 on MY17/18?


Should be plenty of cars with dyno sheets but I believe its the same power as its almost always ltd to save the motor and box.


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## simGTR (Aug 5, 2017)

Big Stewy said:


> Has anybody got and idea what bop/torque would be achieved by going to stage 4.25 on MY17/18?


New dash is worth 5bhp


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## Big Stewy (May 1, 2008)

Is that still the same power and torque as the CBA & DBA which had less straight from the factory? Anybody got a MY17 car that is at 4.25 and has a Dino that they can share?


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## dudersvr (May 7, 2003)

Big Stewy said:


> Is that still the same power and torque as the CBA & DBA which had less straight from the factory? Anybody got a MY17 car that is at 4.25 and has a Dino that they can share?


The problem is not getting power it is managing it. The jump from CBA to DBA was mostly the suction pipe increase, the crank and rods are still the same as are the gears.


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## gtr mart (Mar 29, 2004)

I ran 10.99 / 130mph with a 1.8 60ft at stage 4.25. Mine is only around 600lbft and 650bhp. It's mostly in the way the car gets off the line. In the real world (on the road) there is little performance difference between a stage 1 car and stage 4. You could also argue that my best time is less than 0.01 seconds faster but it means I get to use these two great movie lines:

1) if you're not first your last

2) I live my life 10 seconds at a time


IN all seriousness I think a lot of the drag racing comes to how well the track is prepped, the mechanical grip the car has (alignment, tyres, suspension), track prep and traction control (my 10.99 was with cobb V2 which has no decent traction strategies and just relies on modulating throttle and how you rev it and get through the gears).

No doubting that's good performance and times for little outlay. Nice to see.


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## dudersvr (May 7, 2003)

gtr mart said:


> I ran 10.99 / 130mph with a 1.8 60ft at stage 4.25. Mine is only around 600lbft and 650bhp. It's mostly in the way the car gets off the line. In the real world (on the road) there is little performance difference between a stage 1 car and stage 4. You could also argue that my best time is less than 0.01 seconds faster but it means I get to use these two great movie lines:
> 
> 1) if you're not first your last
> 
> ...


Terminal speed is nothing to do with how you bet off the line it will always be there or there abouts as long as you are in the throttle.


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## aki (May 1, 2003)

what do you think was a bigger factor in the performance this car produced; 
Decatted downpipes 
or
Speed Density tune

I am in interested in doing similar mods; intakes, injectors, mid-pipe but wanted to keep catted downpipes and MAF. Obviously my car wont make as much power as the car in this thread but I wonder how much I would make?




dudersvr said:


> Well guys thanks for chipping in. Heres what we found when we were asked to cut corners due to finances and incorrect parts.
> Customer brought car in with a nasty vibration (with car stationary), we isolated to the engine and I made the decision it was the transfer plate/ bell housing (bell housing had a decent amount of play). He was on a strict budget having spent out on other parts of the car but after calling and saying 'Hey as downpipes have to come off to swap housings can we put downpipes back on? Yes we say but may need remap (he had a stage 1 so had ecutek licence) so he sources some very cheap downpipes from Ebay (needs must etc) then a while later another call how much to fit injectors and do we have any used ones? So he is told price and as luck would have it we had an almost new set from a customers car and it was someone he knew, he strikes a deal where he can pay for them later in the month, then he does the same with air intakes.
> 
> So we change plate and housing and fit downpipes, they done fit his custom y pipe as it has no flexi section and the are 10mm out either side, likewise the air intakes are too big and have the wrong reducers as they came off a bigger power car with big stock location turbos. So we call him and he is slightly deflated as he is looking forward to a quicker car with a very bargain 4.25 conversion. What can we do he asks, the only thing I can do is knock the cats out of his stock pipes, what about the stock air boxes? They will have to stay he is told, you can add intake kit later and if the map needs a tweak then we can do that.
> ...


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## Stealth69 (Jan 6, 2005)

you can't have a decat without the retune so it would be hard to say...... well I guess you could but you never would.

You can do the SD Tune and not tough the DP's but not vice versa in all reality.

Any reason you want to keep the Catted Downpipes? you could have decatted downpipes, catted Y-Pipe which is less restrictive and will allow you to pass an MOT, you'll get more gains than changing the Y-Pipe and keeping the std cats in the DP, quick retune and Boom..... quick responding car.


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## aki (May 1, 2003)

Regardless to which route I go down, I would definitely get the car re-mapped. I am just weighing up the Pros Vs Cons of doing the down pipes.

The reason for leaving the cats in the down pipes was because I didn't think removing them free'd up a great deal of power? I read a thread on here a while ago where Ryan.G did before and after comparison with catted and decatted down pipes (see link below). Also read about so many people breaking stud(s) when trying to remove the down pipes. Seems too much hassle for not much gain? 

https://www.gtr.co.uk/forum/159486-downpipes.html

As for the Speed Density, I would consider getting that as I like the idea of fitting BOV's to my car. Again read a few things on the net about MAP cars not being as smooth at low RPM/Load compared to MAF cars?


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## aki (May 1, 2003)

*Standard or uprated fuel pump*

Was this car running standard or uprated fuel pumps?

Don't seem to read much on this forum about people upgrading the fuel pumps when chasing stage 4.25.
Over on the GTR life forum most people either change or recommend changing to a higher flowing fuel pump when going for FBO (equivalent to 4.25).


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## simGTR (Aug 5, 2017)

aki said:


> Was this car running standard or uprated fuel pumps?
> 
> Don't seem to read much on this forum about people upgrading the fuel pumps when chasing stage 4.25.
> Over on the GTR life forum most people either change or recommend changing to a higher flowing fuel pump when going for FBO (equivalent to 4.25).


You are incorrect, the equivalent FBO stages are:

stage 1 : Bolt

stage 2 : Bolt-On

stage 3 : Semi Bolt On

stage 4 : Full Bolt-On

stage 4.25 : Full Hard-On

stage 4.5 : Boner


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## terry lloyd (Feb 12, 2014)

aki said:


> Was this car running standard or uprated fuel pumps?
> 
> Don't seem to read much on this forum about people upgrading the fuel pumps when chasing stage 4.25.
> Over on the GTR life forum most people either change or recommend changing to a higher flowing fuel pump when going for FBO (equivalent to 4.25).


They have e85 in the US when using this you need the fuel pumps - not really needed on pump fuel - a data log will tell you if its going lean on the AFR


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## dudersvr (May 7, 2003)

aki said:


> Was this car running standard or uprated fuel pumps?
> 
> Don't seem to read much on this forum about people upgrading the fuel pumps when chasing stage 4.25.
> Over on the GTR life forum most people either change or recommend changing to a higher flowing fuel pump when going for FBO (equivalent to 4.25).


Stock pumps


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## dudersvr (May 7, 2003)

aki said:


> what do you think was a bigger factor in the performance this car produced;
> Decatted downpipes
> or
> Speed Density tune
> ...


What exhaust are you running? There is an option to use 200CEL catted downpipes but that would not be a budget build.
The SD I much prefer and it does seem to result in more power and a bonus that if a boost pipe blows off or splits you can still drive home


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## Stealth69 (Jan 6, 2005)

aki said:


> Regardless to which route I go down, I would definitely get the car re-mapped. I am just weighing up the Pros Vs Cons of doing the down pipes.
> 
> The reason for leaving the cats in the down pipes was because I didn't think removing them free'd up a great deal of power? I read a thread on here a while ago where Ryan.G did before and after comparison with catted and decatted down pipes (see link below). Also read about so many people breaking stud(s) when trying to remove the down pipes. Seems too much hassle for not much gain?
> 
> ...


It's not just the top BHP figure you are interested in, it's the characteristics of the car and removing the cats = less restrictions= faster spoiling turbo= more BHP quicker and lower down in the rev range = quicker car and as the car will be tuned you benefit from less heat. 

Win win


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## aki (May 1, 2003)

Haha, that was actually quiet funny



simGTR said:


> aki said:
> 
> 
> > Was this car running standard or uprated fuel pumps?
> ...


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## aki (May 1, 2003)

No uprated pump required because we don't run E85 here in the UK. 
Ok, that makes sense. 



terry lloyd said:


> They have e85 in the US when using this you need the fuel pumps - not really needed on pump fuel - a data log will tell you if its going lean on the AFR


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## aki (May 1, 2003)

At the moment I'm still undecided if I'll go downpipes or not?

I'm still contemplating whether I just go;

Stage 2: intakes + mid pipe only
Or
Stage 4: intake, downpipe, mid pipe and injectors?




Stealth69 said:


> It's not just the top BHP figure you are interested in, it's the characteristics of the car and removing the cats = less restrictions= faster spoiling turbo= more BHP quicker and lower down in the rev range = quicker car and as the car will be tuned you benefit from less heat.
> 
> Win win


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## aki (May 1, 2003)

I wasn't planning on getting an exhaust, just changing the midpipe.

Is the factory exhaust that restrictive? I always thought the main restrictions were from the cats in down + mid pipes?



dudersvr said:


> What exhaust are you running? There is an option to use 200CEL catted downpipes but that would not be a budget build.
> The SD I much prefer and it does seem to result in more power and a bonus that if a boost pipe blows off or splits you can still drive home


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## Stealth69 (Jan 6, 2005)

No the standard back section isn't overly restrictive, you may lose a touch top end but you'll never notice that


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## Lee-GTR35 (Feb 9, 2018)

I recently had a few runs up the santa pod strip, *NO LAUNCH, STOCK DOWNPIPES*, 3 runs i decided to complete, all around 128/129 mph over the 1/4

Unfortunatley due to not having enough posts, i can send links but i can after this message LOL


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## Lee-GTR35 (Feb 9, 2018)

The links now i have 3 posts LOL

https://www.youtube.com/watch?v=-n6HZUDkeQU


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## aki (May 1, 2003)

129 terminal speed is pretty impressive.
What mod's does your car have?



Lee-GTR35 said:


> I recently had a few runs up the santa pod strip, *NO LAUNCH, STOCK DOWNPIPES*, 3 runs i decided to complete, all around 128/129 mph over the 1/4
> 
> Unfortunatley due to not having enough posts, i can send links but i can after this message LOL


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## dudersvr (May 7, 2003)

Lee-GTR35 said:


> I recently had a few runs up the santa pod strip, *NO LAUNCH, STOCK DOWNPIPES*, 3 runs i decided to complete, all around 128/129 mph over the 1/4
> 
> Unfortunatley due to not having enough posts, i can send links but i can after this message LOL


Nice runs, whats becoming clear is that maybe new versions of tune, prob Ecutek are making the cars faster.

The whole point of the post was to inform people that the same power is available a lot cheaper, most cars I see have a y pipe as a minimum so just a set of injectors and tune is enough to see the same gains as laying between 3.5-4.5K. I think it was Lee at SRD ran a very good time with next to no mods.
Would be interesting to see how people feel about the following question
Stage 4.25 .................................... lets say 680hp £4000
same performance with half the mods £1500

who would go genuine 4.25 knowing the facts?


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## vxrcymru (Sep 29, 2009)

Simple, the ones who can't afford to pay 4k


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## Lee-GTR35 (Feb 9, 2018)

aki said:


> 129 terminal speed is pretty impressive.
> What mod's does your car have?


Its a Litchfield stage 4 

ECUTEK ECU
1050cc injectors.
Cone airfilters.
Titan 102 titanium exhaust ( i had to get it when it was on a black friday deal )
275/305 MP4S

I believe i could get a very low 11 or a high 10 if i launched it, but tbh i enjoy the car how it is currently set up


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## gtr mart (Mar 29, 2004)

looking at your 60ft times you definatly have a high ten there. With launch you should be able to hit 1.8 60ft which will bring your terminal down by 0.2 / 0.4 secs.


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## herman (Apr 1, 2007)

I personaly think people who have the money to go to 4.25 stage would still consider why am I throwing away a couple of grand when I don't need to and spend it on something else on the car like the handling/brakes/cosmetic?? Just because you"ve got it doesn't mean you need to waste it. :smokin:


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## gtr mart (Mar 29, 2004)

It would depend on how the car sounds with the gutted DP's. Anything after stage 1 only really adds 'drama' on the road. Also, if you added the rest of the stage 4.25 bits to the OP car and returned, would it go even faster?


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## simGTR (Aug 5, 2017)

My other car is getting a rebuild, my conversation with the engine builder:

"Matt, i'm thinking of leaving the cats in, do you think it will make much difference"

"When people are chasing power, I've never known anyone to add them"


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## terry lloyd (Feb 12, 2014)

simGTR said:


> My other car is getting a rebuild, my conversation with the engine builder:
> 
> "Matt, i'm thinking of leaving the cats in, do you think it will make much difference"
> 
> "When people are chasing power, I've never known anyone to add them"


if they are not going to effect your power goal would you still change them ?


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## simGTR (Aug 5, 2017)

terry lloyd said:


> if they are not going to effect your power goal would you still change them ?


I'm actually leaving them in because it will be fast enough at it is. That and it's a road car.

If my 4.25 was bought as a stage 4, I would have left that too, but alas, I bought it already done.


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## aki (May 1, 2003)

I would be aiming for similar spec but without the full exhaust system.

I think with more tracked focused tyres (R888R or Cup 2) and using launch control you could get into the 10's? 



Lee-GTR35 said:


> Its a Litchfield stage 4
> 
> ECUTEK ECU
> 1050cc injectors.
> ...


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## Stealth69 (Jan 6, 2005)

I think with more track focused tyres and launch control you're looking to a broken gearbox not low 10's at stage 4.25


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## terry lloyd (Feb 12, 2014)

I am not sure you can heat track tyres enough at a drag strip - John and Mart are the drag guru`s but i suspect a dedicated drag map will be a good idea if chasing times - boost by gear etc


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## aki (May 1, 2003)

in that case just stick with current set up LOL.


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## TAZZMAXX (Mar 9, 2010)

Does this mean that tuners have been charging gullible R35 owners more than they needed to over the past 10 years? I’m shocked:chuckle:


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## dudersvr (May 7, 2003)

Stealth69 said:


> I think with more track focused tyres and launch control you're looking to a broken gearbox not low 10's at stage 4.25


What breaks the trans is wheel hop, hooking up is your friend.


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## gtr mart (Mar 29, 2004)

terry lloyd said:


> I am not sure you can heat track tyres enough at a drag strip - John and Mart are the drag guru`s but i suspect a dedicated drag map will be a good idea if chasing times - boost by gear etc



I agree Terry. I ran cup2s which are supposedly R compound track tyres and struggled to get enough warmth into them. Mind you, I swapped to MPSS 335 on the rear noting the lack of warmth and didn't manage to improve my 60ft or ET. Go figure! 

I think a stock car, with appropriate alignment, suspension, tyres and perhaps a DSC suspension controller (unless on drag suspension) would run a faster 1/4 than a 4.25 that just rocked upto the track. Plus of course appropriate launch control settings and knowing what you're doing.



Also agree with John. It's wheel hop that destroys your drivetrain, starting with your clutch baskets. A good pair of slicks are infact easier on the tranny than drag radials or worse still road tyres.


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## Stealth69 (Jan 6, 2005)

dudersvr said:


> What breaks the trans is wheel hop, hooking up is your friend.


Is hooking up not harsher on the clutches and more prone to stripping gears?


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## DeeboSTI (Dec 1, 2016)

TAZZMAXX said:


> Does this mean that tuners have been charging gullible R35 owners more than they needed to over the past 10 years? I’m shocked:chuckle:


:chuckle:


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## dudersvr (May 7, 2003)

Stealth69 said:


> Is hooking up not harsher on the clutches and more prone to stripping gears?


Obviously more strain than a road tyre on the road but its shock loading that breaks gears, a drag radial will put more strain than a slick as the slick takes some of the hit out of it, same way our modded prop saves the front diff, it takes the hit and vibration out of the drivetrain to the front diff.
See pic of a stock box thats been launched over 100 times on slicks
I also change the clutch capacities at the strip to like +4 and when it changes its like a sledgehammer hitting the back of the car but there is no slip, if it slips it will overheat stuff and wear out, even on my 20 plate I up the capacities.


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## Stealth69 (Jan 6, 2005)

Cheers makes sense


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## dudersvr (May 7, 2003)

Stealth69 said:


> Is hooking up not harsher on the clutches and more prone to stripping gears?


Best way to get off the line is a tiny amount of wheelspin, no wheelspin is known as deadhooking and in a powerful car not really what you want


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