# Stage 4.25 to 4.5, or, how to discuss something else that may not be connected



## matarmitage88 (Apr 16, 2017)

Hi all
New to this forum. Just after some advise. Currently running stage 4.25 and looking to notch up to 4.5. 
Anyone done this and is it worth the £6k to do so. Car is for road use only and just wanting a little more. 
Any experience or comments greatly appreciated. 
Photo attached too being a newbie 
Thanks
Mat


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## charles charlie (May 3, 2008)

What you are paying for are new turbos, bigger fuel pumps, intercooler, and heavy labour costs as the engine needs dropping to install the turbos.

You'll get around 700 Bhp which is felt at the top of the rpm band where the Oem turbos lose their puff. So your torque band stays up at the tuned limit for a bit longer.

Personally it's a lot of money for an additional 50 horses or so and the torque has to be capped pretty much where it is on your car right now at 600lbsft to protect the rods and gearbox. I'd doubt you'd feel any difference on the road given it's not often you're revving to 7k.

Each to their own of course but for me I'd be saving my pennies for either an engine upgrade to handle more power or handling/interior/AV upgrades instead.


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## Skint (Oct 11, 2014)

I think AC were doing full engine rebuilds (forged) for shy of 7K which would be my choice.

It would allow you to increase torque which would make a better road car and also future proof the engine.

Never been into this hybrid turbo lark, I think there just compromised turbo's as there easy enough for manufacturers to have made but they don't bother.


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## matarmitage88 (Apr 16, 2017)

Thank you

Assume the forged engine option only provides a solid base for further modifications and will see no performance benefit?


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## Stealth69 (Jan 6, 2005)

For that money it would be an AC rebuild all day long, with the new build you'll be able to uncap the turbos you have now giving more available torque etc and you'll feel a much bigger difference than if you went stage 4.5 IMHO. 

The build will also future proof the lump for turbos further on down the line and what not but the gearbox is still a consideration but less of a worry. 

Do a search on here for winter build


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## matarmitage88 (Apr 16, 2017)

Found last years winter build at £5555 just now. Might give Andy a shout on it fit me in when a little less busy. 
For this what increases bhp and torque would you expect from my current situation. ?


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## terry lloyd (Feb 12, 2014)

I would try a better intercooler before anything else - the turbos used in some 4.5 upgrades are a waste of time


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## Skint (Oct 11, 2014)

Forged engine will not directly see any more power on it's own but will allow more ignition timing and boost to be dialed in which will be seen.

Also you have a much newer engine to a degree


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## matarmitage88 (Apr 16, 2017)

Thank you. Sounds like that's the way to go. 
Will make some enquiries with the known guys


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## charles charlie (May 3, 2008)

If you check my build thread I gained around 70hp at the same boost level of 1.2 bar when I went forged.

The more efficient intercooler, larger pipework and ported manifold gave that power increase for the same boost.

A forged engine allows more torque as the safety limit can be increased so an increase in power is inevitable given how power is calculated from rpm and torque.


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## terry lloyd (Feb 12, 2014)

charles charlie said:


> If you check my build thread I gained around 70hp at the same boost level of 1.2 bar when I went forged.
> 
> The more efficient intercooler, larger pipework and ported manifold gave that power increase for the same boost.
> 
> A forged engine allows more torque as the safety limit can be increased so an increase in power is inevitable given how power is calculated from rpm and torque.


I would have thought most of the extra power came from the bigger turbos ? 1.2 bar on the bigger turbos is a lot more air than the oem turbos at 1.2 bar


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## charles charlie (May 3, 2008)

terry lloyd said:


> I would have thought most of the extra power came from the bigger turbos ? 1.2 bar on the bigger turbos is a lot more air than the oem turbos at 1.2 bar


True but we also gained another 40hp at 1.0 bar i.e. No boost.


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## borat52 (Jan 29, 2006)

I've done stage 4 to 4.5 with litchfield's hybrid turbo's.
Car makes 760bhp.

Without wishing to drag the old torque vs power argument up I don't think a forged stage 4.25 would come close to out dragging a stock motor stage 4.5 as you're looking at around an extra peak 100bhp and its power that you need to accelerate mass.

It's noticeably quicker at the top end relative to the stage 4 (600bhp) that I came from but:
1. It does cause me some concern at this state of tune with regards to the longevity of the engine
2. It's probably past the point of making sense in terms of bhp gain/£ spent.

That said the way I see it is that I wouldn't forge the motor unless I was going to add some bigger turbo's and then the gearbox becomes the weak point so I'm sat here now at 620lbft/760bhp for £6k whereas a forged engine and bigger turbos would likely have been around £12-£15k and maybe I'd be something like 700lbft/850bhp and very worried about nuking a gearbox then needing to spend another £10+k to sort that out.

Sweet spot is definitely stage 4/4.25 on these things, anything beyond is either a worry or requires very deep pockets.

Haven't seen him on here recently but mathewk did something like 60 track days at stage 4 without any motor issues.


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## matarmitage88 (Apr 16, 2017)

That's great information. Thank you. 
Lot of money to spend so appreciate everyone's input.


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## Rob S. (Nov 4, 2016)

charles charlie said:


> What you are paying for are new turbos, bigger fuel pumps, intercooler, and heavy labour costs as the engine needs dropping to install the turbos.
> 
> You'll get around 700 Bhp which is felt at the top of the rpm band where the Oem turbos lose their puff. So your torque band stays up at the tuned limit for a bit longer.
> 
> ...


I think you are mistaken here. You can get a lot more then 700bhp on stock block if you have a good tuner. Switzer has a lot of P800 kits (800bhp) on stock block and stock trans and they dont have any issues.

In USA there are a lot of guys that run even more bhp on stock block. 800-850bhp is totally doable if you have a good tuner that can dial in the torque.

That is a 150 or even 200bhp gain over stage 4.25 (650bhp). This will probably drop your 60-130 times from 7-7.5 seconds to around 5.5-6 seconds. 

There are even guys on gtrlife.com than run over 800WHP on stock block for 10.000s miles (Lambo Joe, goonthree etc) and when they decided to built the block all rods were straight as an arrow). Tuning has come a long way and i would not hesitate to run 800-850bhp on stock block with limited torque. This is in fact what i am building right now.


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## dtox (Sep 21, 2009)

borat52 said:


> I've done stage 4 to 4.5 with litchfield's hybrid turbo's.
> Car makes 760bhp.
> 
> Without wishing to drag the old torque vs power argument up I don't think a forged stage 4.25 would come close to out dragging a stock motor stage 4.5 as you're looking at around an extra peak 100bhp and its power that you need to accelerate mass.
> ...


Bit off topic but how are these turbos I've just picked up a set and can't wait to get them installed  I love stage 4.25 but getting bored of it now which is annoying. 

When you run the LM700 turbos I'm buying second hand I saw the dyno run at 786bhp if you forge the internals and box I wonder what the LM700 turbos would run out of puff at when full boost I was hoping to

Run LM700 turbos with 620lbft 
Then forge the engine and box
then run full boost without going silly big turbos with big lag


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## charles charlie (May 3, 2008)

Not sure why you think I'm mistaken Rob.

Power figure I quoted is what Lichfield state is tbeir stage 4.5 upgrade. American horses tend to be bigger than ours so be wary of comparing.

Also my post was intended to outline the fact that torque is still limited to same max level as a stage 4 or 4.25, the only difference is that the torque continues further up the rev band beyond the point where the stock turbos lose puff.

By highlighting this fact I was drawing the OPs attention to the simple fact that the only difference for spending 6k is more usable power at the top of the rev range.

The OP said his car is for road and not track and I questioned how usable that extra top end power and torque will be for him.

He asked whether it was value for money and in my opinion, it isn't.


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## motors (Mar 14, 2013)

dtox said:


> Bit off topic but how are these turbos I've just picked up a set and can't wait to get them installed  I love stage 4.25 but getting bored of it now which is annoying.
> 
> When you run the LM700 turbos I'm buying second hand I saw the dyno run at 786bhp if you forge the internals and box I wonder what the LM700 turbos would run out of puff at when full boost I was hoping to
> 
> ...


These were my turbos you wont be disappointed(if power was 768) you wont be disappointing huge difference over previous stage 4 car especially at top end. I was told by Litchfields there is not much more in the turbos. Big turbos dont always mean big lag EFR turbos spool really well.


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## dtox (Sep 21, 2009)

Maybe ha ha - Did you sell them to Andy R35Audio if yes then deffo your turbos. 
Did you have any issues with the box etc with the turbos on. I'm having issues already at stage 4.25 yet alone with these one. Which I/C did you run and pumps


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## Rob S. (Nov 4, 2016)

charles charlie said:


> Not sure why you think I'm mistaken Rob.
> 
> Power figure I quoted is what Lichfield state is tbeir stage 4.5 upgrade. American horses tend to be bigger than ours so be wary of comparing.
> 
> ...


I understand. But you will certainly also gain torque coming from stage 4.25. 
My car is also only for road use and why would you need more torque in lower rpm? The car has plenty torque down low to move through traffic lol. 

You will for sure feel the 150bhp that you will gain in the higher rpm...and after all....that is the exact RPM range where you will always be when you floor it.

I also dont think that American horses are that much different, they just calculate WHP instead of BHP.


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## motors (Mar 14, 2013)

dtox said:


> Maybe ha ha - Did you sell them to Andy R35Audio if yes then deffo your turbos.
> Did you have any issues with the box etc with the turbos on. I'm having issues already at stage 4.25 yet alone with these one. Which I/C did you run and pumps


That's them  they are in great order. I had Litchfield forge intercooler and LM 340 pumps. No issues with the box. Have fun !


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## matarmitage88 (Apr 16, 2017)

Charles Charlie
Do you have link to your build information so I can have a read please
Thanks
Mat


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## charles charlie (May 3, 2008)

It's in my signature down below


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## charles charlie (May 3, 2008)

Rob S. said:


> I understand. But you will certainly also gain torque coming from stage 4.25.
> My car is also only for road use and why would you need more torque in lower rpm? The car has plenty torque down low to move through traffic lol.
> 
> You will for sure feel the 150bhp that you will gain in the higher rpm...and after all....that is the exact RPM range where you will always be when you floor it.
> ...


If we use your example of the Switzer P800 the best result I can find is 740 bhp.

If we do the maths the only way you can get 800hp is to raise the torque level to around 650 lbsft and have that carrying on to 6500rpm.

Would you want your stock conrods experiencing that?

I'd be unhappy running that even with a car that only sees the road.


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## terry lloyd (Feb 12, 2014)

650ft lbs would probably be ok imo if you dial it in above 5000rpm something you cant do with stock turbos due to the fact they are dying off before then - its the low revs high torque thats the killer


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## Rob S. (Nov 4, 2016)

charles charlie said:


> If we use your example of the Switzer P800 the best result I can find is 740 bhp.
> 
> If we do the maths the only way you can get 800hp is to raise the torque level to around 650 lbsft and have that carrying on to 6500rpm.
> 
> ...


I dont know where you are looking at but i can link you dozens of P800 dyno well over 800 hp (in Germany, Holland etc). 

I would be totally fine with 650 lbft yes. All the FBO E85 cars make this amount torque (around 600-630 WHP and WTQ). A lot of upgraded turbo GTR make a lot more power but less torque to spare the rods from bending. 

I am not good at maths btw


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## charles charlie (May 3, 2008)

Rob S. said:


> A lot of upgraded turbo GTR make a lot more power but less torque to spare the rods from bending.
> 
> I am not good at maths btw


How is that possible Rob?

Power = Torque x RPM / 5252

You cannot drop torque without dropping power they are directly proportional.

Could you post some links for dyno plots for the P800s that are over 800bhp as I can't find any? Cheers


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## Rob S. (Nov 4, 2016)

charles charlie said:


> How is that possible Rob?
> 
> Power = Torque x RPM / 5252
> 
> ...


DYNO GT-R - TCC DEMO - Tuning Stages - Total Car Concept BV

Just one example from the biggest GT-R tuner/shop in Holland. 22psi, 800hp, 900nm. On the road the car makes even more psi which translates to about 840hp and 950nm.


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## charles charlie (May 3, 2008)

Rob S. said:


> DYNO GT-R - TCC DEMO - Tuning Stages - Total Car Concept BV
> 
> Just one example from the biggest GT-R tuner/shop in Holland. 22psi, 800hp, 900nm. On the road the car makes even more psi which translates to about 840hp and 950nm.


I saw that graph and on conversion the peak torque is 660 lbsft at 4500 rpm. 950nm is 700 lbsft on a stock engine? Not on my car I wouldn't!

I don't know many tuners that would be happy with that torque on a stock engine for long and certainly wouldn't want more boost giving even more torque than that. 

It proves my point. The P800 package I've seen quoted as $18,000 fitted and has to have its torque and boost limited because of the stock internals. 

Is that value for money as per the OPs original question?

I'd argue it's an odd way to spend such a large amount of money and have to clip the wings of such a great upgrade because the stock internals are seriously in danger of letting go.

And that was my original answer to the OPs question.

Is 6k a worthwhile spend to go from 4.25 to 4.5?

And I don't see the Switzer package as a stage 4.5 personally.


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## Rob S. (Nov 4, 2016)

charles charlie said:


> I saw that graph and on conversion the peak torque is 660 lbsft at 4500 rpm. 950nm is 700 lbsft on a stock engine? Not on my car I wouldn't!
> 
> I don't know many tuners that would be happy with that torque on a stock engine for long and certainly wouldn't want more boost giving even more torque than that.
> 
> ...


Maybe not on your car but that doesnt mean around 650lbft isnt reliable. That Switzer car has been the shop car for years and years. Never had any problems just like the other P800 cars that run that power. All the Switzer P800 cars deliver this amount of power....in USA they all dyno around 700whp which translates to at least 800bhp.

Like i said almost all of the E85 FBO cars make this kind of torque on stock block. PLUS with E85 FBO the torque hits way harder earlier in the RPM range which is certainly more stressfull on the rods and still all those car run happy when tuned correctly.

I agree that 18k would not be worth it for me. No way. However around 6k for 150+ bhp is really not bad at all. What i am doing right now is Sir USM turbo's, bigger inlets, DW 300 fuel pumps and SD tune on top of my full bolt on setup that i am on right now. This will cost me around 5k ex labour and is totally worth it for me for 150+ bhp extra. Just my 2 cents


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## Chronos (Dec 2, 2013)

charles charlie said:


> I saw that graph and on conversion the peak torque is 660 lbsft at 4500 rpm. 950nm is 700 lbsft on a stock engine? Not on my car I wouldn't!
> I don't know many tuners that would be happy with that torque on a stock engine for long and certainly wouldn't want more boost giving even more torque than that..





Rob S. said:


> Maybe not on your car *but that doesnt mean around 650lbft isnt reliable.* That Switzer car has been the shop car for years and years. Never had any problems just like the other P800 cars that run that power. All the Switzer P800 cars deliver this amount of power....in USA they all dyno around 700whp which translates to at least 800bhp.
> Like i said almost all of the E85 FBO cars make this kind of torque on stock block. PLUS with E85 FBO the torque hits way harder earlier in the RPM range which is certainly more stressfull on the rods and still all those car run happy when tuned correctly.


just to make it a bit more REAL, people throwing numbers around on a forum, saying 650lbft is safe and so on doesnt mean anything, let's get some real life pictures of what DID happen on an R35 GTR, aka my GTR with 650lb/ft and about the same in BHP, may bring it home a bit better! 

So take your chances of you want, and you may be lucky! Hell some are, I wasn't! And if not, expect a 15-20k bill for the repair.

http://www.gtr.co.uk/forum/479825-ouch.html

rod escaped!


















Crank fragged

















[/QUOTE]


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## terry lloyd (Feb 12, 2014)

650FT LBs is not going to be "safe" on a stock block , but with bigger turbos you have more choice of where to bring the torque in also they can run more hp with less boost pressure and a lower charge temp - its a catch 22 why forge without turbos - why turbos without forged engine then you get to the gearbox , really above 4.25 you are going to need to spend 30k + to go get a decent reliable increase


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## Stealth69 (Jan 6, 2005)

The forge vs turbos isn't catch22 if you ask me, with the turbos sure you can run a cooler car etc but you are still limited to 620-640lb/ft if you sit on the safer side of the fence, with the forged engine you can uncap the turbos you have thus getting more torque and bhp out of the existing application making it a quicker can than a 4.5 in all reality. 

Plus with the forge you get peace of mind that the rods aren't going to shat through the side of your block and you can drive the car (rip the arse out of it) without any worry. 
It will be a more useable power as well, instead of making an extra 100bhp up the top you'll have a shit ton more low down grunt

That's my two pence worth


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## dudersvr (May 7, 2003)

Rob S. said:


> I think you are mistaken here. You can get a lot more then 700bhp on stock block if you have a good tuner. Switzer has a lot of P800 kits (800bhp) on stock block and stock trans and they dont have any issues.
> 
> In USA there are a lot of guys that run even more bhp on stock block. 800-850bhp is totally doable if you have a good tuner that can dial in the torque.
> 
> ...


Buying turbos that can run 850hp and limiting the torque to stock is like dating a super model with the clap, looks great and bragging rights down the pub but cant really enjoy it to its full potential!!! Bit of a tease really:chuckle:


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## Rob S. (Nov 4, 2016)

dudersvr said:


> Buying turbos that can run 850hp and limiting the torque to stock is like dating a super model with the clap, looks great and bragging rights down the pub but cant really enjoy it to its full potential!!! Bit of a tease really:chuckle:


I dont agree with this at all. For me the car has plenty power down low, really dont need any more. I only need more HP in the upper RPM range where the stock turbo's fall flat on their face. This is where the upgraded turbo's shine and this is the RPM range where you will always be when you floor it.


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## Rob S. (Nov 4, 2016)

Chronos said:


> just to make it a bit more REAL, people throwing numbers around on a forum, saying 650lbft is safe and so on doesnt mean anything, let's get some real life pictures of what DID happen on an R35 GTR, aka my GTR with 650lb/ft and about the same in BHP, may bring it home a bit better!
> 
> So take your chances of you want, and you may be lucky! Hell some are, I wasn't! And if not, expect a 15-20k bill for the repair.
> 
> ...


[/QUOTE]

I am sorry too see that!

However this is just a case of bad luck OR bad tuning. There are literally thousands of GT-R's running +650bhp for 10.000's miles without any problem.

There are even some cases of 100% stock GT-R's that had this problem. Like i already said probably just bad luck or bad tuning.


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## dudersvr (May 7, 2003)

Rob S. said:


> I dont agree with this at all. For me the car has plenty power down low, really dont need any more. I only need more HP in the upper RPM range where the stock turbo's fall flat on their face. This is where the upgraded turbo's shine and this is the RPM range where you will always be when you floor it.


Theres an old saying a bit like the golf one

'Drivings for show Puttings for dough'

'HP is for bragging, Torque wins races'

If you increase the HP the car will accelerate the same but have a higher speed at a given point ie 1/4 mile, so your ET will remain the same but terminal quicker! Not much good on the road!

BUT if you increase torque the car will accelerate quicker (ideal for road) and is far easier to drive fast.

When I fitted my BB turbos I gained 10-12 mph in 1/4 mile but only about 0.2 secs ET, only by fitting slicks did I cut my ET so its not a lot faster in acceleration stakes, now as a trackday car you might get some value for money but the OP stated not a track car:smokin:


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## dudersvr (May 7, 2003)

I am sorry too see that!

However this is just a case of bad luck OR bad tuning. There are literally thousands of GT-R's running +650bhp for 10.000's miles without any problem.

There are even some cases of 100% stock GT-R's that had this problem. Like i already said probably just bad luck or bad tuning.[/QUOTE]

Yeah not a sight we want to see !!!! Yes there are 1000's of GTR's running that torque (me included) but its not a case of if its a case of when, hence mine is being forged right now as I dont like the feeling of driving with a grenade under the bonnet with the pin pulled but wrapped in plastic slowly melting that merely delays the big bang. Theres also many GTR's have lost motors at a lower torque, this shows that the motor is not as strong as some guys like to think and the potential will never be unlocked until a forged bottom end is used as tuners never want to have their name attached to blown motors, in fact many will stipulate that if the fix or contribute to a blown motor there is never anything published, so you dont even know how many failures there really are.


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## borat52 (Jan 29, 2006)

dudersvr said:


> Theres an old saying a bit like the golf one
> 
> 'Drivings for show Puttings for dough'
> 
> ...


What you're saying is incorrect in general. It might be correct in a very specific situation but not true across the board.

Increasing BHP at every point on the graph (all other things equal) will result in faster ET AND faster terminal.

If you increase peak bhp at the expense of bhp lower down the rev range (ie perhaps lower peak torque) then you might experience what you are describing depending on the gearing but this becomes far less relevent with decent close(ish) ratio DCT boxes.

Without going down the rabbit hole again power across the rev range that your doing the work is what accelerates a car.

Formula one cars have relatively low torque in their power band (300-400lbft at most), yet they'll out accelerate almost anything once they are rolling.


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## borat52 (Jan 29, 2006)

This was my original tune dyno at stage 4.5 with intercooler, pretty conclusive that stage 4.5 makes very good numbers imho.


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## dudersvr (May 7, 2003)

borat52 said:


> What you're saying is incorrect in general. It might be correct in a very specific situation but not true across the board.
> 
> Increasing BHP at every point on the graph (all other things equal) will result in faster ET AND faster terminal.
> 
> ...


Well my car proves it, if you read the comment, I was already running as much torque as we dared but changed to BB turbos that produced a lot more up top yet the car only gained 0.2 secs on the 1/4 mile

A formula ! car weighs naff all thats why it accelerates so fast, heavier the car the more it benefits from high torque and as low down as possible.


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## dudersvr (May 7, 2003)

borat52 said:


> This was my original tune dyno at stage 4.5 with intercooler, pretty conclusive that stage 4.5 makes very good numbers imho.


Good numbers, prob the same as mine before engine build, will be interesting to see how much difference on a drag strip the new higher torque will make as turbos are staying the same for the time being.


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## Rob S. (Nov 4, 2016)

dudersvr said:


> Theres an old saying a bit like the golf one
> 
> 'Drivings for show Puttings for dough'
> 
> ...


No offence but i think you need to read more on gtrlife.com. There are A LOT of stock block cars with upgraded turbos running high 9's all day. No way this is possible on stock turbo (yes maybe a hand full in the whole world that run 9's on stock turbos). 

You also need to take a look at the 60-130 times of upgraded turbo cars. They gain at least (!) 1-1.5 secs coming from FBO E85. Maybe 1-1.5 secs doenst seem like a lot but we are talking multiple bus lenghts from 60-130. And the FBO E85 cars already make quite a bit more bhp and torque then the normal stage 4.25 cars on regular gasoline (98 RON).

Obviously you have to be in the right power band to feel the real difference, but like i already said multiple times that is were we all are when racing on the road. Nobody is starting a roll race from 2-3k RPM. We are all above 4.5-5k RPM and this is were you will have around 150bhp extra.


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## dudersvr (May 7, 2003)

Rob S. said:


> No offence but i think you need to read more on gtrlife.com. There are A LOT of stock block cars with upgraded turbos running high 9's all day. No way this is possible on stock turbo (yes maybe a hand full in the whole world that run 9's on stock turbos).
> 
> You also need to take a look at the 60-130 times of upgraded turbo cars. They gain at least (!) 1-1.5 secs coming from FBO E85. Maybe 1-1.5 secs doenst seem like a lot but we are talking multiple bus lenghts from 60-130. And the FBO E85 cars already make quite a bit more bhp and torque then the normal stage 4.25 cars on regular gasoline (98 RON).
> 
> Obviously you have to be in the right power band to feel the real difference, but like i already said multiple times that i were we all are when racing on the road. Nobody is starting a roll race from 2-3k RPM. We are all above 4.5-5k RPM and this is were you will have at least 150bhp extra.


I dont need to read anything on GTR life my best time was 10.3 letting off at 1000ft and losing 10mph off my normal terminal thats stock block, box and clutch, like I said im same spec as you and the cars only noticeably differnt in the last 1500rpm, is it worth 6K? No will it be with a built motor and over 700 ft lbs? Hell yeah.


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## borat52 (Jan 29, 2006)

dudersvr said:


> Well my car proves it, if you read the comment, I was already running as much torque as we dared but changed to BB turbos that produced a lot more up top yet the car only gained 0.2 secs on the 1/4 mile
> 
> A formula ! car weighs naff all thats why it accelerates so fast, *heavier the car the more it benefits from high torque and as low down as possible*.


That's not correct. Power accelerates mass not torque.
Put it this way, if you make peak torque at 3k rpm but do all your work from 5-7k rpm how is the peak torque number relevant in any way to acceleration?


It will be true that bigger turbo's make more torque, and hence power, higher up the rev range which is why you will see improved acceleration, all other things equal.


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## e8_pack (Sep 22, 2013)

Rods for me i think, i just want stock turbos running at max boost, but with no danger of grenading the engine. Already had it happen on a previous car, don't want it to happen again!


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## borat52 (Jan 29, 2006)

dtox said:


> Bit off topic but how are these turbos I've just picked up a set and can't wait to get them installed  I love stage 4.25 but getting bored of it now which is annoying.
> 
> When you run the LM700 turbos I'm buying second hand I saw the dyno run at 786bhp if you forge the internals and box I wonder what the LM700 turbos would run out of puff at when full boost I was hoping to
> 
> ...


You won't make any more power than 750-780bhp out of these, they are absolutely maxed even on stock internals as they can't flow enough air to maintain boost at high RPM's.

If you forge with them you'll see some extra torque low down, I can't speak from experience but at a guess you've got a chance of somewhere close to 700lbft from 4-5k rpm but after that they'll very quickly fall off, they'll look exactly like my plot from 5k rpm onwards as it's not torque limited from there but turbo limited.

If your forging your engine, don't bother with these turbo's - go with the EFR's.

These are the most cost effective way of getting to 750bhp and retaining stock like spool which you could argue is a sensible place to stop unless you want to throw huge money at the car.

I think Litchfield will offer their warranty on these at 600lbft/750bhp as long as you tick all their other boxes whereas Iain is on here as saying he wouldn't offer a warranty at 800bhp on a stock block which tells something of a story with regards to where the limits of the stock block are.

I personally think 600lbft/650bhp is a nice conservative level at which I wouldn't have any worries (you can always be unlucky). 650lbft/800bhp for me is a worry.

Don't have my latest dyno to hand but I think I'm currently at 620/760 which makes me slightly uncomfortable.


----------



## dudersvr (May 7, 2003)

borat52 said:


> That's not correct. Power accelerates mass not torque.
> Put it this way, if you make peak torque at 3k rpm but do all your work from 5-7k rpm how is the peak torque number relevant in any way to acceleration?
> 
> 
> It will be true that bigger turbo's make more torque, and hence power, higher up the rev range which is why you will see improved acceleration, all other things equal.


Torque is acceleration power is top speed, you can argue all you like my car was no faster other than 0.2 secs over 1/4 mile with more power and approx same torque.
Have you got actual comparison figures to show different? Plus my best times on stock turbos is short shifting. With the BB turbos I can rev it more but the timeslips dont lie and Terminal shows the extra power.
How do you explain diesel cars that run fast and make more torque than HP?


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> I dont need to read anything on GTR life my best time was 10.3 letting off at 1000ft and losing 10mph off my normal terminal thats stock block, box and clutch, like I said im same spec as you and the cars only noticeably differnt in the last 1500rpm, is it worth 6K? No will it be with a built motor and over 700 ft lbs? Hell yeah.


Well maybe we just have a different opinion OR your car just did not run a ''agressive'' tune and made a lot less then 800bhp. I can show you multiple 1/4th slips with upgraded turbos that do 9's all day. Can also show you multiple vbox logs that they shaved 1.5 seconds from their 60-130 which will be a HUGE gap. This is from just upgrading the turbos and tune, everything else remains the same. 

I dont know but going from a 130mph trap speed to a 140mph trap speed is a very, very large difference. Will make a insane difference when doing roll racing on the street.


----------



## dudersvr (May 7, 2003)

Rob S. said:


> Well maybe we just have a different opinion OR your car just did not run a ''agressive'' tune and made a lot less then 800bhp. I can show you multiple 1/4th slips with upgraded turbos that do 9's all day. Can also show you multiple vbox logs that they shaved 1.5 seconds from their 60-130 which will be a HUGE gap. This is from just upgrading the turbos and tune, everything else remains the same.
> 
> I dont know but going from a 130mph trap speed to a 140mph trap speed is a very, very large difference. Will make a insane difference when doing roll racing on the street.


The tune will be a lot more aggressive when it comes back for sure but I did say I had to peddle from 1000ft.


----------



## borat52 (Jan 29, 2006)

dudersvr said:


> *Torque is acceleration power is top speed*, you can argue all you like my car was no faster other than 0.2 secs over 1/4 mile with more power and approx same torque.
> Have you got actual comparison figures to show different? Plus my best times on stock turbos is short shifting. With the BB turbos I can rev it more but the timeslips dont lie and Terminal shows the extra power.
> How do you explain diesel cars that run fast and make more torque than HP?


Just re-read what you've written there, you appear to be under the impression that you can attain a higher top speed over a given distance with a lesser acceleration which is impossible.

At a stab your figures are not what one would expect due to the higher power causing traction issues, which effectively means you reach 30/60ft slower so you have to then make up the time over the rest of the run.

Regardless of the ins and outs of your run, I can explain my methodology with established physics equations, which if you can disprove will get you a nobel prize and an a lot of money.

A MUCH better measurement would be a rolling start of say 30-100mph as you negate the traction issues which are very hard to model and repeat consistently back to back.

Give me an example of a diesel car which runs fast with a dyno plot and the change points and I'll exactly demonstrate how it's doing it.

Power accelerates mass, not torque.


----------



## e8_pack (Sep 22, 2013)

Subbed for internet nerd off.


----------



## TAZZMAXX (Mar 9, 2010)

e8_pack said:


> Subbed for internet nerd off.


There's plenty of that to see on this forum:chuckle: I'm sure it's a case of the OP lighting the blue touch paper and stepping back to see what happens. By the second page no one even knows what the original question was.

Good job guys, keep goingopcorn:


----------



## Rob S. (Nov 4, 2016)

borat52 said:


> Just re-read what you've written there, you appear to be under the impression that you can attain a higher top speed over a given distance with a lesser acceleration which is impossible.
> 
> At a stab your figures are not what one would expect due to the higher power causing traction issues, which effectively means you reach 30/60ft slower so you have to then make up the time over the rest of the run.
> 
> ...


Exactly. Its all about the horsepower, not the torque. 

There are several FBO E85 cars that make 600whp / 630wtq. These cars would get demolished by a upgraded turbo car that makes 720whp / 560wtq. I saw a video of exactly this. Wasn't even close anymore. If the 720whp car is in the right powerband it will kill the car with more torque but less bhp. This said, FBO E85 cars are no joke. If the upgraded turbo car was not in the right gear the outcome would be very different.


----------



## charles charlie (May 3, 2008)

These upgraded turbo cars have max torque further up the rev band that's why they will beat a lesser stage car.

Horsepower is a calculation based on torque value at a given rpm.

Those cars Dyno as a higher power because the torque remains high at higher rpm

It's incorrect to see it any other way.

For a car to make 720bhp with 560 lbsft of torque means it has to keep making that 560 at 6800 rpm.

For your example of a 600bhp and 630 lbsft torque car means it'll have to have 630 at 5000 rpm and then have that torque drop to 465 lbsft at 6800 rpm in order for the max horsepower to not exceed the 600 stated.

So you see it is always about torque as horsepower is calculated from it.


----------



## Rob S. (Nov 4, 2016)

charles charlie said:


> These upgraded turbo cars have max torque further up the rev band that's why they will beat a lesser stage car.
> 
> Horsepower is a calculation based on torque value at a given rpm.
> 
> ...


Where do i say that you are wrong? I am just saying that horsepower wins races, not torque.

The 720whp car will ALWAYS beat the 600whp car if its in the right powerband, no matter what the torque is.


----------



## dudersvr (May 7, 2003)

Rob S. said:


> Exactly. Its all about the horsepower, not the torque.
> 
> There are several FBO E85 cars that make 600whp / 630wtq. These cars would get demolished by a upgraded turbo car that makes 720whp / 560wtq. I saw a video of exactly this. Wasn't even close anymore. If the 720whp car is in the right powerband it will kill the car with more torque but less bhp. This said, FBO E85 cars are no joke. If the upgraded turbo car was not in the right gear the outcome would be very different.


If an FBO car on E85 car only makes 600hp the tuner needs his hands cutting off. My stock turbos made 640hp !!! On unleaded


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> If an FBO car on E85 car only makes 600hp the tuner needs his hands cutting off. My stock turbos made 640hp !!! On unleaded


I am obviously talking WHP lol. The FBO E85 cars make around 700bhp.


----------



## dudersvr (May 7, 2003)

Rob S. said:


> I am obviously talking WHP lol. The FBO E85 cars make around 700bhp.


My bad :bowdown1:


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> My bad :bowdown1:


No problem. Anyways. As soon as my car is finished i will post some vids, vbox numbers etc. Cant wait to drive the car again.


----------



## dudersvr (May 7, 2003)

Rob S. said:


> No problem. Anyways. As soon as my car is finished i will post some vids, vbox numbers etc. Cant wait to drive the car again.


You and me both dude, when is yours back?


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> You and me both dude, when is yours back?


Think it will take at least another 6 weeks. Had a front end accident so i'm still searching all the parts that i need the get the car back together


----------



## charles charlie (May 3, 2008)

What parts are you looking for Rob? I may have some front end bits around


----------



## Rob S. (Nov 4, 2016)

charles charlie said:


> What parts are you looking for Rob? I may have some front end bits around


I need a complete front end. Everything from the engine to the front bumper. So radiator support core, front bumper, hood, right fender, crash beam etc etc. If you have all of this please shoot me a message.


----------



## dudersvr (May 7, 2003)

Just had a call from engine builder and I need a new block, the car blew a rear main oil seal and no one has heard of this so I replaced it and noticed the pressure was giving strange readings so didnt drive it before taking it to AC, It sounded fine and had oil pressure. Got a call from AC to say crack found around the rear journal and a rod or rods bent as well.


----------



## motors (Mar 14, 2013)

dudersvr said:


> Just had a call from engine builder and I need a new block, the car blew a rear main oil seal and no one has heard of this so I replaced it and noticed the pressure was giving strange readings so didnt drive it before taking it to AC, It sounded fine and had oil pressure. Got a call from AC to say crack found around the rear journal and a rod or rods bent as well.


Sorry to hear you news, hope you can find a solution


----------



## dudersvr (May 7, 2003)

Solution is new block !!!!


----------



## terry lloyd (Feb 12, 2014)

Oh F*ck sorry to hear that mate - am sure i see someone was selling a forged engine ( built by SVM ) and it was at AC speed ? this was on ebay a couple of weeks ago


----------



## dudersvr (May 7, 2003)

terry lloyd said:


> Oh F*ck sorry to hear that mate - am sure i see someone was selling a forged engine ( built by SVM ) and it was at AC speed ? this was on ebay a couple of weeks ago


Yeah I got offered the whole car, I think a pal of mine bought the engine, I just need a block.


----------



## charles charlie (May 3, 2008)

dudersvr said:


> Yeah I got offered the whole car, I think a pal of mine bought the engine, I just need a block.


Oh shit luck John... 

Hope you find a block very very soon.


----------



## dudersvr (May 7, 2003)

charles charlie said:


> Oh shit luck John...
> 
> Hope you find a block very very soon.


Thanks Andy I might have found one, wonder why it cracked? I think the bent rods must have put it out of balance, I cant see the block twisting at such low power.


----------



## Tinyflier (Jun 13, 2012)

dudersvr said:


> Just had a call from engine builder and I need a new block, the car blew a rear main oil seal and no one has heard of this so I replaced it and noticed the pressure was giving strange readings so didnt drive it before taking it to AC, It sounded fine and had oil pressure. Got a call from AC to say crack found around the rear journal and a rod or rods bent as well.


John - sorry to hear this news. 

David


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> Thanks Andy I might have found one, wonder why it cracked? I think the bent rods must have put it out of balance, I cant see the block twisting at such low power.


Sorry to hear your news. You were on stock block stage 4.5?


----------



## charles charlie (May 3, 2008)

dudersvr said:


> Thanks Andy I might have found one, wonder why it cracked? I think the bent rods must have put it out of balance, I cant see the block twisting at such low power.


If it were bent rods then the journal bearings would show signs of uneven wear too, as would the internal surfaces of the piston and their corresponding bearings at the crank



Was it pistons 5 and 6 that were bent? If it is then that might explain the stresses of the uneven rotation being transferred to the rear journal bearing seats.


----------



## Chronos (Dec 2, 2013)

dudersvr said:


> Just had a call from engine builder and I need a new block, the car blew a rear main oil seal and no one has heard of this so I replaced it and noticed the pressure was giving strange readings so didnt drive it before taking it to AC, It sounded fine and had oil pressure. Got a call from AC to say crack found around the rear journal and a rod or rods bent as well.


Shit Shit luck man, your luck seems to getting on par with mine!

anyhow, Acspeed sourced my block so may be able to sort yours, if the one you have found yourself doesn't come through. good luck!


----------



## borat52 (Jan 29, 2006)

charles charlie said:


> These upgraded turbo cars have max torque further up the rev band that's why they will beat a lesser stage car.
> 
> Horsepower is a calculation based on torque value at a given rpm.
> 
> ...


Correct, but if I tell you my car makes 600lbft of torque you can't tell me the acceleration of the car. If I tell you it makes 600bhp you can tell me the acceleration of the car, which is why when people quote xlbft/ybhp it's the bhp number that tells you how fast it will accelerate and not the torque number.

The concept that "torque pulls" is also complete rubbish, power actually pulls.


----------



## Chronos (Dec 2, 2013)

borat52 said:


> The concept that "torque pulls" is also complete rubbish, power actually pulls.


So if BHP pulls, what does torque do? Pull. Think my heads starting to hurt, way above my pay grade this! haha.

ALL I care about, if the part thats snapping my neck off, when I press the loud pedal.. torque OR bhp,or simply both?... General consensus I think would be torque.


----------



## dudersvr (May 7, 2003)

Any google search will reveal the answer that HP is product of Torque

The mistake most people make when engaging in this debate is considering horsepower and torque independently. Almost everyone argues as if they are separate, unrelated values. They aren***8217;t.

Horsepower = (Torque x RPMs) / 5252
This equation is the second most important thing on this page, and it***8217;s the reason that anyone telling you that horsepower and torque should be considered equally and separately is significantly off-base. The fact of the matter is that horsepower is the product of torque and another value ***8212; RPMs (divided by 5252). It***8217;s not unrelated, separate, or different.

In fact, there***8217;s not a single machine in existence that measures a car***8217;s horsepower. It***8217;s a man-made number. When a car***8217;s performance is tested, its torque is measured using a dynamometer. The measure of an engine***8217;s performance is torque. Horsepower is an additional number that***8217;s attained by multiplying the torque by the RPMs

CONCLUSION

So a technical answer to the question of, ***8220;What makes acceleration: torque or horsepower?, is torque but torque at the wheels, not at the engine. And since were talking about torque at the wheels and not at the engine, the best answer is horsepower, because horsepower encompasses not only the engine's torqu but the total torque that gets delivered to the wheels and therefore provides the f in f = ma.


----------



## dudersvr (May 7, 2003)

Anyway heres the result of stage 4.5 on my block, rod pictures coming later


----------



## dudersvr (May 7, 2003)

charles charlie said:


> If it were bent rods then the journal bearings would show signs of uneven wear too, as would the internal surfaces of the piston and their corresponding bearings at the crank
> 
> 
> 
> Was it pistons 5 and 6 that were bent? If it is then that might explain the stresses of the uneven rotation being transferred to the rear journal bearing seats.


Exactly my thoughts Andy, but wondering whether to fit a billet ladder now, least I will do is ARP mainstud kit, I think this is caused by harmonics which means 
1) Bent rod (quite likely as I pushed the torque)
2) Harmonics (lot of time on limiter or car park anti lag heroics) I tend to short shift so dont really hit the limiter and dont do massive pops and bangs sessions to impress teenagers

So most likely down to bent rod causing the crank to be out of balance and wonder if it stretched the bearing cap bolts hence going ARP for caution.


----------



## e8_pack (Sep 22, 2013)

Sorry to hear that John. Think I'll definitely be going for rods in mine.


----------



## dudersvr (May 7, 2003)

Im thinking maybe a new block and crank then its as strong as I can make it.


----------



## Evo9lution (Aug 24, 2013)

Shit luck John. I hope that you're able to source a new / replacement block quickly.

Good luck!


----------



## T2 MSW (Feb 1, 2017)

Sorry to hear that dude, New block is not going to be cheap 

Better finding out now than it exploding in the engine bay and making an even bigger mess


----------



## dudersvr (May 7, 2003)

Yeah just my luck and just stumped up 4K for a clutch kit as well, doesnt rain it pours. Got a few options now but time is more important than money to a degree.


----------



## dudersvr (May 7, 2003)

T2 MSW said:


> Sorry to hear that dude, New block is not going to be cheap
> 
> Better finding out now than it exploding in the engine bay and making an even bigger mess


Yeah and at least it didn't destroy a head or heads.


----------



## charles charlie (May 3, 2008)

dudersvr said:


> Im thinking maybe a new block and crank then its as strong as I can make it.


I'd definitely not be reusing the old crank that's for sure.

What a royal pain in the arse matey. Yours is the first block that I've ever heard of that has has bent rods and block damage without being fully grenaded.

Just goes to show the Russian roulette of running more torque than stock.


----------



## Chronos (Dec 2, 2013)

dudersvr said:


> Yeah and at least it didn't destroy a head or heads.


Which is what happened to mine when it grenaded, thus even more cost. So you've been unlucky, but lucky in a respect, and *very* well spotted by acspeedtech as well! :clap: Imagine if forged/turbos, boost down the road and the crack then failed, that's a grenaded engine, double build and block you'd be paying for! :rotz:



charles charlie said:


> Just goes to show the Russian roulette of running more torque than stock.


YUP. If I'd realized the pain and hassle a blown engine is, parts time and $$$$. I'd have forged mine when I went to stage 4+


----------



## Evo9lution (Aug 24, 2013)

dudersvr said:


> Yeah just my luck and just stumped up 4K for a clutch kit as well, doesnt rain it pours. Got a few options now but time is more important than money to a degree.


Hope to see you and your car at The Supercar Event again John!


----------



## dudersvr (May 7, 2003)

Evo9lution said:


> Hope to see you and your car at The Supercar Event again John!


Looks like we can make that as can get a new block early May and that will just need boring/honing to pistons, everything else will be done, clutch, ETS, crank balanced etc.


----------



## dudersvr (May 7, 2003)

charles charlie said:


> I'd definitely not be reusing the old crank that's for sure.
> 
> What a royal pain in the arse matey. Yours is the first block that I've ever heard of that has has bent rods and block damage without being fully grenaded.
> 
> Just goes to show the Russian roulette of running more torque than stock.


If the crank is straight and doesnt need grinding and can be balanced do you still think its a liability?


----------



## dudersvr (May 7, 2003)

Bendy stock rod


----------



## dudersvr (May 7, 2003)

Rob S. said:


> Sorry to hear your news. You were on stock block stage 4.5?


Yes had a few drag runs after fitting the bb turbos, the rest was road work, last drag meet was Flame and Thunder and the seal did not leak until February. So not sure where it happened.


----------



## Chronos (Dec 2, 2013)

dudersvr said:


> Bendy stock rod


WOW! Wasn't far away from failure then! I've not seen an R35 bent rod before, normally it's just grenaded engines, as for obvious reasons people don't catch the bent rod in time to save the engine, it clearly shows what the higher torque from a stage 4+, is doing to the stock engine over time.


----------



## charles charlie (May 3, 2008)

dudersvr said:


> If the crank is straight and doesnt need grinding and can be balanced do you still think its a liability?


Can it be guaranteed to be 100% spinning true? Especially given something transferred enough stress to the cast block to cause a fracture and is it really possible to check that crank completely for micro fractures and being out of tolerance?

It's your call along with your engine builder but what I can say is if they say it's okay they sure as onions are onions wont guarantee it against failure! It'll be your money being gambled.


----------



## dudersvr (May 7, 2003)

charles charlie said:


> Can it be guaranteed to be 100% spinning true? Especially given something transferred enough stress to the cast block to cause a fracture and is it really possible to check that crank completely for micro fractures and being out of tolerance?
> 
> It's your call along with your engine builder but what I can say is if they say it's okay they sure as onions are onions wont guarantee it against failure! It'll be your money being gambled.


AC want to change it


----------



## charles charlie (May 3, 2008)

dudersvr said:


> AC want to change it


And for good reason. Very sensible.


----------



## dudersvr (May 7, 2003)

Ok Ok Ill change it


----------



## charles charlie (May 3, 2008)

dudersvr said:


> Ok Ok Ill change it


Sorry pal. :rotz:


----------



## borat52 (Jan 29, 2006)

dudersvr said:


> Bendy stock rod


That's my worst nightmare in a picture right there.


----------



## dudersvr (May 7, 2003)

borat52 said:


> That's my worst nightmare in a picture right there.


Im living it LOL


----------



## Tinyflier (Jun 13, 2012)

Immensely sorry that one of our own has had this failure but it completely vindicates the £6k or so spend in getting the forged components and balancing etc done.

While that alone cannot be a 100% guarantee of "never fail" it does give (me) piece of mind that I've taken all reasonable precautions and can fully use the Stage 4.25 horses/torque.

David


----------



## borat52 (Jan 29, 2006)

Chronos said:


> So if BHP pulls, what does torque do? Pull. Think my heads starting to hurt, way above my pay grade this! haha.
> 
> *ALL I care about, if the part thats snapping my neck off, when I press the loud pedal.. torque OR bhp,or simply both?... General consensus I think would be torque.*


The way you've put it there is actually the easiest way of explaining it. The acceleration is what 'snaps your neck off' and given a start speed with a certain kinetic energy and a higher target speed with a larger amount of kinetic energy the game is to increase the KE as quickly as possible as the faster you increase the KE the sooner you reach your target speed. Power is a measurement of energy transferred per unit time so it's power that snaps your neck.


----------



## Rob S. (Nov 4, 2016)

dudersvr said:


> Yes had a few drag runs after fitting the bb turbos, the rest was road work, last drag meet was Flame and Thunder and the seal did not leak until February. So not sure where it happened.


This is my worst nightmare. Really makes me think if i am doing the right thing to upgrade the turbo's on stock block. 

Who tuned your car if i may ask and do you possibly have a dyno to share?

Is it true that Litchfield and others give a warranty on their 4.5 builds up to 750bhp?


----------



## dudersvr (May 7, 2003)

Rob S. said:


> This is my worst nightmare. Really makes me think if i am doing the right thing to upgrade the turbo's on stock block.
> 
> Who tuned your car if i may ask and do you possibly have a dyno to share?
> 
> Is it true that Litchfield and others give a warranty on their 4.5 builds up to 750bhp?


It was Litchfield stage 4 when I got it, I then fitted an AC FMIC and Andy AC remapped it but was very adamant that torque was capped, I then fitted the BB turbos and again Andy mapped it but we added a race fuel map for drag, no dyno Im afraid all done from logs but calculations about fuel used and injector size plus the fact that the car the turbos come from was dynoed at I think 740hp and MAF was 80% maxxed mine was 99% maxed on the MAF and C16 and Andy reckons about 760/ and 640/50ft lbs


----------



## terry lloyd (Feb 12, 2014)

Chronos said:


> WOW! Wasn't far away from failure then! I've not seen an R35 bent rod before, normally it's just grenaded engines, as for obvious reasons people don't catch the bent rod in time to save the engine, it clearly shows what the higher torque from a stage 4+, is doing to the stock engine over time.


Loads more flex before they let go - apparently the piston was hitting the rod, it was rattling ( hence the strip down )


----------



## dudersvr (May 7, 2003)

Porsche 911 turbo do the same


----------



## Kieranrob (Apr 3, 2012)

I think I will be looking into forging my engine next winter! Am happy with the power my stage 4.25 makes but the thought of having a grenade under the bonnet scares me! 

Hope your back up and running soon


----------



## dudersvr (May 7, 2003)

Kieranrob said:


> I think I will be looking into forging my engine next winter! Am happy with the power my stage 4.25 makes but the thought of having a grenade under the bonnet scares me!
> 
> Hope your back up and running soon


Yup it will be, waiting on 2 short block prices if not new block and crank by first week of May


----------



## dudersvr (May 7, 2003)

Quick update, Ive bought a new block, crank , timing set, oil pump and Billet girdle. Should all be at AC middle of next week except girdle, that will follow soon. Also will be changing trans case and diff covers to billet as well when Trans is rebuilt.


----------



## charles charlie (May 3, 2008)

Time to start a build thread John...


----------



## Stealth69 (Jan 6, 2005)

eigh just caught up On this, that is shit luck dude, managed to catch it before it spat a rod through the block and still ended up having to replace everything anyway, gutted for you fella!! On the plus side she will be hard as a rock when you get her back!! 

Get the build thread going buddy when the bits arrive


----------



## dudersvr (May 7, 2003)

charles charlie said:


> Time to start a build thread John...


Will do


----------



## 55chev (Mar 4, 2015)

Why does everyone keep using the term im going to be Forging my engine soon,when the original rods and pistons are forged items stock.????? just wondered


----------



## terry lloyd (Feb 12, 2014)

55chev said:


> Why does everyone keep using the term im going to be Forging my engine soon,when the original rods and pistons are forged items stock.????? just wondered


Thought they were cast? (oem)


----------



## charles charlie (May 3, 2008)

OEM are cast.

Aftermarket are forged.

Somewhat irrelevant given the term "forged engine" has always meant replacing weaker stock rods and pistons with stronger aftermarket items.


----------



## 55chev (Mar 4, 2015)

Well i can see the rods are forged,from the picture,and wouldn't of thought they would put a cast piston in a turbo engine.


----------



## charles charlie (May 3, 2008)

Again, OEM are cast aluminium. 

Aftermarket are forged.

It's why they're stronger for similar weight.

http://www.motoiq.com/MagazineArtic...38/cosworth-r35-gt-r-vr38dett-components.aspx


----------



## dudersvr (May 7, 2003)

Stock rods ARE forged.........................from milk chocolate:flame:


----------



## charles charlie (May 3, 2008)

dudersvr said:


> Stock rods ARE forged.........................from milk chocolate:flame:


Everyone knows you pour cast chocolate John!


----------



## 55chev (Mar 4, 2015)

So both stock rods and pistons are forged items?


----------



## charles charlie (May 3, 2008)

No.

They're cast.

Aftermarket are forged.


----------



## Stealth69 (Jan 6, 2005)




----------



## charles charlie (May 3, 2008)




----------



## B'have (Dec 28, 2011)

You'd never see a bent rod if it were cast.


----------



## dudersvr (May 7, 2003)

B'have said:


> You'd never see a bent rod if it were cast.


Cast can bend to a degree, most suspension is cast yet ive seen dozens of parts bent in accidents, most wheels are cast but can be straightened.


----------



## dudersvr (May 7, 2003)

charles charlie said:


> Everyone knows you pour cast chocolate John!


These are cut from a large Billet Toblerone


----------



## e8_pack (Sep 22, 2013)

dudersvr said:


> These are cut from a large Billet Toblerone


Wouldn't happen with a Yorkie.


----------



## Stealth69 (Jan 6, 2005)

e8_pack said:


> Wouldn't happen with a Yorkie.


But then girls wouldn't be allowed to drive them!!


----------



## barry P. (May 9, 2010)

Stealth69 said:


> But then girls wouldn't be allowed to drive them!!


Are women allowed to drive gtrs? You learn something new everyday!


----------



## dudersvr (May 7, 2003)

opcorn:


----------



## charles charlie (May 3, 2008)

B'have said:


> You'd never see a bent rod if it were cast.


Lots of pictures posted on GTR forums of bent OEM cast rods.


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## Chronos (Dec 2, 2013)

terry lloyd said:


> Loads more flex before they let go - apparently the piston was hitting the rod, it was rattling ( hence the strip down )





B'have said:


> You'd never see a bent rod if it were cast.


stock R35 GTR cast bent rods *modded stage 4+ torque effect over time* (not mine)


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## charles charlie (May 3, 2008)

Easy to read explanation of why forged results in stronger material than simple casting.

here

And another good write up on the key material property differences between cast and forged here

Essentially casting is cheap and easy to mass produce. Forging is more time consuming and expensive but results in a stronger material due to grain alignment in the material structure which imparts fracture resistance (stress lines cannot propagate through compact structure) and ductility.


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## terry lloyd (Feb 12, 2014)

I am in the middle of mapping my own car at the minute and am doing quite a few data logs to get it right - apparently a little bit of knock is ok but i want zero knock in all conditions - it does make me wonder if people are blowing these engines due to not doing a data log every now and again just to check everything is ok - You wont know if the car is knocking until the boost gauge flashes or whatever warning Ecutek gives you - is this too late ( it has already happened ) on these engines that are probably on the limit at stage 4+ Also is the fueling right still ? lamdba sensors go off you could be running weak on one bank , they are designed to work in cats where the temps are hotter to keep them clean - many people run downpipes where they run cooler - then you have weather conditions which have quite a big impact on boost 

Just food for thought


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## Adamantium (Jun 24, 2002)

Just to be clear, are stock rods and pistons cast or forged?


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## terry lloyd (Feb 12, 2014)

Rods are cast 

Pistons are cast

http://www.streettunedmotorsports.com/parts/hks_gtr_r35_piston_rod_kit_21004_an016.htm


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## Adamantium (Jun 24, 2002)

Terry, you seriously didn't know I was joking?


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## terry lloyd (Feb 12, 2014)

I do now ...... put my mind at ease though as i was not 100% myself


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## Adamantium (Jun 24, 2002)

Can't think of many non supercars that have forged internals from the factory.

Annoying thing is it would save so much money if they let you spec it as a cost option - that said there's a huge difference between forged pistons. Massive gains can be had by iterative design improvements and testing.


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## terry lloyd (Feb 12, 2014)

I did read the MK2 focus RS had forged pistons also the 4x4 cosworth - thinking about it the oem Nissan runs quite low boost pressure so no need for expensive internals and they made them un tunable


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## Stealth69 (Jan 6, 2005)

Focus RS isn't forged I don't think.......

The STI7/8 was factory forged I think and some of the earlier STI's were forged or semi forged...... whatever the hell that means


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## TREG (May 20, 2004)

Stealth69 said:


> some of the earlier STI's were forged or semi forged...... whatever the hell that means



It means they were half hard and playful :tard:


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## charles charlie (May 3, 2008)

Ford stated a forged crank and lighter silicon aluminium pistons coated in graphite for the mk2 RS.

Whatever the **** that means I have no idea except that plenty of Mk2 RS owners replace those stock pistons. Even Mountune do an upgrade set.

That's gotta mean the stockies are not all that?

Also Sierra Sapphire had cast Mahle pistons.


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## Teaboy (Apr 24, 2016)

terry lloyd said:


> I am in the middle of mapping my own car at the minute and am doing quite a few data logs to get it right - apparently a little bit of knock is ok but i want zero knock in all conditions - it does make me wonder if people are blowing these engines due to not doing a data log every now and again just to check everything is ok - You wont know if the car is knocking until the boost gauge flashes or whatever warning Ecutek gives you - is this too late ( it has already happened ) on these engines that are probably on the limit at stage 4+ Also is the fueling right still ? lamdba sensors go off you could be running weak on one bank , they are designed to work in cats where the temps are hotter to keep them clean - many people run downpipes where they run cooler - then you have weather conditions which have quite a big impact on boost
> 
> Just food for thought


The stock ECU is capable of pulling up to 7 degrees of ignition timing out under it's active knock control strategy. I dose this before the onset of knock to prevent it. It also has the ability to + / - 25% on the fueling if it feels the trims are out. They are quite a forgiving ECU when it come to tuning and you would have to be so far off beam to be outside of it's correction capability. That being said in an ideal world you would not want to be reliant on the ECU constantly working to keep you safe so a good map should work perfect completely unaided. The very first bit of activity the knock sensors see is not actually knock rather the noise that comes before it. If you want to be 100% where the knock threshold is you will need to put a set of scopes / det cans on and have a listen.


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## terry lloyd (Feb 12, 2014)

I never got the phrase semi forged - either they are or not surely ?

Teaboy - i did not know that, i was under the impression that when it picks up knock it is actually det and reduces 1 degree then another degree until it detects none then puts the timing straight back in on a (cba) car - on a dba it puts the timing back in after a set amount of time, like you say if you have none on the logs you cant go wrong - i know about the closed loop set up for the STFTs but if you have a lambda sensor reading wrong the fueling will be wrong - Just saying imo its worth doing a log every now again to make sure everything is working as is - Why do i get the feeling you dont make the tea that often


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## e8_pack (Sep 22, 2013)

Christ. I don't want to be checking my car every 5 minutes, I just want it to work!


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## Stealth69 (Jan 6, 2005)

e8_pack said:


> Christ. I don't want to be checking my car every 5 minutes, I just want it to work!


Go buy a german car then lol


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## e8_pack (Sep 22, 2013)

Stealth69 said:


> Go buy a german car then lol


I've got one already, cheers.


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## Stealth69 (Jan 6, 2005)

e8_pack said:


> I've got one already, cheers.


I'd stick with it then LOL  Nice 996


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## Adamantium (Jun 24, 2002)

I think semi forged is referring to hypereutectic pistons.


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## Stealth69 (Jan 6, 2005)

Adamantium said:


> I think semi forged is referring to hypereutectic pistons.


Brilliant something else I need to google


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## Adamantium (Jun 24, 2002)

I wouldn't worry about it, you'd never buy them if building an engine.


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## e8_pack (Sep 22, 2013)

Viper's pre 2000 had forged pistons, they moved to hypereutectic and made more power, but had less scope for modification.

If believe there is a higher silicone content so have less thermal expansion and can be made to tighter tolerances. However they are more brittle and dont take well to modification.


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## dudersvr (May 7, 2003)

terry lloyd said:


> I am in the middle of mapping my own car at the minute and am doing quite a few data logs to get it right - apparently a little bit of knock is ok but i want zero knock in all conditions - it does make me wonder if people are blowing these engines due to not doing a data log every now and again just to check everything is ok - You wont know if the car is knocking until the boost gauge flashes or whatever warning Ecutek gives you - is this too late ( it has already happened ) on these engines that are probably on the limit at stage 4+ Also is the fueling right still ? lamdba sensors go off you could be running weak on one bank , they are designed to work in cats where the temps are hotter to keep them clean - many people run downpipes where they run cooler - then you have weather conditions which have quite a big impact on boost
> 
> Just food for thought


Mine was logged all the time and checked


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## T2 MSW (Feb 1, 2017)

dudersvr said:


> Mine was logged all the time and checked


come on where is your build thread


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## dudersvr (May 7, 2003)

T2 MSW said:


> come on where is your build thread


In Austria with my new block. Ill get pics sorted when it gets back underway and when I carry it on after getting car back from AC as I have a few bits to fit of my own.


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