# Gtr stage 5 conversion



## amc (Mar 9, 2015)

hi guys any reveiws or problems on stage 5 conversion on stock internals 750 bhp


----------



## Fashraf (Dec 3, 2013)

3000 miles on mine and so far no problems, in hindsight i would have done the con rods...only regret


----------



## paulmc (Oct 31, 2004)

Not many on here run over 700bhp on standard bottom end. US guys seem to be happy to do it though.

mine will be around 800bhp standard bottom end once I get it back on the road. Torque will be capped at 630lbs


----------



## amc (Mar 9, 2015)

Fashraf said:


> 3000 miles on mine and so far no problems, in hindsight i would have done the con rods...only regret


how do u drive it thanks


----------



## amc (Mar 9, 2015)

paulmc said:


> Not many on here run over 700bhp on standard bottom end. US guys seem to be happy to do it though.
> 
> mine will be around 800bhp standard bottom end once I get it back on the road. Torque will be capped at 630lbs


800bhp not to much for standard rods


----------



## paulmc (Oct 31, 2004)

Torque and revs kill rods. The rods can cant take more than 690lbs (tested in US) for any length of time, where as they seem to be ok around 650lbs.

I intend to run 630lbs to 7000RPM so should make around 800 ish bhp


----------



## Takamo (Oct 18, 2005)

My stage 5 is pushing a healthy 772bhp with 690.2lb of torque on Litchfields dyno before you all start jumping up and down... Lol


----------



## Chronos (Dec 2, 2013)

Takamo said:


> My stage 5 is pushing a healthy 772bhp with 690.2lb of torque on Litchfields dyno before you all start jumping up and down... Lol


690 you say?? should I stop jumping yeT?? lol Is yours rod jobbed? or are litchfields Dyno's different somehow


----------



## Tariq (Mar 24, 2008)

amc said:


> hi guys any reveiws or problems on stage 5 conversion on stock internals 750 bhp


Not sure if its with all stage 5,s, but i get a nasty smell of fuel in the cabin.

Not the kind you get from down pipes.

Taken it back to have it checked but they cant find anything wrong.

All seals been replaced, still smells.

T


----------



## Fashraf (Dec 3, 2013)

Tariq said:


> Not sure if its with all stage 5,s, but i get a nasty smell of fuel in the cabin.
> 
> Not the kind you get from down pipes.
> 
> ...


Tariq, i get the same after a hard drive or morning start, seems to be normal i suppose


----------



## Fashraf (Dec 3, 2013)

amc said:


> how do u drive it thanks


I drive pretty hard finding myself at 6000/7000 rpm constantly, its hard not to 
btw my torque is also capped at 620


----------



## jasonb (Jan 15, 2013)

I'm running over 800hp and 630 torque on standard engine, it's all good.


----------



## amc (Mar 9, 2015)

Fashraf said:


> 3000 miles on mine and so far no problems, in hindsight i would have done the con rods...only regret


Who done your conversion thanks


----------



## amc (Mar 9, 2015)

jasonb said:


> I'm running over 800hp and 630 torque on standard engine, it's all good.


How many miles u done and who converted it thanks


----------



## amc (Mar 9, 2015)

jasonb said:


> I'm running over 800hp and 630 torque on standard engine, it's all good.


Mine has chucked a rod out the block at 600 torq and 778 horse power why I ask


----------



## Takamo (Oct 18, 2005)

Chronos said:


> 690 you say?? should I stop jumping yeT?? lol Is yours rod jobbed? or are litchfields Dyno's different somehow


Yes I do say, I had it dyno'd at MSL PERFORMANCE on there Dynojet dyno and many guys were saying that dyno Jet figures were not accurate, so I had it dyno'd at Litchfields and it made 807.8bhp with 699.5lb of torque then iain detuned it slightly so it will be safe, then it made 772bhp and 690.2lb of torque. :chuckle::chuckle:


----------



## Chronos (Dec 2, 2013)

amc said:


> Mine has chucked a rod out the block at 600 torq and 778 horse power why I ask





Takamo said:


> Yes I do say, I had it dyno'd at MSL PERFORMANCE on there Dynojet dyno and many guys were saying that dyno Jet figures were not accurate, so I had it dyno'd at Litchfields and it made 807.8bhp with 699.5lb of torque then iain detuned it slightly so it will be safe, then it made 772bhp and 690.2lb of torque. :chuckle::chuckle:


Indeed you do say, so litchfields are happy to tune a stock engine to 690Lbft of torque, and for that to be safe, cool I will book mine in tomorrow. :thumbsup:


----------



## w8pmc (Sep 16, 2010)

Chronos said:


> Indeed you do say, so litchfields are happy to tune a stock engine to 690Lbft of torque, and for that to be safe, cool I will book mine in tomorrow. :thumbsup:


:chuckle:


----------



## Tariq (Mar 24, 2008)

Chronos said:


> Indeed you do say, so litchfields are happy to tune a stock engine to 690Lbft of torque, and for that to be safe, cool I will book mine in tomorrow. :thumbsup:


Mines came out off Litchfields with 757/730 (Surrey rolling road).

Went back after a couple of months when the Maha was up and running and they turned the volume down to 765/640 

What a difference, completely different car now.

T


----------



## nimz (Oct 27, 2007)

Think 650ftlb is about max safe, 7000rpm is a bit close to the limit of the rods from what I've seen so as long as you don't bounce off the limiter should be fine.
What do the stock clutches cope with?
Thinking about stage 5 too :smokin:


----------



## Chronos (Dec 2, 2013)

Tariq said:


> Mines came out off Litchfields with 757/730 (Surrey rolling road).
> Went back after a couple of months when the Maha was up and running and they turned the volume down to 765/640
> What a difference, completely different car now.
> T


so thats kind the of the torque difference between a forged engine power, and non forged that would be normally capped around +- 650lbft torque

how much difference did you find car with the 90lbft torque more? when it was at 730?

I've been wondering this, as is it worth the extra like 4-5k for the engine rods/forge to gain the torque to match the bhp?

thanks

Chron


----------



## Tariq (Mar 24, 2008)

Chronos said:


> so thats kind the of the torque difference between a forged engine power, and non forged that would be normally capped around +- 650lbft torque
> 
> how much difference did you find car with the 90lbft torque more? when it was at 730?
> 
> ...


A huge difference, so much of a difference that i will be having the engine upgraded on the next service .

T


----------



## jasonb (Jan 15, 2013)

Litchfield has done mine, I was going to go for extra torque, but it struggles to grip now, plus you would need to do gearbox and clutches to make use of extra torque.


----------



## amc (Mar 9, 2015)

Can any 1 advise me thoughts on why mine has snapped a rod with 600'torq 778 bhp when there's loads on here with lot more torq


----------



## AdnanK (Jun 11, 2013)

amc said:


> Can any 1 advise me thoughts on why mine has snapped a rod with 600'torq 778 bhp when there's loads on here with lot more torq


Bad tune/Mechanical defect/Improper use/Bad luck

Pick one.


----------



## paulmc (Oct 31, 2004)

amc said:


> Can any 1 advise me thoughts on why mine has snapped a rod with 600'torq 778 bhp when there's loads on here with lot more torq


How did you confirm you are running 600lbs and 778?

Det will wreck your rods. 

What turbos you running? aftermarket intercooler? what exhuast? how do you drive it? using low revs and high load puts most strain on everything.

needs more info, prob wont know until you get them engine stripped down to have a look


----------



## Adamantium (Jun 24, 2002)

Takamo,

Don't think Litchfield would release a stock engine with 690lbft under warranty. Something doesn't sound right there.


----------



## r32r33r34r35 (Jan 17, 2011)

I'm running 802hp with 681 torque on a stage 5. Still running stock internals. Dyno'd at Litchfields


----------



## Takamo (Oct 18, 2005)

Adamantium said:


> Takamo,
> 
> Don't think Litchfield would release a stock engine with 690lbft under warranty. Something doesn't sound right there.


Yes they did and I'll stick the graph up later on and it's still covered by Litchfields warranty.


----------



## Jonndogg (Oct 27, 2012)

Wow thats amazing of Litchfields to warrant that spec if true. I should have nothing to be worried about with stage 4.25 then!


----------



## amc (Mar 9, 2015)

paulmc said:


> How did you confirm you are running 600lbs and 778?
> 
> Det will wreck your rods.
> 
> ...


ac speed tech stage 5 turbos russ fellows exhaust ams cooler was pretty low gears when exploded any sugestions


----------



## amc (Mar 9, 2015)

amc said:


> ac speed tech stage 5 turbos russ fellows exhaust ams cooler was pretty low gears when exploded any sugestions


dynod to show power thanks


----------



## paulmc (Oct 31, 2004)

you wont know until you rip the heads off if it was det or not.

high load low speed puts most strain on the engine. low gears high revs is probably easier on the car until you go up over 6500rpm

How many miles on your car?? prob just bad luck

pic attached of extreme DET (my kart engine). You are looking for small pinhead spots on the piston tops


----------



## gtr mart (Mar 29, 2004)

That's a new level of tune from Andy, I imagine he is quite concerned? What is he doing about it?


----------



## amc (Mar 9, 2015)

gtr mart said:


> That's a new level of tune from Andy, I imagine he is quite concerned? What is he doing about it?


its his 750 package just made bit more power thats all he is concerned cairnt understand why its done


----------



## ACspeedtech (Aug 25, 2011)

Last dyno plot for this car below, capped under 620ftlb, boost control within 0.1 bar max overswing. 629hp at the tyres, 1.15-1.55bar ramped. 6th set of our own turbos however used many other brands in the past.


----------



## paulmc (Oct 31, 2004)

Thats not big power really. nice flat torque curve Looks good. Wonder what failed??


----------



## gtr mart (Mar 29, 2004)

That looks like 625lbft at the wheels. Would this not equate to 675 / 690lbft at the fly?

Absolute gutter it has happened though!


----------



## ACspeedtech (Aug 25, 2011)

That's around 620 peak flywheel torque, the power figure is at the tyres so people can make whatever flywheel estimation they are happy with.
It does appear to be rod failure by the sounds of it, but we're within safe limits on torque and running less torque than the stage 4.25 it previously was. I don't believe it failed under high engine load conditions.
The knock control was fully active and if it was having to retard an amount of the 8 capable it would have flashed the engine light to warn the driver it was having to do something to stay safe.
Hopefully when the engine is stripped/ecu data recalled it'll be apparent. Certainly of major concern to me, and we'll work to getting back on the road soon.


----------



## paulmc (Oct 31, 2004)

is there any rhyme or reason behind these failures?? I guess there has got to be but finding it wont be easy.

I read somewhere litchfield has had 3 failures over the years and Switzer had had similar failures. then again loads of cars are running this type of power with no issues.

Is it a combination of things?

Too much boost
Too much heat
Too much torque low down
Too many miles
dodgy fuel every now and again
very slight knock from time to time
lack of adequate airflow
or just unlucky??

that list is not directed at anyone just thinking out loud

then why can a 650 + lbs car run for what seems forever where as a 620lbs car with higher power upto fail. Is it the increased ability to accelerate the engine due to increased power?? would it be that simple??

I have seen a few kart engine failures with guys revving them too hard on the stand. The engine cant cope with the acceleration forces enduced when the wheels are off the ground. BANG

Who knows, hope you get to the botom of the failure. All info is good info, even though you will both be in a bit of pain at the moment!!


----------



## amc (Mar 9, 2015)

paulmc said:


> is there any rhyme or reason behind these failures?? I guess there has got to be but finding it wont be easy.
> 
> I read somewhere litchfield has had 3 failures over the years and Switzer had had similar failures. then again loads of cars are running this type of power with no issues.
> 
> ...


Clearly to much power for stock rods proven on my car gutted not even 300 miles


----------



## paulmc (Oct 31, 2004)

Wow 300 miles is not good. you must be gutted!!!


----------



## terry lloyd (Feb 12, 2014)

Pauls thinking hmmm maybe i should have put rods in mine after all lol


----------



## paulmc (Oct 31, 2004)

terry lloyd said:


> Pauls thinking hmmm maybe i should have put rods in mine after all lol


yeah i am getting worried too


----------



## amc (Mar 9, 2015)

paulmc said:


> yeah i am getting worried too


I would advise you to upgrade your rods mine roded it self in first gear and you no as well as me it couldn't even be on full boost in first gear worry ing what power is yours running


----------



## paulmc (Oct 31, 2004)

too late engine back in with bigger turbos. Will run 800bhp

Good read here

http://www.gtr.co.uk/forum/134004-my-engine-went-pop-today-r35-gtr-20.html


----------



## AdnanK (Jun 11, 2013)

Aren't there some stage 2's running 600-620 Lb ft, wasn't that deemed as safe?

I always wondered why Nissan only up'd the torque very slightly from 09-14 models where as the BHP has gone from 485-550, maybe the stock engine is pushing it with the supposedly safe 600 Lb ft figure?


----------



## paulmc (Oct 31, 2004)

and the new Nismo still runs limited torque (480lbs) maybe something in it??

Stage 2 - 4 is around 600lbs


----------



## AdnanK (Jun 11, 2013)

paulmc said:


> and the new Nismo still runs limited torque (480lbs) maybe something in it??
> 
> Stage 2 - 4 is around 600lbs


Exactly, if it was safe, why didn't Nissan increase the Torque in the same increments as it did with the BHP from 09 all the way to Nismo's 590 BHP?

Here are some figures

09 GTR 485 HP 430 lb ft
Nismon 595 HP 460 lb ft

Nissan seems cautious with upping the Torque.


----------



## Anders_R35 (Jul 20, 2011)

I think it's luck of draw. We know these rods aren't produced to same standard as aftermarket forged ones. Hypothetically speaking what if 1/4 of 1% have a defect. On 1000 engines (6000 rods) that's 15 rods with a possible lurking problem. That could be 15 engines within 1000 cars if the defect rods end up in different engines, or 1.5% of cars.

Now take stock power from base engine 485bhp / 430lbft, add 54% power hike and 40% increase in torque to reach 750bhp / 600lbft. If you're the unlucky one with defect rod the increased power could push it over edge. Or bad batch of fuel some det, bang.

May be the defect rod would last at stock power, maybe not. I read a thread on GTRlife where stock motor threw a rod, so it can happen.

Anders


----------



## AdnanK (Jun 11, 2013)

Some of the ones in the US weren't caused by Det, they were caused by excessive Torque which bent the rods. 

It may be a bad batch etc but Nissan seems to play it safe with the torque numbers on these motors.


----------



## Timboy666 (Mar 7, 2014)

AdnanK said:


> Exactly, if it was safe, why didn't Nissan increase the Torque in the same increments as it did with the BHP from 09 all the way to Nismo's 590 BHP?
> 
> Here are some figures
> 
> ...


I think you have to remember that maybe they don't increase the Torque because ultimately they are producing a car that has to be driveable by anyone increasing Torque makes the car more undrivable for a non-skilled person!!


----------



## terry lloyd (Feb 12, 2014)

Cannot remember where i read it but a tuner in usa was saying when changing a few cars from full bolt on tunes to forged engines the oem rods were bent (over time they were bending )


----------



## EAndy (Dec 13, 2011)

Terry it's a link from the link above I read it last night.

They said they had 25 UK engines shipped to the US for recall and had some photos of the rods that were bent (usually number 3 and 4). 

I think Anders is right though it's really luck of the draw to a certain aspect, sure if you go put 800 lb-ft through them they'll bend but around 550 - 640 I think it's luck.


----------



## amc (Mar 9, 2015)

EAndy said:


> Terry it's a link from the link above I read it last night.
> 
> They said they had 25 UK engines shipped to the US for recall and had some photos of the rods that were bent (usually number 3 and 4).
> 
> I think Anders is right though it's really luck of the draw to a certain aspect, sure if you go put 800 lb-ft through them they'll bend but around 550 - 640 WHATS YOUR THOUGHTS ON WHAT THE TUNER SHOULD DO ABOUT THIS WHEN WAS CLEARLY STATED TO ME THE RODS WOULD BE FINE AT 600 TORQ LESS STRESS ON MOTOR THAN THE STAGE 4 625BHP IT WAS RUNNING


----------



## amc (Mar 9, 2015)

amc said:


> EAndy said:
> 
> 
> > Terry it's a link from the link above I read it last night.
> ...


----------



## gtr mart (Mar 29, 2004)

for a failure to occour 300 miles after conversion, it would suggest something was wrong with the tune in one way or another and as such I would be looking for some pretty serious assistance.


----------



## TomS (Mar 21, 2012)

gtr mart said:


> for a failure to occour 300 miles after conversion, it would suggest something was wrong with the tune in one way or another and as such I would be looking for some pretty serious assistance.


But then the other side of the coin is that the car was re-tuned to run lower torque so the damage could already have been done by previously running higher torque. Regardless of whether it was re-tuned or not, the failure was going to occur as the part was already damaged and it was just a matter of time, which would have happened sooner than 300 miles if the previous map had been kept.

Difficult one though, hope it all works out for you though


----------



## charles charlie (May 3, 2008)

gtr mart said:


> for a failure to occour 300 miles after conversion, it would suggest something was wrong with the tune in one way or another and as such I would be looking for some pretty serious assistance.


Can't say I agree with that.

Failure through fatigue is not a single on off event but cyclic in nature. These rods will have been getting stressed for a long while before they went. It's the nature of the material they're made from.

All of use who tune our cars are rolling the dice every time we apply throttle. The higher the torque output, the higher the internal stresses and thus the higher the risk of failure.

It's wrong IMHO to say that 680 lbsft isnt safe but 610 is. One is just more likely to fail than the other by a certain %. There is no line that below is safe and above is dangerous, it's a graph of increasing risk.

To the OP I feel for you, it could have happened to any of us at any time, and it's worth remembering that.

IMHO I believe Nissan capped torque simply to reduce the need to strengthen other parts of the drivetrain. Transmission in particular.


----------



## amc (Mar 9, 2015)

TomS said:


> But then the other side of the coin is that the car was re-tuned to run lower torque so the damage could already have been done by previously running higher torque. Regardless of whether it was re-tuned or not, the failure was going to occur as the part was already damaged and it was just a matter of time, which would have happened sooner than 300 miles if the previous map had been kept.
> 
> Difficult one though, hope it all works out for you though


car was running same torq level at stage 4 620torq 620 bhp


----------



## terry lloyd (Feb 12, 2014)

Totally agree with the Charles

Thought this was a interesting quote from AMS TUNING 

I don't recommend running the stock turbos on the stock motor at 600whp as you might as well replace the turbos with a flame thrower. But 650whp on our upgraded turbos is very safe with the stock tune. It's all relative to the parts and tuning you put behind it.


----------



## EAndy (Dec 13, 2011)

amc said:


> WHATS YOUR THOUGHTS ON WHAT THE TUNER SHOULD DO ABOUT THIS WHEN WAS CLEARLY STATED TO ME THE RODS WOULD BE FINE AT 600 TORQ LESS STRESS ON MOTOR THAN THE STAGE 4 625BHP IT WAS RUNNING


I would exercise the rights of my warranty from my tuner to rectify the issue if your asking on an individual basis. My tuner believes this is safe and they happily warranty my car as I allow them to maintain the upkeep of the car and know it's history. 

But Stage 4.25 over 15,000 miles of fast road, Nurburg and track days with 620 ft-lb torque I've had to date no issues.

As said I believe it's either bad luck or perhaps a bad tune. I would imagine (and it's guess work) 95% of tuned cars running 550 - 640 torque haven't had issues. The more power you push through OEM the higher level of stress its a dice you roll I think.


----------



## gtr mart (Mar 29, 2004)

I agree that there is an element of luck of the draw, but it goes back to the height of skyline popularity where you might pay £20k for an engine rebuild, drive it down the road and it implodes which is then sited as bad luck with no recourse. When things brake that close to having been done or worked on, there is always going to be a question mark for me.


----------



## AdnanK (Jun 11, 2013)

For peace of mind, If you want 600+ Lb ft of torque on the stock motor then get it done by a Tuner who also provides a warranty for the work.


----------



## Adamantium (Jun 24, 2002)

charles charlie said:


> Can't say I agree with that.
> 
> Failure through fatigue is not a single on off event but cyclic in nature. These rods will have been getting stressed for a long while before they went. It's the nature of the material they're made from.
> 
> ...


Totally agree with this.

So many people look for a magic number, clearly failing to grasp the above.


----------



## ACspeedtech (Aug 25, 2011)

amc said:


> mine roded it self in first gear and you no as well as me it couldn't even be on full boost in first gear


As I mentioned in my previous post, I don't believe this failure occurred due to high engine load conditions.
I posted the dyno plot of this car which subsequently had a degree of timing and 0.05 bar removed from the map before collection as it was comfortably over the advertised figure for this package.
Datalogs are still saved on my laptop from the tuning on this car.

Torque levels at this level of tune are less than the hundreds of stock turbo stage '1' to '4.25' we've tuned over the years. There are a well represented amount of cases of engine failure which are not necessarily down to the power/torque output. This car had been tuned previously by other companies and running stage '4.25' before we worked on it. It ran on factory service intervals as far as I am aware, but also had run on trackdays. There are other question marks over the condition of this engine prior to this failure too.

As yet, we have not seen the car to confirm what has actually failed or had chance to diagnose or pull ECU data. When we get the chance to do this, I hope to be able to shed some light on this matter.


----------



## amc (Mar 9, 2015)

Many tuners is stating to much power for standard rods I wish I had just listened now and went with forged like my original plans


----------



## amc (Mar 9, 2015)

Car done 1 track day on really low boost seting as didn't have the cooler on it at the time


----------



## charles charlie (May 3, 2008)

Did you buy the car new or second hand?

If second hand then do you know its complete history with regards previous tuning and track history?


----------



## amc (Mar 9, 2015)

Second hand car was standard when I got it low miles previous owner was doctor meticulous service record real nice looked after example I searched for the best I could find to build a nice car


----------



## charles charlie (May 3, 2008)

But the car was already tuned for you by somebody else prior to taking it to ACSpeedtech?


----------



## nimz (Oct 27, 2007)

amc what exactly happend in 1st gear? Did you launch it because I have always worried about launching mine and never had the balls to try it.


----------



## amc (Mar 9, 2015)

Never launched it just pulled away from junction in first gear


----------



## paulmc (Oct 31, 2004)

Any update, engine stripped yet?


----------



## TomS (Mar 21, 2012)

Any news on what the issue was as I've noticed you have another thread about a Jurgen 850 build so I assume this has been sorted?


----------

