# How far on a stock engine and gearbox?



## DocT (Dec 17, 2014)

Last couple of weeks I've had the pleasure of driving on some of the best roads in the UK in a convoy with some great cars including 488 GTB and 675LT. I've now realised I need more power to keep up with these guys  It's a self perpetuating cycle but after 18 months of the current power I think I'm due an upgrade soon.

Currently my car is a Stage 4.25 with 102mm exhaust, AMS intercooler and V5 Ecutek running 680 bhp and torque capped to 615lb/ft on the Litchfield dyno.

I think a turbo upgrade is next but I'm just wondering what kind of headline power figure can I expect from a stock engine and gearbox (magnets and circlips done). I would want to keep the torque capped to under 650 lb/ft.

Considering bhp is a by product of torque, is it even possible to get 800+ bhp with the torque capped under 650 lb/ft on a VR38 and standard rev limit?


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## charles charlie (May 3, 2008)

Utterly pointless spending on bigger turbos to cap the torque IMHO.

Why drop the engine and not future proof and protect from a grenaded engine?


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## DocT (Dec 17, 2014)

Purely from a cost perspective. I would like to eventually have it in the 900+ bhp range but can't afford all the associated costs in one hit. 

Plan is to do a turbo and manifold upgrade this year with limited torque. Once finances allow engine and gearbox upgrades to get the most out of the turbo upgrade.


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## DocT (Dec 17, 2014)

I think I might have found the answer to my own question.

http://www.gtr.co.uk/forum/320257-litchfield-stage-5-a.html

Would be interested to hear from others running the above set up.


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## Johnny G (Aug 10, 2012)

Torque on the stock turbos starts to drop off at 5200rpm, give or take. This is where the aftermarket ones would start to come into their own.
If you cap to 630lb/ft to a 7200rpm limit, you'll have 860bhp, give or take.
Stock turbos can't produce more than 480lb/ft at 7200rpm, which is 658bhp, so this is where you will gain.


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## vxrcymru (Sep 29, 2009)

I've been running 800bhp and 657ftlbs on a stock engine and box for some 20k miles with 3 track days, so far so good. They are GT28 turbos running 1.5 bar at peak power.


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## Aldogtr (Jan 10, 2016)

Get the engine built then go from there


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## DocT (Dec 17, 2014)

Aldogtr said:


> Get the engine built then go from there


Apart from theoretical reliability am I going to gain anything from rods + pistons if I just have to cap the torque to protect the gearbox? 

Will I get a noticeable gain in performance by upgrading the turbos and capping the torque? From the sounds of it yes.


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## Econ (Jun 8, 2006)

I just bought a 2010 Stage 5 car but only had it a couple of weeks. It's running 776 BHP and so far so good but currently, I am running it on lower boost until I get used to it and I am slowly increasing it every couple of weeks.

When I was sharing the car here a few had heard of Litchfield stg5's warping rods etc but I think there's a few stg 5's running around so my guess at the moment is if you look after the car then it should be fine.


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## charles charlie (May 3, 2008)

Econ said:


> I just bought a 2010 Stage 5 car but only had it a couple of weeks. It's running 776 BHP and so far so good but currently, I am running it on lower boost until I get used to it and I am slowly increasing it every couple of weeks.
> 
> When I was sharing the car here a few had heard of Litchfield stg5's warping rods etc but I think there's a few stg 5's running around so my guess at the moment is if you look after the car then it should be fine.


If only it was that simple.

There are plenty of standard cars that have bent rods, most catastrophically, and when we increase the power we increase the risk of this happening.

As Johnny says you will get more headline bhp, higher up the rpm range when you fit aftermarket turbos, but for me limiting torque somewhat limits the benefit of spending all that money dropping the engine and fitting them in the first place.

Rods and pistons are around teh same cost as the turbos but the labour of dropping the engine is already covered so imho I'd be doing them at the same time.

As ever it's personal choice and dependant on the risks you're willing to take but given the cost of replacing the block, I'd never do turbos without rods at least.


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## rob2005 (Apr 26, 2015)

opcorn:
Rods are being thrown left right and centre and the moment with at least 7 cars in the last few weeks that I know of through Batallion.

Anything over Stage 4.25 if you drive it hard will need forging other wise its only a matter of time before a Rod says hello.

There are some like VXR above who have been fine for 20k miles but he may be more mechanically sympathetic and follow strict warm up and cool down procedures and only use Full boost now and again.

If your hard on your car and less sympathetic you'll do rods in no time, plus if your going 800 bhp on a budget something will go. 

I just cant see how people need over Stage 4.25 for fast road driving, im no Schui but can drive a car and its crazy power for the road even my peasly 670bhp!! Cant remember the last time I used the power constantly on full boost.

Brakes and suspension coupled with a good Geo set up would be my first port of call before going all out on the engine.

Each to our own though, this is why I love GTR


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## grahamc (Oct 1, 2006)

Why not spend the money on the handling? 
-suspension
-front diff
-weight reduction

Significant gains to be made and a LOT less risk!


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## Evo9lution (Aug 24, 2013)

If you're going to drop the engine for anything, do the front diff at the same time and save most of the labour cost ...

For me personally, if I forge the engine I would feel that I could drive harder and for longer. If I did the turbos without the engine, I'd be waiting for something to go pop. So, I would find Stage 4.25 performance with no concerns much more entertaining than 800 BHP with a constant nagging worry ...


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## terry lloyd (Feb 12, 2014)

I do wonder if bigger turbo`s are easier on the the Rods ( cooler charge temp ) lower psi to get the same power lower down and ramp up near the top end, also are these cars throwing rods if a good intercooler is fitted lower cooler charge temp again - it maybe the case that a well set up stage 5 car is safer than a 4.25 as the oem turbos give off a lot of heat making 18psi

Not done it myself but apparently you only need to drop the engine 12" to change the turbos - ie: undo subframe and jack the car up


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## DocT (Dec 17, 2014)

grahamc said:


> Why not spend the money on the handling?
> -suspension
> -front diff
> -weight reduction
> ...


Already have the Litchfield suspension kit which is a significant improvement for my use over stock.

What are the main benefits of a front diff for road use? Some might say there's no point of more power for road use but as I explained I have a couple of friends which walk away on road/track so I guess my options are either to stay at home or get more power.

I'm only 75kg and about 10% body fat so not much else to loose :chuckle:

(I don't really want to compromise the GT ability of the car, if anything I'd like to add more weight with Dynamat and a better trimmed interior in the future).

I can understand the reliability worries but isn't what I'm suggesting a Stage 5 equivalent? Litchfield have obviously carried out a lot of these conversions so I'm a little surprised with the levels of caution at doing a turbo upgrade on a stock engine.

I always practice plenty of mechanical sympathy, generally 10 miles before using boost and 3-4 miles off boost cruising after a hard drive before parking up.


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## AdnanK (Jun 11, 2013)

terry lloyd said:


> I do wonder if bigger turbo`s are easier on the the Rods ( cooler charge temp ) lower psi to get the same power lower down and ramp up near the top end, also are these cars throwing rods if a good intercooler is fitted lower cooler charge temp again - it maybe the case that a well set up stage 5 car is safer than a 4.25 as the oem turbos give off a lot of heat making 18psi
> 
> Not done it myself but apparently you only need to drop the engine 12" to change the turbos - ie: undo subframe and jack the car up


Cooler temps and better flowing turbos etc would only result in more power being produced efficiently, but it's the 200+ lbft gain in torque over stock that bends these rods. I also understand driving style are a big factor too.

As mentioned before, I know of a MY14 Stage 5 car with all supporting mods bend rods, owner was lucky as it was going in for a forged engine.


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## grahamc (Oct 1, 2006)

DocT said:


> Already have the Litchfield suspension kit which is a significant improvement for my use over stock.
> 
> What are the main benefits of a front diff for road use? Some might say there's no point of more power for road use but as I explained I have a couple of friends which walk away on road/track so I guess my options are either to stay at home or get more power.
> 
> ...


or learn to drive better opcorn: 






:runaway: sorry had to be said  

Ferrari 1,544 kg, 661hp, 7 speed
Macca 1,358 kg, 666hp, 7 speed
GTR 1,740 kg, 680hp, 6 speed

Both of them have carbon ceramic brake setups as well, similar power and at least 200kgs lighter.......... my list would be:-

lightweight wheels
lightweight brake setup 
lightweight seats
front diff (https://shop.quaife.co.uk/nissan-r35-gt-r-quaife-atb-helical-lsd-differential)

My worry with stage 5 is then the added stress on the gearbox and clutches. Once you go beyond stage 4.25 you really need to do everything, so turbos, engine (pistons and rods), gearbox and clutch which = a small fortune!


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## AdnanK (Jun 11, 2013)

rob2005 said:


> opcorn:
> Rods are being thrown left right and centre and the moment with at least 7 cars in the last few weeks that I know of through Batallion.
> 
> Anything over Stage 4.25 if you drive it hard will need forging other wise its only a matter of time before a Rod says hello.
> ...


Seen those posts too on B35, one of the more recent one was was a stage 4.25 who was capped at 620 lbft torque, rods exited engine. Ouch.


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## terry lloyd (Feb 12, 2014)

AdnanK said:


> Cooler temps and better flowing turbos etc would only result in more power being produced efficiently, but it's the 200+ lbft gain in torque over stock that bends these rods. I also understand driving style are a big factor too.
> 
> As mentioned before, I know of a MY14 Stage 5 car with all supporting mods bend rods, owner was lucky as it was going in for a forged engine.


I disagree - the bhp / torque gain is up to the mapper - i get the pressure bends the rods but metal bends easier the hotter it gets


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## Evo9lution (Aug 24, 2013)

grahamc said:


> or learn to drive better opcorn:
> 
> 
> 
> ...


The gearing in those cars is far better suited to high speeds as well ...

If you're forging for safety and still capping the torque to around stage 4.25 levels (+ maybe 10%), it may not stress the gearbox much if any more. I'm getting the shift upgrade from AC Speedtech at some point too and that gives an additional plate in the clutch pack anyway. Hopefully no synchros or gears will need any work at the same time ...


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## DocT (Dec 17, 2014)

grahamc said:


> or learn to drive better opcorn:
> 
> 
> 
> ...


No offence taken as I'm aware they're better drivers hence why I need more powers to catch them up on the straight after they've left me behind on the corners!

My plan is either 2 or 3 steps to get the end result from where I am now with each step costing 10-15k if possible (ideally less). So turbo's and manifold setup fitted + mapped, then forge engine and finally gearbox build. That's a lot more palpable and the incremental upgrades will keep me entertained than dropping 40k in one hit and waiting impatiently until I can justify spending that much in one go.


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## grahamc (Oct 1, 2006)

DocT said:


> No offence taken as I'm aware they're better drivers hence why I need more powers to catch them up on the straight after they've left me behind on the corners!


I dont know how well (or bad) you drive..... in the corners is brakes and weight, thats where you make the time up. If the weathers good R888R tyres 

How much quicker is a stage 5 car on acceleration out corners, etc? IE. own a track with the same driver?


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## AdnanK (Jun 11, 2013)

terry lloyd said:


> I disagree - the bhp / torque gain is up to the mapper - i get the pressure bends the rods but metal bends easier the hotter it gets


We've had stage 4's with stock turbos pushed to the extremes throwing rods and stage 5's with aftermarket turbos/intercoolers doing the same when torque goes north of 600 lbft with the stock engine, we've even had stock engines with stock power throwing rods.

If you want to run more than 600+ lbft torque with the stock engine and *track or drive the car hard *then either forge the engine or get a tuner warranty or it's only a matter of time.


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## DocT (Dec 17, 2014)

AdnanK said:


> We've had stage 4's with stock turbos pushed to the extremes throwing rods and stage 5's with aftermarket turbos/intercoolers doing the same when torque goes north of 600 lbft with the stock engine, we've even had stock engines with stock power throwing rods.
> 
> If you want to run more than 600+ lbft torque with the stock engine and *track or drive the car hard *then either forge the engine or get a tuner warranty or it's only a matter of time.


Is there any data on the failure rates of tuned GTR's?

I'm assuming there are 100's if not 1000+ tuned GTR. At what failure rate does it become statistically significant?


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## charles charlie (May 3, 2008)

Rod failures are simply cyclic fatigue of a high stress component that was never intended to be subjected to prolonged load beyond its design limits.

Reduce charge temps and lower boost by all means but if the load applied to the conrods (which in turn provides the torque that is applied to the crank) is excessive for long enough, they will bend. 

Metal is malleable , undergoes plastic deformation and has a limit to its flexural strength. That's when things go boom.


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## Evo9lution (Aug 24, 2013)

DocT said:


> Is there any data on the failure rates of tuned GTR's?
> 
> I'm assuming there are 100's if not 1000+ tuned GTR. At what failure rate does it become statistically significant?


Too many variables ...


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## terry lloyd (Feb 12, 2014)

Evo9lution said:


> Too many variables ...


True 

Plus how many are driving about with bent conrods - my guess is quite a few


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## DocT (Dec 17, 2014)

Evo9lution said:


> Too many variables ...


Of course but I'd just be interested to see raw data without extrapolating any conclusions.


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## borat52 (Jan 29, 2006)

terry lloyd said:


> True
> 
> Plus how many are driving about with bent conrods - my guess is quite a few


That's something I've often pondered (760bhp / 650lbft personally for 18 months now and circa 8k miles stock engine/box).

I tend to think that once the rod is slightly bent it can't hold on for very long before its toast as it's going to be undergoing stresses way out of it's design spec.

As a financial proposition, it really depends on how hard you can work your money. For me the money forging would be money not invested elsewhere and given I've now had 18 months without incident I'm pretty much at a point where that money has made a big enough return to pay for a new block if I encounter problems. I may not get any problems for the life of the car, it may go pop tomorrow - who knows.

One thing is for sure, if you are over stage 4 on a stock engine make sure you have enough cash set aside for a new block (£10k?).


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## rob2005 (Apr 26, 2015)

Thing is, the GTR is a superb beast of a car but your trying to keep up on with cars that are currently at the top of their game. The 488 and 675 are simply superb engineering artworks that will blow the GTR out of the water on spirited A roads. 

I honestly believe your quest for more BHP on OE internals and OE Gearbox would be a bad choice. I've seen well set up Stage 1 cars eat a new GT3 RS on a track and that's 580bhp but has a well set up car on KW coilovers, Cup's and Alcon BBK. 

Bet its fun driving with those beasts though!!


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## borat52 (Jan 29, 2006)

rob2005 said:


> The 488 and 675 are simply superb engineering artworks that will blow the GTR out of the water on spirited A roads.


I don't agree with that, if we're talking stock cars then the GTR is within a whisker of them on A roads. If anything it's going to lose out to them in a drag race due to bhp and weight.

I think realistically you would need to get the power weight close to them to make it fair, at which point I don't think they'd put any distance on a GTR.

In fact I think the GTR would be much easier to drive at close to the limit without fear of ending up in a tree due to to the 4WD.


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## DocT (Dec 17, 2014)

borat52 said:


> I don't agree with that, if we're talking stock cars then the GTR is within a whisker of them on A roads. If anything it's going to lose out to them in a drag race due to bhp and weight.
> 
> I think realistically you would need to get the power weight close to them to make it fair, at which point I don't think they'd put any distance on a GTR.
> 
> In fact I think the GTR would be much easier to drive at close to the limit without fear of ending up in a tree due to to the 4WD.


+1

AFAIK going fast isn't witchcraft, especially to overcome a delta on the straight it's power to weight ratio. The chap with the 675LT races it in a road car series and takes liberties on the road which I couldn't do if I had a £400k car.

I think forging the engine is prudent but at this point the "certainty" of sending a rod through the block with upgraded turbos and a safe tune is anecdotal. Even from my 4.25 a EFR turbo car seems to spool faster and have a bit more punch which would improve the driving experience IMO until I can justify funding a forged engine.


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## borat52 (Jan 29, 2006)

DocT said:


> +1
> 
> AFAIK going fast isn't witchcraft, especially to overcome a delta on the straight it's power to weight ratio. The chap with the 675LT races it in a road car series and takes liberties on the road which I couldn't do if I had a £400k car.
> 
> I think forging the engine is prudent but at this point the "certainty" of sending a rod through the block with upgraded turbos and a safe tune is anecdotal. Even from my 4.25 a EFR turbo car seems to spool faster and have a bit more punch which would improve the driving experience IMO until I can justify funding a forged engine.


I would personally be tempted to stick a pair of the Linney IHI900 turbos (paulmc used them on his DIY 800bhp). They're only £2500 + VAT and good for 800+ on 99 RON.

The litchfield EFR's are a work of art, but I don't see the extra £5k worth in them.

It also raises the option of sticking in the IHI900's and forging for the same price as the Litchfield EFR's.


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## Tin (Aug 15, 2010)

borat52 said:


> I would personally be tempted to stick a pair of the Linney IHI900 turbos (paulmc used them on his DIY 800bhp). They're only £2500 + VAT and good for 800+ on 99 RON.
> 
> The litchfield EFR's are a work of art, but I don't see the extra £5k worth in them.
> 
> It also raises the option of sticking in the IHI900's and forging for the same price as the Litchfield EFR's.


But would get the spool like the EFRs? Thats where the r&d has gone into with turbos & manifolds.


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## DocT (Dec 17, 2014)

Tin said:


> But would get the spool like the EFRs? Thats where the r&d has gone into with turbos & manifolds.


From what I understand for response there isn't anything better than the EFR's for this platform.

How much difference does the manifold make in the real world? I see Linney sells the EFR 6758 without the fancy manifolds for considerably less.


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## borat52 (Jan 29, 2006)

Sure the Litchfield EFR's are the holy grail of spool and power, but let's not beat around the bush here - your looking at £6k incl VAT on top of the Linney IHI's and £3800 on top of the Linney EFR's.

For a few hundred RPM difference in spool I don't think it stands up financially.

Money no object then of course you get the Litchfield EFR's, and I fully understand the R&D cost in them, you cannot allow that to muddy the actual result and how perceptible the difference is.

You could do the IHI's and forge for the cost of the Litchfield kit. That's a safe step and if you then decide a year down the line that you need that 200-500rpm spool difference you can swap the turbo's then with a safe engine in the mean time that you won't be afraid to crank right up.

A forged engine with the IHI's should push out 850bhp comfortably. 

850bhp is what you need to at parity with the Mclaren on power/weight - that's a very scary thought really.


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## gtr mart (Mar 29, 2004)

I had always wanted to do turbos, then the lump then the box. Each time releasing the turbos that bit more to feel the benefit of strengthening of the other components. As it seems to be panning out I am into the box at the moment which sucks as there will be no additional performance gain.

Doing turbos on their own, provided you pick sensible turbos - isn't neccesarily a bad idea on OEM rods. You can run 600/625lbft in the mid range but without the significant drop off in torque towards the red line which will liberate more power.

I agree with Terrys theory about the stock turbos running hot at stage 4 levels and as such a better cooler and less restrictive turbos could themselves aid reliability despite the extra top end power.

With all that said though, I too have seen the flurry of rod failures of late. Is it just the nature of the battalion facebook format and lack of user 'history' that promotes a nice open community - or genuinely more failures of late? I don't know, but it has certainly given me some food for thought and a renewed desire to forge my engine.


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## charles charlie (May 3, 2008)

We are seeing rod failures being reported more simply because of two factors. Many cars are 7 years old and have been running much power than stock for significant time now. Also there is more dissemination of information through social media.

As an example my 09 has 60k on it and has run stage 3 for 1 year and stage 4 for the last 5 years.

My clutch basket B went on Saturday (tbc today) and I'm not surprised. It'll get an upgraded clutch pack asap.

The risk of mechanical failure increases as a factor of load and time. We will see more failures and I do believe the number is vastly under reported for many reasons. The most likely is that folks don't want to publicise them as it may affect resale.


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## terry lloyd (Feb 12, 2014)

If mine breaks it will be all over the forum i dont care about the resale ( if its fixed i dont see a problem ) - my idea of a good forum is to learn about the cars good and bad 

What sort of hp/tq can the oem clutch hold ? also what are the uprated clutches like to live with


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## rob2005 (Apr 26, 2015)

I upgraded the baskets when recently having a shift upgrade done at AC Speedtech, they also fit a Linney clutches in the fix.

They are definitely harsher that OE due to the different friction materials I guess and at Low speed and rpm (when you wish the car would select 1st but it stays in 2nd) you can hear them chatter in the basket more. 

I'm going In tomorrow to have the shift points changed at lower rpm and for Andy to just refine the gearbox and engine Map for me.


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## charles charlie (May 3, 2008)

terry lloyd said:


> What sort of hp/tq can the oem clutch hold ? also what are the uprated clutches like to live with


The clutch friction plates seem okay up to 650-700 lbsft torque but age of them will determine how much slip will occur. That then means the clutch capacities need raising with a reduction in smoothness and driveability.

As my car has demonstrated (although a sample size of one means diddly) the next week point is usually clutch basket B (odd gears) which fractures the drive collar as its only lightly welded. Higher torque over long periods breaks that weld.

Aftermarket clutch packs are either just the friction plates and metal shims or the whole thing including baskets and Pistons.

If the tear down today shows a fractured basket collar (which I'm 99% sure it is) the I'm going full aftermarket baskets etc.

That'll be good for 1000bhp and 900 torques which will be okay for my planned engine build next year.

If I had the funds I do a full Albins gear set at the same time but thy simply isn't an option at the moment.

Neil Switzer and Tim Radley have used these aftermarket clutch switch excellent driveability and driver feedback.


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## charles charlie (May 3, 2008)

rob2005 said:


> I upgraded the baskets when recently having a shift upgrade done at AC Speedtech, they also fit a Linney clutches in the fix.
> 
> They are definitely harsher that OE due to the different friction materials I guess and at Low speed and rpm (when you wish the car would select 1st but it stays in 2nd) you can hear them chatter in the basket more.
> 
> I'm going In tomorrow to have the shift points changed at lower rpm and for Andy to just refine the gearbox and engine Map for me.


Aftermarket clutches require far more tinkering with the ECU and TCM maps to ensure they drive well. Torque tables need altering and having spoken with several experts in this area they have all said the same thing that it can take some time to dial in these upgrades to get the best settings. It isn't just about clutch touch point and capacities but the inter relationship between ECU and TCM maps.


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## gtr mart (Mar 29, 2004)

I broke basket B last year and upgraded to a billet Dodson upgrade. Despite 60k miles on the car the clutch plates showed little/no ware which I was pleased about.

I now have a syncro / selector sleeve 3rd/2nd issue so am weighing up the options for additional work whilst the box is out. I am thinking a Dodson/albins heavy duty first gear and shaft would be a sensible option for box strength but it boils down to cost.

I was a nats whisker away from agreeing an exchange with Jonny cocker (JCR) for his Albins built box, forged engine and his turbos but unfortunately it fell through. Those changes, whilst a big chunk of cash would have provided me with a great deal of reassurance about the potential for catastrophic failure.


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## charles charlie (May 3, 2008)

Well my trans was dropped today and my educated guess was spot on. Gold star for me!

Clutch basket B snapped at the output collar. That's the small piece bottom left. Xtreme Motorsport uprated 18 clutch pack on the way.



No drama. Simply a case of running bigger torque for many years. It could be welded and put back in but deffo worth the upgrade now. Can't wait to see how it drives!


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## vxrcymru (Sep 29, 2009)

charles charlie said:


> Well my trans was dropped today and my educated guess was spot on. Gold star for me!
> 
> Clutch basket B snapped at the output collar. That's the small piece bottom left. Xtreme Motorsport uprated 18 clutch pack on the way.
> 
> ...



Yep you were right.

And no other damage?

whats the bill for the fix?


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## charles charlie (May 3, 2008)

vxrcymru said:


> Yep you were right.
> 
> And no other damage?
> 
> whats the bill for the fix?


Thankfully a sheared clutch basket doesn't do any other damage other than the embarrassment of being pushed of Brunters last weekend!

I got the 18 plate complete clutch package direct from Xtreme so very competitive.


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## terry lloyd (Feb 12, 2014)

charles charlie said:


> Thankfully a sheared clutch basket doesn't do any other damage other than the embarrassment of being pushed of Brunters last weekend!
> 
> I got the 18 plate complete clutch package direct from Xtreme so very competitive.


Bit of a Extreme  fix - guessing you are going for more power later down the line ?


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## charles charlie (May 3, 2008)

Boom boom!!

Yep my plans were to do an engine build next year and cap the torque until such time I could afford to do the trans.

So I'll billet the clutch now and that way I'm safe and sound ready for next year. 

I spent all of last week doing some research into my options and using an OEM basket with strengthened welds was the cheap fix but now at least I'll be ready for next year.

Tim Radley (thanks Tim you're a star!) and Adam at Xtreme have both been incredibly helpful with some pointers as my engine and TCM maps will need adjustment of the mid shift torque tables in order to smooth out the shifts.

I'm hoping Ben Linney will be forthcoming when the cars ready with some updated maps. Xtreme supply a few tuners with their kits so hopefully it won't be too tricky to get right.


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## DocT (Dec 17, 2014)

What engine and turbo spec will you go with next year?


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## charles charlie (May 3, 2008)

Rods Pistons EFR 6758 turbos.

Supporting mods like fuel rail and pumps, SD tuning, intercooler etc

EFRs are my preferred option and I'd love to use Litchos but that's just too rich for me


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## vxrcymru (Sep 29, 2009)

charles charlie said:


> Boom boom!!
> 
> Yep my plans were to do an engine build next year and cap the torque until such time I could afford to do the trans.
> 
> ...



Well if you are going for more power it's a wise investment. Percentage wise how much more is the billet option compared to the cheap fix or simply replacing like for like with an OEM clutch basket?


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## charles charlie (May 3, 2008)

The stock baskets can be welded for more strength but the jury is out on whether this may actually weaken the basket long term where the weld may deform the basket itself.

Jacks transmissions in the US laser weld OEM baskets for not a lot and there are replacement billet units around the £600-£800 mark each and you need a pair. Obviously labour on top.

When you add in the cost of new friction plates (from around £1k up depending on spec and number) you're already at £2.5k or so. The Xtreme package also includes new Pistons with supposed longer lifespan which they say removes the 2nd to 3rd squawk that my car also suffered for years when cold.

So there are plenty of options should the need arise but I opted for a more complete solution and soon I'll see if it's been worth it.


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## Takamo (Oct 18, 2005)

My stage 5+ made a healthy 789.5 and 699.5lb of torque on standard internals and never missed a beat I'm a strong believer on that it's not power that kills the car it's 1.how the torque is dialled in and if it's mapped safely and 2. To not abuse the shite out of it. Power don't kill the car it's abuse that kills the car which is why you hear stories of stock cars going pop when they aren't driven correctly.


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## terry lloyd (Feb 12, 2014)

And 3 if them figures are Right


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## charles charlie (May 3, 2008)

Takamo said:


> My stage 5+ made a healthy 789.5 and 699.5lb of torque on standard internals and never missed a beat I'm a strong believer on that it's not power that kills the car it's 1.how the torque is dialled in and if it's mapped safely and 2. To not abuse the shite out of it. Power don't kill the car it's abuse that kills the car which is why you hear stories of stock cars going pop when they aren't driven correctly.


I think you're kinda missing the point though. Any car can have a failure. And at any time. That's why there are plenty of cars from all manufacturers that get work done under warranty.

With the GTR you can tune the engine to big HP without upgrading rods or upgrading the gearbox. How long it lasts will of course depend on the way it is driven, that is the level of load applied over what time frame and how often.

The greater the power, the greater the chance of failure. There is no magical line over which failures become 100%, or 25% etc. Just that the probability of failure increases as the power rises.

Misuse is a very vague term. The GTR was built to be a road car. Stick it on the track and it isnt being misused, just used differently and at higher loads for extended intervals.

Even road driving under heavy load stresses components and can cause premature failure depending upon the loading profile.

Your tune at that level will only remain healthy if the car has been built to withstand the extra load or is driven in such a way that the additional load that could be applied never is i.e. It's driven at lower RPM the majority of the time.

It not about misuse per se. It's about over stressing the components beyond what they're designed to take. The alloy of the roads for example doesn't know how erratic or otherwise the car is being driven. It just knows the load that's being applied.


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## AdnanK (Jun 11, 2013)

charles charlie said:


> which they say removes the 2nd to 3rd squawk that my car also suffered for years when cold.
> .


Most GTRs do this, my MY13 model has done this since 6k miles on the odo, I've now totally eliminated it with a clutch learn at 70c and slightly lifting off between gear changes when cold. Hasn't 'squawked' in months now.


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## charles charlie (May 3, 2008)

AdnanK said:


> Most GTRs do this, my MY13 model has done this since 6k miles on the odo, I've now totally illuminated it with a clutch learn at 70c and slightly lifting off between gear changes when cold.


Yes many cars have this quirk.

Having tried everything over 6 years to be rid of it and everything made no difference, we will see whether Xtreme's claims are true.

Only ever happened to me when cold and generally not in summer (so trans fluid temps lower than 15 deg c).

I'd actually never realised how clunky my trans was until I got a lift back from Brunters on JohnnyG's car.


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## Warnhammar (Aug 21, 2015)

What's the consensus on what the 2 to 3rd squawk noise is actually caused by? I have it on my car but only when cold and occasionally when warm under a medium amount of acceleration load. Always worried that it's causing damage. Especially after spending significant money on repairing my box already.


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## charles charlie (May 3, 2008)

Martin Donnon of Willall Racing in Oz posted this a while back

"Squawk" from Transmission on up shifts - Transmission & Drivetrain - GT-R Life

I have no other info to dispute or corroborate this description and he has been at the forefront of GR6 aftermarket development from the beginning.

It certainly seems a fairly sane theory however my logic can't explain why on my car it was only happens when the trans temp is below a certain level, is independent of the fluid used, and why only 2nd to 3rd shift and not any other gear.

What we can be sure of is that it isn't a problem nor does it lead to bigger issues.


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## Protegimus (Aug 31, 2011)

My car also had the squawk on 2nd to 3rd upshift when cold since I bought it, irrespective of transmission fluid (Nissan, Pentosin, Pentosin R or Motul) and not when ambient temperatures are mild or warm.

Last month it squawked during mild weather, day or so later the clutch seal failed leading to intermittent loss of shift to gears 2-4-6.
Willall Racing WR35PS GR6 Piston Seals were fitted along with replacement clutch plates to sort it. No further squawks.

Protegimus


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## charles charlie (May 3, 2008)

Protegimus said:


> My car also had the squawk on 2nd to 3rd upshift when cold since I bought it, irrespective of transmission fluid (Nissan, Pentosin, Pentosin R or Motul) and not when ambient temperatures are mild or warm.
> 
> Last month it squawked during mild weather, day or so later the clutch seal failed leading to intermittent loss of shift to gears 2-4-6.
> Willall Racing WR35PS GR6 Piston Seals were fitted along with replacement clutch plates to sort it. No further squawks.
> ...


Funny isnt it?

My aftermarket clutch baskets and frictions came with their own seals and it still squawks!


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## Trevgtr (Dec 24, 2012)

The chirp always seems to be 2nd to 3rd gear change when cold. I lift throttle pedal pressure on every gear change, it just gives a less harsh change, sounds nicer (less auto like) cures the chirp, and is ever so slightly kinder to the gear box long term IMO when just bimbling around. Obviously you don't ease pressure when nailing it hot.


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