Help/advice Please - R34 Stock Turbo Boost Levels

[itsme]

Hi All,

I have an R34 GTT manual sedan with specs as follows;

Stock turbo and internals

Splitfire coilpacks

Iridium spark plugs

Exedy HD clutch and lightened flywheel

Walbro 550lhp in-tank fuel pump

Blitz turn-flow cooler

Cooling pro alloy radiator

BC racing coilovers

R32 76.5deg thermostat

Exhaust from the turbo back with hi-flow cat

Profec B Spec II

Basically I wanted to do all the supporting mods so that in a weeks time when i get the PFC + handcontroller installed and tuned it should all be fairly safe and it's about as far as my budget could stretch before going the next step of a new turbo and bigger injectors etc.

Basically I was wondering if anybody else had similar mods running a stock turbo and how they've found it, what sort of boost you're running and any advice on the best high and low boost settings. I was thinking low of 7 and high of 12 but I've spoken to a few people who think low 10 and high 14 would be acceptable. Any help would be greatly appreciated in the way of real-world experience, kw/hp numbers achieved and any pros and cons. I realise the 34 turbo is ceramic and can shatter at high speeds so I want to be relatively cautious until I can afford a new turbo down the track.

cheers,

Steve

[wolverine]

Go with your instinct.

12psi high boost is "relatively" safe and you will get about 200rwkw +/-10kw

I've spoken to a few people who think low 10 and high 14 would be acceptable

This has been covered to death. It is possible it might last 2 years it might last 1 day but commonsense should tell you that the lowest level of boost you can get away with and get still get reasonable performance is the best place to set the peak boost.

A good tuner should know what is reasonable.

[itsme]

Cheers Wolverine appreciate the assistance dude.

The tuner is really good and has a good reputation so maybe it would be best to address these queries with him direct, he's just a very busy man and don't wanna bug him too much with being a noob.

On the basis that it could last 1 day or 2 years I think you're right in saying to go with my instinct - 2 years would be cool coz I'm sure I'd have cash for a new turbo by then but if it lasts any shorter than that I could be carless for a while.

[rgr34]

i have ran 11.5psi for yrs in my r34 sedan not tuned at all i have is a full exhaust and pod /cai, spark plugs regapped slightly.. never had a issue but i dont drive it hard often. you however have all the supporting mods id say low 10 or so... and high 13 would be acceptable on the stock turbo....

Edited September 7, 2010 by rgr34

[R31Nismoid]

Just tell the tuner 12psi max, thats it.

It's your car, its your call regardless.

For long turbo life, 12psi is the limit realistically.

[Harey]

My tune didnt even want to run 11psi. He said 10psi max, his opinion was its not worth the risk for the small gain.

[Randon_I_Am]

Mine was tuned at 11psi and made 215rwkw. Very similar mods too.

[itsme]

Just tell the tuner 12psi max, thats it.

It's your car, its your call regardless.

For long turbo life, 12psi is the limit realistically.

Cheers mate, 12psi max seemed to be the going consensus from all the info I've read so I think I will just ask to make that the max and in all your wisdom I wouldn't second guess it now you've said it also.

thanks Nismoid.

[itsme]

Mine was tuned at 11psi and made 215rwkw. Very similar mods too.

Cheers mate that's awesome, I've not been able to find any comparison as most people at this stage have upgraded the turbo.

This is going to be a huge noob question and I expect flaming (please be gentle). From everything I've read the R34GTT is 206kw out of the factory (not sure how true this is as all data points to the r32 gtr being the same so I was thinking this may of been a lie due to power restrictions in Japan =/ )

I'm gathering the 206kw is measured at the flywheel or something because I'd be shattered if all my mods and money and time added 9kw =/

If i were to go on the basis that my car stock is 206kw at the flywheel and I may be hoping to expect 215kw at the rear wheels is there any easy way of determining (even very roughly) how much of a power increase I've gone to from stock. (ie does anybody know the stock rwkw for an r34gtt)

End of the day I don't want to be hektik and get a tune just for numbers on a sheet, i want real world response and really love and enjoy my car i'm just questioning this for curiosities sake and with the hope of learning/understanding a little more.

[Mattw_83]

Cheers mate that's awesome, I've not been able to find any comparison as most people at this stage have upgraded the turbo.

This is going to be a huge noob question and I expect flaming (please be gentle). From everything I've read the R34GTT is 206kw out of the factory (not sure how true this is as all data points to the r32 gtr being the same so I was thinking this may of been a lie due to power restrictions in Japan =/ )

I'm gathering the 206kw is measured at the flywheel or something because I'd be shattered if all my mods and money and time added 9kw =/

If i were to go on the basis that my car stock is 206kw at the flywheel and I may be hoping to expect 215kw at the rear wheels is there any easy way of determining (even very roughly) how much of a power increase I've gone to from stock. (ie does anybody know the stock rwkw for an r34gtt)

End of the day I don't want to be hektik and get a tune just for numbers on a sheet, i want real world response and really love and enjoy my car i'm just questioning this for curiosities sake and with the hope of learning/understanding a little more.

When my r33 Gts25t S2 was stock it made 157RWKw.

[Trozzle]

Factory power ratings are always at the flywheel, never at the wheels. R33 GTS-T was 187kw at the fly, and I believe roughly 154kw at the rear wheels. If the R34 GT-T was actually 206kw at the fly, then I would assume somewhere in the vicinity of 170-177kw at the rear wheels.

Also, I'm not sure on the 206kw deal between the R32 GT-R and R34 GT-T, but it may be concerning the "gentleman's agreement" between the Japs, in which they didn't advertise their cars as having more than that

[Harey]

My 34 GT-T with catback exhaust and pod filter made ~165rwkw. So I would expect a full stocker to make ~150rwkw.

Have a look here for the modification guide:

http://www.skylinesaustralia.com/forums/Ni...p;mode=threaded

[wolverine]

Most stock GTS-t and GT-t skylines have shown around 60kw in drivetrain losses.

So a stock GTS-t often comes in around 130rwkw and a GT-t around 145rwkw. Some higher some lower so take it with a grain of salt as a dyno is a tuning tool not an absolute truth meter.

[Rolls]

Is there really that much difference between the neo and the r33 rb25?