I Just Bought A Gtr34. Need Some Advice . Thank You Very Much!

[PhilKenSebben]

Well if your last car was a Corolla sized BMW with a 3.5litre NA straight six under the hood, then yes you'll be disappointed with the lag in the GTR.

You'll get over it. Or you could give it to me. Your call.

[Nosure]

Well if your last car was a Corolla sized BMW with a 3.5litre NA straight six under the hood, then yes you'll be disappointed with the lag in the GTR.

You'll get over it. Or you could give it to me. Your call.

lol you are wrong, its L6 3.0 twin turbo. its a fun car, but of cause not fast as GTR haha.

[PhilKenSebben]

Really? So it's the same engine as the 335ci? Rock on! Dude bugger the GTR its laggy and crap and about to explode. Give it to me and go back to the 135.

Edited March 22, 2009 by purpleisafruit

[Brandon]

NICE! enjoy your new ride.

[PM-R33]

Really? So it's the same engine as the 335ci? Rock on! Dude bugger the GTR its laggy and crap and about to explode. Give it to me and go back to the 135.

Yep sure is, the 135i is a great car. With an exhaust upgrade and a slight ECU remap, 250rwkw is a piece of piss to achieve out of them. A M3 killer for half the money.

[Brockas]

13 is too lean at the top end.. if it is actually that lean at 7-8000rpm you will kill your engine very quickly. get it on a dyno asap.

What exactly do you base this on? The AFR's may be in the 13's, but what is the ignition advance? This is what I would be far more concerned about.

There seem to be plenty of keyboard tuners around who are obsessed with AFR's.

Does it knock? Does the engine warning light flash? If not, the tune is probably safe enough. Get it checked anyway by someone you trust. Don't rely on anything said to you on an internet forum about your tune, as most people dont have a clue.

[Strik3r]

just because its not pinging doesn't mean that it wont melt a piston. I doubt you will find many tuners saying a 13:1 AFR is A-OK at 7000-8000 rpm on a car making 500awhp.

Only my 2c anyway. Do what you will.

[STATUS]

Hi I just bought a GTR34 vspec, and want to make sure everything is safe.

now the car currenly run 380kw on wheel 21psi, boost by t517z*2. the turbo lag is really big, full boost around 6000rpm. and the AFR is look a bit lean, 4000rpm about 12AFR 7000-8000 around 13AFR.(I don't know about GTR, but my evo is allways under 12) the owner told me is very safe, no need retune. and the injector is nismo 600cc. if i don't want tune up the power do i need some bigger injector???the highest injector duty is about 90%+. but i'm sure its not 100%

the car only done 2500kms after engine rebuild. so i may need change to full syn engine oil when its up to 3000kms.

and the car doesn't have power fc hand controller. do i need one???

can you guys give me some suggestion, what should I do next??? retune it?? bigger injector?? etc....

the car running really good, its not like a 10 years car. and many nice mods. easy daily drive. I just don't like the big turbo lag.

please help thanks guys!!!

It sounds like someone has fitted the 10cm versions which are designed for more mods and higher boost pressures.

If it was mine i would swap to the 8cm rear, it will give you much better response, the housings are available separatley. My old 32 made 312 on 16-17 odd psi and similar power to yours at 22psi. Full boost was FAR lower than yours also, very similar to gt2530's.

[NickR33]

I was just about to ask what rear housings... I get full boost well before 6000rpm, but it only makes 360rwkw @20psi (8cm rear housings)... definitely sounds like you have the 10cms... get some bigger injectors

[Nosure]

What exactly do you base this on? The AFR's may be in the 13's, but what is the ignition advance? This is what I would be far more concerned about.

There seem to be plenty of keyboard tuners around who are obsessed with AFR's.

Does it knock? Does the engine warning light flash? If not, the tune is probably safe enough. Get it checked anyway by someone you trust. Don't rely on anything said to you on an internet forum about your tune, as most people dont have a clue.

I can't hear any knock, and no engine light at all. car drive great.

thank you for advice!

[Nosure]

I was just about to ask what rear housings... I get full boost well before 6000rpm, but it only makes 360rwkw @20psi (8cm rear housings)... definitely sounds like you have the 10cms... get some bigger injectors

thank you, I already talk to tuner, he said sard 700cc should be enough for me. and the turbo lag is normal. anyway I will get a retune next week.

thank you!

[Nosure]

Yep sure is, the 135i is a great car. With an exhaust upgrade and a slight ECU remap, 250rwkw is a piece of piss to achieve out of them. A M3 killer for half the money.

yeah, a 135i can make 400hp with full exhaust and higher boost.

the 135i I got, made 222kw and 540nm torque on rear wheels with only a piggyback.

but the GTR is best haha!!

[Nosure]

just because its not pinging doesn't mean that it wont melt a piston. I doubt you will find many tuners saying a 13:1 AFR is A-OK at 7000-8000 rpm on a car making 500awhp.

Only my 2c anyway. Do what you will.

thank you.

the owner told me the car is tuned by the guy who tuned fastest GTR in SA.

and the car could make 420kw at limit. but he go down to 380kw for engine's life.

[Nosure]

There seem to be plenty of keyboard tuners around who are obsessed with AFR's.

Don't rely on anything said to you on an internet forum about your tune, as most people dont have a clue.

yeah thats right. every car forum is same.

[cactus]

yeah thats right. every car forum is same.

lol, why bother asking for help then...

[GTRNUR]

thank you.

the owner told me the car is tuned by the guy who tuned fastest GTR in SA.

and the car could make 420kw at limit. but he go down to 380kw for engine's life.

I'd be inclined to say that 13:1 would be moderately safe if you were also running water injection on the car, and the car has also been tuned with an exhaust gas temp sensor in the system. Otherwise id be suggesting 11.8:1 in the 7000 RPM range when at full load/boost.

When the ignition settings were too tame ive seen the AFR's go torwards the rich side of the scale, not the lean side, due to un-burnt fuel making the AFR appear more rich. Though lean combined with not enough ignition advance REALLY gets the exhaust temps to rise, as your putting more un-burnt fuel out the exhaust (less burning in the combustion chamber). A doey "soft" ignition tune can cause higher EGT's than the correct ignition advance.

[VB-]

X2 for A:F ratio isnt as bad as everyone is making it out to be.

to the guy on the previous page, your motor died because your running lower quality fuel over here (lower oct. rating, meaning your ignition timing was too far advanced) NOT because it was running at 13:1. even with a richer mixture, odds are the same thing would have happened

anyone ever read up on Nissan's Le Mans car? cant remember which one it was specifically, but they ran a lambda of 1 for the entire race. (not going to say 14.7 to one coz i dont know what fuel it was run on specifically)

nizpro have also done tests, running an XR6T motor from memory flat out on a dyno, at 14.7:1 also. detonation is cause more by ignition timing that A:F ratio from what i've found

[GTRNUR]

Yeah thats it... The pistons tend to melt after the detonation blows the ring lands off them, allowing combustion gasses to blow by the rings at high pressure and melt parts of the pistons...

Still get it checked though.

I wonder if the nispro cars were using ceramic coatings on the pistons to get away with that. 14.7 is the AFR that produces the least hydrocarbons while not making too much NO2. Ive tuned to 17:1 for light load economy, but thats an entirely diferent story.

Edited March 23, 2009 by GTRNUR

[MrStabby]

I have no first hand knowledge, but from what i've observed/read/heard;

- Oz tuners tend to like 12:1, jap tuners more like 10.8:1

- To a limited degree you can trade off AFR and timing (jap tuners tend to use more timing as well as more fuel)

- A tune trades off risk vs power. I am risk averse, so i'm running 11.5 (also to keep EGTs down with my old ceramic turbine wheels...). You should tell your tuner if you want extra safety or max power.

- But that said, I also reckon you need bigger injectors and a richer tune

[VB-]

yeah but you start to hit problems going too rich aswell. seems alot of people think if you just go richer it makes it safer... not true.

GTRNUR, cant be sure on the nizpro car, was too long ago. cant remember anything about EGT's either which is obviously the main concern running a tune like that... might have to try and dig it up