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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!!!

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My advice is to park it in my shed and give me the keys........................lol

When does you boost begin? If its 3,000 -3500 then thats normal. Your injectors could be beginning to lean out at top revs, 90% duty cycle is close to too much, little head room.

You don't need a hand controller, it can be tuned and driven without one.

take it to a reputable tuning shop and get them to check it out, wont cost much considering how much you have already spent buying it.

If you didnt like the lag why did you buy it, would have been plenty of other good powered options to buy that are more responsive.

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

yeah thats right, I even can't catch up a DC5-R when the boost not coming up. when the boost come up, the DC5 just like stoped.

My advice is to park it in my shed and give me the keys........................lol

When does you boost begin? If its 3,000 -3500 then thats normal. Your injectors could be beginning to lean out at top revs, 90% duty cycle is close to too much, little head room.

You don't need a hand controller, it can be tuned and driven without one.

yes, the boost start around 3000, full boost on 6000.

take it to a reputable tuning shop and get them to check it out, wont cost much considering how much you have already spent buying it.

If you didnt like the lag why did you buy it, would have been plenty of other good powered options to buy that are more responsive.

I like it, maybe I just not used to it.

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

thank you for reply, my last ride is a 135i and a evo9. the 135i like NA, no turbo lag at all. :)

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.

OK, the engine just finish rebuild. 13 is very lean I think, but my friend saw a lot black smoke when i push hard. and the 13 is for 410kw tune, I haven't see the 380kw dyno chat yet, but i guess they should be simily. maybe the 380kw's tune is richer.

OK, the engine just finish rebuild. 13 is very lean I think, but my friend saw a lot black smoke when i push hard. and the 13 is for 410kw tune, I haven't see the 380kw dyno chat yet, but i guess they should be simily. maybe the 380kw's tune is richer.

410rwkw on 600cc injectors.. :)

Dont flog it until a retune. Before you retune it though, get some bigger injectors.

Enjoy!

some hard push on street should be allright I think. but of cause no track work, I will definite take it to retune before any track work.

sounds fine to me, 13 is ok and 90% duty is ok

plonk it on a dyno for $50 insurance, but sounds fine

i wouldnt mess with the tune, unless something horribly is shown on the dyno check

Wrong.

:):blink:

Bye bye engine.

You can and will do some major damage unless it's fixed up.EG track day.

Either clean up the tune on the 600cc injectors with less boost etc.

Or upgrade your injectors and fuel system if it needs it.

Mine ran in the high 12's-low 13's a/f when I got my car, as it still had the jap tune. Drove it round for 6 months.

Ignition timing/detonation will do more damage than a leaner a/f.

Just my 2 cents (not worth much lol)

Cheers

:):blink:

Bye bye engine.

You can and will do some major damage unless it's fixed up.EG track day.

Either clean up the tune on the 600cc injectors with less boost etc.

Or upgrade your injectors and fuel system if it needs it.

Mine ran in the high 12's-low 13's a/f when I got my car, as it still had the jap tune. Drove it round for 6 months.

Ignition timing/detonation will do more damage than a leaner a/f.

Just my 2 cents (not worth much lol)

Cheers

thank you, i really confuse about the AFR, like my evo, its run 13-12 afr and 227awkw on SJ's dyno). but when I move to QLD, I did a dyno check, its run low 11 and high 10 afr and 195kws on Chiptorque dyno. same tune, different number.

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