Safe boost level for stock 1JZ VVTI

[shweatypox]

What is stock and what is safe to turn up to?

[99jzx100]

ive only got mine sitting on 10 pound and still pulls pretty hard

[Alex]

haha yeah ^ but yours is running a Rasty high flow

[Alex]

What is stock and what is safe to turn up to?

chuck a boost guage on and see, can vary a wee bit,
but iirc its around 8-10 psi stock...

[twojayzeejza]

all depends on the a/f ratio just chuck it on a dyno and have it checked, know one will tell you whats safe boost level

[crux]

The 1jz VVTi has no factory boost control at all, which I found a bit weird.

With no modifications, it should be running around 7-8psi.
With intercooler, exhaust + dump pipe, intake mods it should see anywhere from 10-13psi depending.

I run just over 14.5psi (1bar) with a boost tap.

Factory turbo doesnt really hold 14psi that well in the higher rev's but it's all good.

Alot of people run even more boost, around 16psi. I don't think the engine itself is the problem as the ECU overfuels quite a bit. The bigger problem is the factory ceramic turbo crapping itself!

[shweatypox]

sounds like 12psi will be a good setting until I upgrade the turbo then.

[dom]

My chaser is running 0.7bar (10-11psi) with pod/fmic/3.5" exhaust. From what i've heard its safe to go up to 15psi with factory ceramic turbo, but in saying this I have personally annihilated 2 factory ceramic exhaust wheels on 10psi. I've got a steel-wheeled factory turbo now which will hopefully be capable of giving me a safe and reliable 15psi.

[SimonMkII]

I believe the factory ECU will cut power over 15psi. At least mine always did when I had my big turbo.

[VR25]

The Verossa is running 16psi any day and everyday . Yeah , I do get fuel cut but hey , getting there is all the fun !