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Hi all,

Just wondering for people who have a r34 turbo on a rb20, what psi are you running?

Currently im running 14psi, but have heard 16psi is safe as its on a smaller engine the turbo isnt spinning as hard?

Would be great if i could turn up to 16psi, but just want to make sure before trying it.

They are still ceramic exhaust wheel so im assuming they couldnt be pushed too hard...

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im thinking it will spin the same when on full boost no matter what engine it is in.

i probably wouldnt push it

a larger displacement engine will produce more exhaust gasses.

Ive heard that because of this, the rb25 turbo on a rb20 can be dialed in to push more boost...

Although its all talk and wouldnt trust it unless someone can prove its safe.

i ran a R33 series 2 turbo on my R32 for nearly 2 years at 14psi daily driven without a problem. the turbo was still in good condition when i removed it. i know this isn't a R34 turbo but its close (both have ceramic turbine and nylon compressor).

These Nissan turbos are scary!

One more note on the comment about the power difference between 14 and 16psi..

I had my R33 Dyno'd on saturday for AFR purposes, and there was also an R32 with RB25 there.

For all intensive purposes, the modifications bolt on wise are the same, FMIC, Turbo back exhaust etc etc, only difference is my stuff is bling (Blitz, HKS etc) and his is China. Oh and he had a pod, and im using the Airbox.

Both running stock RB25 turbos.

(IGNORE the peak as its an NZ dyno and ours seem to read higher, but for the purpose of the topic its relavant as the two cars were run 1 after another)

His car made 216RWKW @ 14psi and a mild tune with a Link ECU.

Mine made 211RWKW @ 10psi with Stock ECU. My AFR's were off the chart :s Stock ECU fail!

5kw , Extra 4psi and a tune? Seems like the turbos working a shitload harder for sweet FA gain?

The only good thing about his was the tune made the car pull like a schoolboy in the midrange. It was incredible compared to mine. But top end from 4500ish RPM and over it was exactly the same.

Alot to read :) But something to consider. The turbos are small, and have to work exrtemely hard to make 12psi+ boost.

Edited by gotRICE?
4psi extra for 5rwkw extra yes..

but you're forgetting that you have 0.5L more capacity and 0.5 extra compression too.

My comparison was between two RB25s if you didnt notice.

And i would have thought also that an extra 5psi on a smaller engine, with less compression would make even less difference would it not?

being able to run higher pressures on a smaller engine makes sense if the ceramic wheels fail because of excessive rpm.

since the engine is smaller (smaller volume to fill) the turbocharger can rotate at lower rpm to produce a certain pressure.

heat will probably also be an issue. running lean even at a known 'safe' psi can end in high exhaust gas temperatures and premature turbo exhaust wheel failure.

I dont think theyre comparable at all.

Considering one has stock ECU and the other has a Link. Having a/m ECUs isnt an automatic +. Who knows what the tune was like...couldve been rubbish..

Considering the Tune was done by Andre @ Speedtech, who has many many sub 10 second drag cars under his belt, im sure the tune was just fine.

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