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Boost drop at higher revs

Pekatu

By Pekatu,
in General Automotive Discussion

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R31 POWER Mentor

R31 POWER

Posted
Posted

Yeah mine does the same,I have a R32 RB20det in my R31 and before it was intercooled it did the samething as intercooled.

12psi and then drop to 10psi @5000rpm.

Now it has 3inch dump/zorst/pod and does the same still,HKS GT2530 and will fix that:uh-huh:

red17 Experienced

red17

Posted
Posted

Mine does the same thing, its normal. Not necessarily caused by the factory wastegate but probably more that you are reaching the peak of the stock turbochargers efficency. Gradually as shaft rpm increases air starts to spill off the impeller rather than going through it, dropping efficency.

An EBC wont fix this. Ive got one and it sure as hell dont fix it.

Red17

Kinks Grand Master

Kinks

Posted
Posted

My RB20 runs 1 bar in the midrange but drops back to around 10psi up top, I would guess that the turbo and manifold pose a restriction which limits boost. EBC might make things better, the bleed valve I am using is renowned for spiking. But seems to be more a feature of revs since in a high gear it will hold around 14 pound in the midrange.

Might be time to go an RB25 turbo :)

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