After Change A Bigger Compressor Wheel

[reno chin GTT]

hi all members!

i my facing a new problem, after i change a new turbo (actaully a same type of stock turbo replace a bigger compressor and turbine wheel) the car rpm drop to 300rpm or nearly stall, when i stay on 2500rpm up to 4000 rpm , but if i full throttle its fine, this all happen just after change the turbo, check already with MAF / fuel pressure regulator / spark plug/ and even install emanage ultimate, BOV circulation . do you think the turbo is not suitable with my inlet manifold? compressor stall ?

heard people said is boost cut , but before 0.8 bar also no cut why this time 0.5 bar already cut, they said bcoz bigger compressor wheel, do you think is true?

skyline r34 GTT Auto Trans

emanage ultimate

stock injector

HKS pod

ext wastegate 0.7bar

after market dumb pipe

stock AFM

[Room42]

Vacuum leak?

[R31Nismoid]

turbo install is the issue, keep checking things. I say VAC line too.

But have you retuned since the install?

[reno chin GTT]

already check Vacuum leak, fully secure and tight, even change new hose. diagnose no fault code, what if exhaust manifold leak?

after problem occur i install emanage hope can solve but its the same. but my final decision will put back the ori stock turbo, if everything ok, then is the turbo.

[R31Nismoid]

a drop in RPM @ idle has nothing to do with the turbo... It's not doing anything!

[reno chin GTT]

i change back to the stock turbo, and the problem solve, the stock turbo is 0.63 AR and new turbo is 0.48 AR , stock is single blade ,new turbo is double blade.

which i think it cause the problem ?

[Rolls]

at idle it wont make any difference, unless the new turbo has a leak in the gasket?

[GTScotT]

Is your new turbo seized or does it spin easy?

I once had this problem when the turbo could not spin easy.

Also, make sure your compressor housing is not leaking vacuum. The housing has an o-ring where it meets the backing plate.

GL, makasi.