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Boost creep

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Hello,

I’m tuning a Gt86 with a bolt on turbo using brzedit. I want to limit the boost with the Waste gate at 0.8bar, however the boost creeps to 1.2bar at 7000rpm.

Is there Any ways to control the boost with stock ecu? Any one has experience could share some guidelines?

Thank you very much!

What is the wastegate spring rated at?

Is it internal or external wastegate?

If it's internal gate and creeping high beyond the spring rating you could only lower boost if ignition timing is overly retarded at high rpm and you correct it, reducing exhaust energy, in terms of ecu control.

People often have to port internal wastegates to improve high rpm boost control, I would look down that path. You can intentionally restrict the exhaust to reduce turbine efficency but that is less than ideal.

Thanks for the reply!

I do not know the spring rating, i may have to ask the manufacturer who made the turbo kit.

however, it says on the manual that the waste gate is preset to 80-90kpa.

since I’m using pump fuel, the engine is knock limited. Advancing ignition can only get me so far.

Could i control the boost using DWB throttle body or exhaust cam timing?

DBW control will depend on ecu software capability, retarding exhaust cam would likely soften it a bit.

I would definitely have a go at the turbine housing with a carbide or emery bit to improve flow into and through the wastegate.