to much boost
12-08-09, 12:15 AM
#1
to much boost
I have a 1988 t2 with jdm motor fresh , block off plates ,intake , stock turbo ported wastegate, 2 and 1/2 inch pipping with stock cat .. it was hallowed out but thought might help if it was stock.. well whats happening is im just shooting upto 15 lbs by 4800 rpms and it if i didnt shift probably even higher . cant figure out why if anyone has any thought shed some light thnxs
12-08-09, 09:04 AM
#2
Engine, Not Motor
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Are you sure the wastegate is ported? Is the actuator connected to the swing valve? Is there a vacuum line from the actuator to the nipple on the compressor?
Boost control issues on S4 are common because the wastegate is very small and only leads to a single runner. You'll need to port it larger or restrict the intake/exhaust.
Boost control issues on S4 are common because the wastegate is very small and only leads to a single runner. You'll need to port it larger or restrict the intake/exhaust.
12-08-09, 02:01 PM
#4
I hate to say it, but it's probably just not ported large enough. The S4 wastegate port is only 13mm stock, so you'd be at roughly 26mm now. That's still pretty small. The stock S5 wastegate has more area than that, and can still creep with modified exhaust systems.
12-14-09, 09:23 AM
#6
Engine, Not Motor
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The wastegate is so small that you would still boost, and probably overboost. I tuned a car with a ported S4 wastegate wide open and it would still hit 14 PSI before 5000 RPM.
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