Re: Boost fade
I did more tests the other day, here is what I've gathered:
boost controller was hooked up to turbo as pressure source, probably 12" of hose to turbo and 12" to wastegate.
I changed the pressure source to be the intake manifold, didn't help.
I lowered the boost one full turn on the controller. Nothing really changed except it made 17lbs and faded to 14. Weird.
I upped the boost two full turns, it made uncontrollable boost, instantly went to 25 lbs so I let off completely. Then I did a pull and controlled the throttle so it made 18 lbs, maybe 50% or 60% throttle, held solid to over 7k rpms.
The HZ on the AFC read something like 2400, I usually max out around 1700. This makes sense though (I think) because with the throttle body partially open, there would have been higher pressure in the pipes than the intake manifold, and the ssqv bov opened because I heard a high pitch airy sound past 5k rpms. So it was measuring more air than was getting to my engine, which is why it was so high probably.
Then I put it back to 1/8 turn over the original value, now it spikes to 19psi, then fades to 15 or 16.
So to me it seems like the boost is coming on too quickly and the boost controller can't keep it under control, takes 2k rpm to settle to where it should be. Could this be a wastegate problem?
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