[dirtbag]

The wastegate is vacuum actuated. It requires vacuum (cam driven vacuum pump) in order for it to remain closed to provide boost. The brake booster is also driven from this same pump.

Do the brakes feel different? If so, there could be a leak somewhere in the vacuum system. I wouldn't rule out a small rip in the wastegate diaphragm. That one is easy to test. With the engine off, disconnect the hose from the wastegate and attach a mighty vac to the wastegate. Pulling vacuum should close the wastegate (you'll see the arm/rod move).


If there's no leaks in the system, the solenoid that controls how much vacuum the wastegate sees could be bad. It's somewhere on the back of the engine if I recall.

There are other things that could command the wastegate to remain open. Overboost or brake system faults (like resting your foot on the brake and accelerator at the same time), but those almost always trigger a code, and reset after every engine restart.


If she keeps her foot down on the throttle in a high gear for long enough, an underboost style fault should trip. I think it takes something like 10-15 seconds though.

Anyway just some ideas.



Yeah, it's really slow without boost. All 70whp worth. I have a button that disables my wastegate intentionally to prevent the car from going into boost. I mostly use it to prevent from going into boost before operating temps are reached.