Uncontrollable Boost

[95tsi]

I've always seemed to have a problem with my boost and setting it to a lower amont. I just installed a FP 17psi actuator on my T28 and now its boosting more than what pump gas can handle and producing knock. I've tried just about everything I can think of to get the manual boost controller to drop down the psi however, nothing seems to work. Even putting a spring on the wastegate to hold it up still creates 20+ psi. Right now I'm driving it with a vaccum line between the turbo and the wastegate canister and still pulling 23psi of boost.

Would porting the wastegate around the puck help? Or would you think it is somthing else? Any help would be greatly appreciated.

[SuperSleeper]

Run a vacuum line directly to the wastegate from the turbo, and see if that helps. If not, I'd say the actuator is faulty, or there's a hole in your vacuum line.

[JET]

The waste gate actuator probably needs to be adjusted. Turn the end onto the shaft more so it is putting less pressure on the wastegate puck. This will allow it to open more easily and should allow it to run lower boost.

Now if it is holding your set boost until higher rpm's, then goes up, that is boost creep and you need some porting done. Either QPR or myself could do that.

[95tsi]

Even with the vacuum line directly from the turbo to the wastegate canister it is still getting the 22psi of boost. I've had the stock actuator on just not hooked up to the flapper, then, wire the flapper wide open so the air will flow through and I still get upwards of 20+ psi of boost. It just spools really slowly up to around 12 then takes off. Although, it has always held steady with the manual boost controller which would lead me to think its not creeping.

[john]

Check for vaccum leaks. I have had holes in my vaccum lines which made boost uncontrolable. If none are found, I would try adjusting the wg actuator arm as JET described above.

[v8klla]

If you wired the WG open and still hit 20+ psi you definately have creep issues to take care of. Porting around the WG and a larger flapper will help out if that's the case.

Chris

[95tsi]

Thanks for the help. I guess its time to pull the turbo off again...

[JET]

Does the boost instantly go to 22 psi or take a bit to get up there? Like does it stay at low levels then go up as RPM's rise?

[95tsi]

It pretty much goes right up after it hits around 10. From there it just shoots up. When I was running it with the wastegate stuck open it would take a little bit for the boost to come on however, after it came on it just skyrocketed. Same idea with boost creep?