? about external wastegates and ITS boost controller

[NoSlix]

To start with, this is not on a Turbo 6. But you guys know more about turbos than most other sites. It's my T76 powered, liquid to air cooled, 310ci Mustang. It's got an Innovative Turbo dual ball bearing R trim 76mm. I'm also using Innovative's ProGate and MSBC boost controller. ITS tells me the wastegate should have a 7-15 psi adjustment range. Since I got this car running, it's always had a boost control problem. You could sit on the transbrake for 5 seconds before seeing 6psi. We tried everything to do with the FAST tuneup, increased the size of the wastegate feed tube, changed converters, etc. Once you let go of the brake, it would build boost slowly until it hit 15psi at 6200rpm(about the 330' mark) and then hold there. Once it hit 15psi, it was "on" from there on out and the car will run 9.70 at 146mph on drag radials like that. Turning the wastegate tension spring doesn't improve spoolup or increase the peak boost and neither does changing the MSBC. I've tested the MSBC with my own regulator to verify that the correct solenoids are cycling at the correct time. Today, we realized that you can see the wastegate starting to let out the exhaust gasses as soon as the boost starts to build. We unhooked the pressure side of the wastegate, leaving only the control side hooked up with the MSBC in line. WHAM! 18psi on the brake almost instantly before I let out. So we pulled the gate, hooked a small regulator, compressor, and pressure gauge to it and verified that the valve is opening between 3 and 5psi and that's with no exhaust pressure pushing against the valve. Is this as simple to fix as getting the correct spring from ITS? Or is their some dynamic to this that we're not thinking about? Thanks for any help you can give me. We've been jacking with this thing, not realizing it was possibly the wastegate, for two months. ITS has been telling me it's not the wastegate and MSBC, but it seems to me like they are the culprit.

Regards,
Shane Hill
NMRA DR10046
9.70 at 146mph on drag radials

 

[NoSlix]

Just to let you guys know, because this might effect some of you sometime.........the problem was the Innovative Turbo wastegate. I swapped on a Turbonetics Racegate and the problem magically went away. As soon as I stood it on the brake and floored it, the boost gauge went past 18psi. I've talked to two other guys who have had very similar problems with their ITS gates, with the same results after switching to Racegates.

Regards,
Shane Hill

 

[NoSlix]

Have talked with Rick Head at Innovative and Joe Thomas, who manufactures the MSBC for Innovative. I'm to send the wastegate back for testing and he's sending me a brand new one. The interesting thing is that we tested my gate's spring, as well as two other springs from my buddies ITS gates on a digitial spring tester/logger. Mine had identical rates all the way to coil bind, yet my gate opens a full 3-4 psi earlier than the others.

Shane Hill