overboost problem

[1987ttype]

I recently replaced my TA60 with a new GT6152. I had to change one of the wastegate solenoid hoses because of the different location of the compressor pressure outlet. I hooked up the "Y" fitting correctly with the restriction towards the compressor outlet. i'm still getting 25+ psi of boost (i didn't stay on it to see how high it would go). It spools somewhat slow (slower than the TA60) but that is most likely due to the fact that my actuator rod is set as loose as possible. please help, i'm getting over 25 psi at not even WOT.

 

[scottyb]

I'd pull the boost control lines off again and verify they are good, and nothing is blocking the oriface.

 

[1987ttype]

just pulled off all the lines, everything looks good nothing blocking the restrictor or any of the lines. any other ideas?

 

[turbo2nr]

Take off the actuator arm, is it free moving when hot? Do you by chance have an atr down pipe? Is wastegate solonoid making noise with engine off, ign. on, and wot? Unplug it if it is, and go from there.

Scott

 

[1987ttype]

actuator arm is moving. i loostened the rod alittle more and i built up the courage to stay in it. i'm getting a steady 26psi now (no knock thanks to alky) but spool up is fairly slow (still probably due to the actuaor opening so early). I don't notice any noise from the solenoid but I will try and disconnect the solenoid tomorrow, hope that is the problem. Thanks for the advice.

 

[wiked87gn]

try porting the hole on the turbo to match the puck of the wastegate, very common problem, the car will overboost due to the hole being smaller than the puck thus not releasing boost fast enough, just my 02's.

 

[turbo2nr]

I've heard and seen a little boost creep, but 26psi!??? I just thought of something! Take off line to actuator, blow in it. I bet you may have a ruptured diaphram in it. No air should pass through.

 

[1987ttype]

just an update. the actuator diaphram is ok. i ported out the wastegate hole per the advice on this thread and Mike at Fullthrottlespeed. ported it out to less than 1/8" for where the puck seals. boost is down to ~21-22 at lowest setting with the wastegate rod. I did a search on the P/N for HD acutators and it seems like i have a HD one, but that should still go down to ~18psi. either way 21 psi is managable without the alcohol, thanks for the advice and thanks mike at FullThrottleSpeed.com.