cannot boost over 15psi...HELP

19TTA89

I know 8sec Pete!!!
Joined
Feb 18, 2002
Went to the track last nite and noticed that the boost will not go past 15psi..no matter how much I adjust the wastegate..I have the gate adjusted all the way in and it still only hits 15..And seems to drop off to about 12 during a run..I have a R/A93 chip in it..And was running 100 octane with .7KR on scanmaster..What would be the cause of the limited boost and not being able to hold a steady 15.....Any Help greatly appreciated...Thnx Shawn.TTA #343..Oh yeah...fp set @45 line off...Did have a very lazy o2 sensor decided to die last nite...highest # i saw on o2's were 500...
 
Lots of possibilities here. Header leak? Crossover leak? WG actuator hooped? Do you run a spring from the WG pivot to the WG solenoid bracket? WG rod screwed in too far and not allowing the flapper to close? 'Y' connector on backwards? Check these out and get back to us.
HTH
Jim
 
Thanks for the reply guys.let me start by saying that I am new to these turbo cars so please bear with me...There is no cat on the car It has a test pipe with dump..Im not sure what the wg actuator being "hooped" would mean??I didnt notice any spring in that area at all...The rod is screwed in all the way..So I guess that could be a possibility...How Do I check That??There is in fact a header leak on the p/side..sounds like header...But only when cold..Seems to go away when warmed up...Could this be the problem..Maybe I just dont hear the leak under wot but it is still leaking warmed up..And would this cause my boost limitation..and falloff..Again Thnx guys...Shawn
 
If you have ANY exhaust leaks , start there. A sealed system only will give optimum performance. Hooped = screwed; filled with oil, old, not working correctly anymore. The spring is something you add, to help keep the WG closed until the desired boost is attained, then it opens. UNscrew the rod until the rod slips over the pin...then screw it in 4 turns [not half turns] and go for a blast...adj as required from there. I hope you have a scantool to view knock by this point...if not, relax this Holiday weekend and order one from Ramchargers, Ken Mosher or Direct Scan on Tuesday. If you can't afford this now, unscrew the WG rod until it slips over the pin and leave it alone until you can!
HTH
Jim
 
I had a slightly loose intercooler hose that allowed exactly 15psi. of boost and no more. Rock solid however.

Took me 3 months to find it, it was loose on the bottom under the clamp.

I'd double check ALL the hoses big and small associated with the turbo.
 
I will check all the hoses and make sure everything is good there...I have a scanmaster as far as kr#s I havent seen over 1 degree of knock yet.I will try loosening the wg back up and go with the 4 turn deal..see what happens..Thnx for the replies guys..Shawn
 
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