I am experiencing an overboost problem, but only on my primary turbo. For example, the second that I mash the gas (especially in 3rd and up) the boost rises right up to 13-14psi very quickly, I then have a normal transition into the secondary, and when I am on both turbos I get 11psi rock solid like I should. I have my PFC set at .70bar for both turbos, I even turned the solenoid duty all the way down to 20% on the primary with no effect at all on the boost. The only mods on the car are the PFC, Blitz cat back, and Apex intake.. I had this problem even when I had the stock intake box and only the catback/PFC. What could be causing this? I did a test two weeks ago and removed the stock pill, my boost went to a normal 8-6-8 roughly so I put the pill back in.. now I get 14-8-11. What gives? Is it the pill?

Matt
93 SSM

 

Might be your wastegate cycle. 20%?? Try 70%-80%, that might help. At 20%, it would take a while for the PFC to learn and adjust for proper duty cycles. There's a few good threads on the PFC's boost settings. Try a search.

I don't know much about pills, however.

 

I am pretty positive from the PFC posts I have read that a lower duty cycle will open the wastegate sooner.. 5% is fully open and 95% is fully closed. The PFC cannot adjust lower than 20% it seems so I am stuck right now, if I up the duty cycle I am pretty sure it will spike up to fuel cut.. I'll double check on it though, I could easily be wrong here.

Matt
93 SSM

 

Ok.. after doing some much needed reading I think the problem is my wastegate solenoid. From what I understand the primary turbo is NOT controlled my the ECU under 4500RPM, it is controlled by this solenoid. Where is it located? I know there is only a short hose running down to both the wastegate and precontrol actuators. Someone knows the answer, cmon throw me a friggin bone here.. I have searched till my eyes bled.

Matt
93 SSM