I just installed a new (tuned) Power FC from SR Motorsports in the hopes of clearing up a huge boost spike occuring at the 4500 RPM turbo transition point. The car is running the stock sequentials and stage 3 mods (it was running a Pettit ECU). The power FC is supposed to be tuned for 12 PSI. While it seems to have reduced the likelihood of the boost spike, I am still seeing peak boost pressures of 16+ psi on my SPA digital gauge. Does anyone have any idea why the Power FC might not be properly adjusting the boost? Anything I should be looking for?

Thanks,

Jim

 

The PFC is never tuned for one psi like you so called 12psi. Even the Pettit is not tuned for one PSI. They do have a maximum PSI that they may be tuned to. The PFC can handle any PSI if all is set up properly including a 3 BAR map sensor. Read your manual and you will see. Study and you will understand.

The spike problem is caused by the slow responce of the WG solenoid and WG to dump pressure when it builds up fast. A ported WG plus a good after market boost controller can fix that problem. Get a Blitz Dual SBC R.

 

hey chuck, he said his spike was at 4500, wouldnt that be the Pre-control gate not opening (venting to secondary)...not the wastegate like you mentioned?

 

The pre-control diverts exhaust to the #2 turbo and if is late coming on will normally cause boost to drop during transition. This is caused by too little spool up of #2.

If it opens too soon, #2 can overspool causing too much boost or spike during transistion. Best to place a valve in the precontrol line to adjust the timing of the gate opening up. I use to have two valves when I had the Home Depot valve boost controller. Adjusted the WG valve for overall max boost, then played with the PC
valve for smoothest transistion.

Best way to adjust this is a full blown non-seq conversion. HeHe!!

 

pfc arent too good at controlling boost and boost spikes. need to get yourself another boost controller.

 

oops, what i ment was that the PC valve was venting too much to the secodary, so that when it came on at transition it was over spooled, causing his spike at transition.