i have a k-29#8 kkk on my 86 951, i have k-27 chips for it a stage4 mass kit, arc2, arm1, free flow intake/exhaust, adj.wastegate and boost controller set to 20 psi max, now my question is im using a 3bar fuel pressure regulator and new stock injectors with a high flow bosch fuel pump, i know i can increase the power with more fuel but how much do i need at 20-21 psi of boost? what do i set my new adjustable regulator at in fuel psi at idle so it increases properly for my 20 psi setup? do i need bigger injectors too? i think i need one or both because i have to turn my arc2 to real rich so i dont go lean under full boost, my settings are low:10:30 med: 2:00 high:3:00 accel:2:30 i cant go lower on the med high or accel or as the k29 goes into full boost the arm 1 goes to full red meaning im going lean, as the settings arre now im getting a green to blue reading so im ok but i think i need my fuel pressure raised up alot, can someone who is a fuel expert tell me what fuel pressure i need to set at my adj. regulator and if i can get away without big injectors or what else thanks in advance

 

I have a fairly similar set up on my car, but without the larger vol FP and upgraded turbo (I have the MAF, Straight exh, etc). I have found on mine that 3.0-ish bar is the right pressure at idle......more fp shows I run a bit richer (bgo) on my a/f, but the car is not a smooth above 3.0. given your higher boost level, I would think you MAY need more than 3.0

YOu may want to get an injector cycle monitor to see what % they are cycled on. I have been told >85% and you need bigger injectors.

You may want to call the guys at Lindsey Racing, ask about the larger injectors they sell, and see what they recommend as far as inj size and FP. They run a 951 with a setup that sounds similar to yours.