I have a 1991 Formula 350 with stock injectors with the following mods. The SLP runners, SLP cold air box, Edelbrock intake (not modified), air foil, Edelbrock tubular headers, gutted dual cats and SLP prom chip with a BORLA 3" exhaust. I also have taken out the bumps in the opening of the intake plenum right behind the stock throttle body. I have played around with the adjustable pressure reading on the dial (it goes to 60 p.s.i.) and seemed to have found that 50 p.s.i. at IDLE seems to work best, but what is the best way to check the actual pressure and what do you have to disconnect. I see that 43.5 works best or just a bit more with my mods. I have an MSD 6AL box and a Blaster stock coil replacement and have found VERY little carbon residue on the inside of the exhaust tips. Thanks for any advice.

 

I can't believe that 41 people can look at this and not have an answer or a suggestion. I think you have to pull of the vacuum hose that runs to the regulator and look at the reading on the gauge at idle. Is it supposed to read around 43-44 p.s.i.? At idle now, I have a reading of 50 p.s.i. with the hose hooked up and I heard that's what it would read at W.O.T. This gauge is right next to the adjustable regulator. It does idle smooth with no smell of it being over rich and the tailpipes stay quite clean. Would really appreciate it if somebody could give an idea about how much you can raise the pressure with the stock injectors.

 

pressure on the 350 with the stock injectors should be around 43.5psi

 

ed what you need to do is get the car dyno tuned. I did everything you have done on my 89 a long time ago and got good results. What really made the car run well was a good dyno tune with the car on the rollers.