Hi folks, well I got the adjustable fuel pressure and an airfuel sensor with gauge. (I have the lead for traqmate data and will get around to that in a month or two.)

A few questions for you experts:

1. I've heard that the optimium mix is 12.6 to 12.8. What RPM should I check at, does it matter?
2. The measurement is Low numbers=Rich, High numbers=Lean, right?
3. Does turning the screw counterclockwise go leaner? (or vice versa)?

Thanks much!

Eric

Didn't instructions come with the adjustable regulator? It is a little more complicated than that...

Thanks Dave, I got it installed and pre-set. Just looking for at track fine-tuning advice and confirmation of which way to turn fuel pressure regulator for rich/lean.

Eric

You probably want to set your f/p under load. We do it on a dyno, which is convenient since we can use their A/F readings to check against ours.

It's been a while, but I think it's clockwise to increase fuel pressure - that doesn't necessarily have a direct effect on A/F ratio.

I check our cars in 4th gear full throttle at 5000 rpms. Higher number is leaner (15.1) lower is richer(13.1) 14.7 is the middle, above leaner, below richer. Turn regulator in makes pressure higher and richer. Out lowers the pressue and it will get leaner.

Increasing fuel pressure has a direct affect on A/F ratio, with higher fuel pressure lowering the A/F ratio (lower is richer). Generally, FP in the high 30's/low 40's will be close to ideal (high 12's/low 13's). 1/8 of a turn makes about 0.2 different in AF ratio, so minor adjustments can make a big difference. Best is to check under load on a dyno, or with an AF sensor in-car. Should remain fairly consistent throughout the normal range (4,200-5,600). Good idea to start with freshly rebuilt injectors.

breton wrote:Increasing fuel pressure has a direct affect on A/F ratio, with higher fuel pressure lowering the A/F ratio (lower is richer). ...

But it can vary with different cars and intake pieces.