AFPR Tuning Question

[importracr317]

quick question- kinda newbish....
when you install and adjustable fuel pressure regulator, is there a set base pressure you need to turn it down to? Like- you buy an AFPR so you could turn the fuel pressure down to XX psi, which is XX psi less than the stock FPR, and its the same for every car, regardless of injector size and fuel pump as long as it increases in a 1:1 boost psi to FP psi? Or do you need to adjust it based on each car's individual need.....
Hopefully my question is clear.
I'm looking to get the aeromotive unit with an underhood FP gauge, and I just wanted to see if I'm going to need to do a ton of tuning with the regulator, or do i simply turn it to like, 63 psi, and then tune the AFC.
I've had a tough time getting my car lean enough past 5K with my 660's and 255. I figured the AFPR was the next and final step to the fuel system tuning.
Thanks- sorry for the long post....

 

[Mike 99GSX]

Stock fuel pressure on a 2g is 43.5PSI without the vacuum line connected. This is where you should start. You can alter fuel pressure to play around with a balance of getting the A/f Ratio where you want it and altering the AFC enough to get in the correct timing map that you want. For example, if you had your timing advance in good shape with the AFC but your A/F ratio was still rich, turning down the FP will bring the A/F ratio down and if you don't touch the airflow signal(then the timing will not be effected). The problem with this is that you really need a wideband O2 to accurately get the A/F right. The reported narrowband output of the 2g logger is not accurate.

 

[importracr317]

I'm looking into that AMS wideband kit- I assumed it would be better than tuning with a logger, since most of the logger I know of give you the O2 sensor voltage and you tune according to that- which everyone knows is hardly accurate.
I figure a wideband kit and an AFPR, coupled with the AFC would work pretty well to fix my high end 10.2:1 or so A/F ratio and overly rich idle conditions as well.