backman_66

Hey I'm gonna be switching from a stock comptech pulley (5lbs or whatever) to a 7lb pulley which is the 4" one I think. My comptech FPR was adjusted for the stock pulley so if I don't have access to a dyno or any tuning, how many clicks do you guys think I should turn it to compensate for the extra 1.5-2lbs of boost?

Because 7lbs is maximum boost that the stock injectors can handle, and I don't want to exceed that at the moment, nor spend money on extra tuning, so I just want to adjust the FPR. 2 clicks clockwise or so?

mattf87

Not all Comptech FPRs require the same amount of turns, some people have been able to go from a 5.5-6 psi pulley to a 7 psi pulley with as low as 2 turns, and others have had to turn it up to 6 turns. What you should do is get a fuel pressure gauge (check the F.I. faqs/stickies), and/or a wideband air fuel gauge/probe setup. FYI Comptech recommends an idle fuel pressure of 30-34 psi for the stock 5.5-6 psi pulley. My guess is that the idle pressure for the 7 psi pulley should be set around 36-40 psi. Honestly there is no replacement for a good dyno tune, but if you are really adamant about not going to a dyno shop, you should get a wideband and "street tune" it yourself.

--Matt

EK9MAX

On another note.

so if you upgrade to teh 7 psi pulley, will the whole car be runing pig rich because of the added fuel on the FPR?

Like during idle and cruise?

revhi

No, its a static fuel pressure regulator, only adds fuel in boost. I agree, dont mess around, dyno it. I turn mine up and down all day and it doesnt make a big difference at all in my car. I adjust fuel with a piggyback.

EK9MAX

that is good news!