89LXStang

Just put an afpr on my car.Where's a good place to start for settings on the old girl.

Stang Seller

Whats done to the car? If its stock h/c/i then try about 37psi with the vacuum off.
SS

89LXStang

Gt40 heads,F-303 cam and I'm running the cobra upper and gt40 lower.Still have 19lb injectors to.

Stang Seller

Well, its trial and error. I would suggest 42-44psi and play with it from there. Leaner = more power, but not too lean. Absolute best way to know you're safe would be with a wideband O2 but most people dont have access to those. I think start at 44 and work down and see how the car likes it best. Also, if you've never had them injectors flushed take them to a reputable shop to have them professionally cleaned.... it makes a very nice difference when the injectors have over 100k on them.
SS

89LXStang

Thanks for the info Stang Seller......................

89LXStang

Just checked the pressure with the stock reg still on and the vacum line still on.It's at 42 psi.Should I go up or down when I finish putting the afpr on??

Stang Seller

Without the vacuum line on, I bet you'll be reading about 37-38psi.
SS

89LXStang

Didn't change when I took the line off the stock reg.Stayed the same.What's with that is the stock reg pooched.If it is I'm glad I got the new afpr to put on.

Schlodes

Yes, very likely the stock regulator is pooched if pressure didnot change when you removed the vacuum line.

With your mods, as Stangseller said, start around 44/45 and work your way down. Good way to tell would be to go to the track and pay attn to the cars MPH and make the changes accordingly till you get it to where the car MPHs best. Or go to a dyno..

89LXStang

Thanks for the info.I will be trying your ideas as the new adjustable is on now.