What is the ideal fuel pressure at wot for a 509 with a holley carb? I was previously seeing 6psi at idle and 1psi at @wot. I just ordered a new fuel pump and regulator and want to make sure pressure gets set correctly
Was I losing top end only being at 1 psi?

at 1 psi at wot it is detonating.you need 6.5 imo at wot.

Yes, and probably the piston tops and ring lands too.

edit in: your oil temps where probably going real high too.

I do not even see how you can reached WOT with 1 psi FP. The engine should be fallen on its face if this a true reading of 1 psi.

All WOT requires is your throttle to be wide open. You can even do this with the engine off. LOL. :wink:

Ideally your fuel system should be set up to maintain 6 psi from idle to WOT. This should not be difficult with proper line size, good fuel pump and a regulator. At 1 psi it is not able to keep up and you will run the float bowl level down and run very lean.

I gained 6mph when I junked the Holley red pump giving me ~3psi at wot and went back to the stock mechanical unit giving me 6-7 at wot.

Baja, what kind of mechanical pump are you running? Regulated?

Not regulated - just the stock unit that came on the 454 Mag MPI. It still keeps 6psi at wot on the 502/500hp motor.

What kind of pump/regulator setup was this??