hey guys, I have a 502 mag efi with flat top pistions, with cool fuel. and 500hp cam crane roller rockers , emi headers , I was wondering about the fuel pressure? I have an adjustible reg. i have it set at 37psi running with vac line on. seems alittle fat at ide. any ideas?

thanks!

Who cares at idle.....

If it has the stock injectors in it from the 502 they are 44lb/hr and the fuel pressure is set from Merc @ 40-43psi.
I suppose it would be a question for your tuner as to where they set the motor up to run. If you lower the fuel pressure it will lower it across the board which could make melted aluminum. You need to be concerned with where the pulse width was set and at what a/f ratio it was set at for the rpm range you are looking at adjusting. Then it is a matter of adjusting the tune in that rpm block.
Also the pressure needs to be set with it off most likely.

thanks for the heads up ! I'm going to put a gauge on it so i can watch it through the rpm ranges under load. It sounds like it needs to stay above 40 psi..
Thanks..