kev2369

Just installed an adjustable fuel pressure regulator. Didn't necessarily need it but it will be handy for future mods... anyways, i have a 65mm throttle body, gt40 p&p heads, full length headers, comp cam with 270/276 duration and .512 lift. Question is what would be a good fuel pressure to run. Before it had about 25 idling and would go to about thirty when you reved it up, but i set it to forty and it jumps to about 48 to 50. Just wondering if anyone had any idea where it will help me the most. I haven't tried to raise it higher than that so i don't really know how it will act. Figured i would try to get some advice before i cranked her up any more cuz i don't know if it will even help. Thanks for the input.

93must

If your car ran fine with the stock one on I would set it at 40 with the vacume line disconnected. And then hook it back up.

JeffUtica

Adjust the FP to 39-40 psi with the vacuum line disconnected. Sounds like it's going to 48-50 because you didn't disconnect the vacuum line. Under zero vacuum you should see 39-40 psi which is fine for your setup. This should keep A/F closer to stoich (14.7:1 air fuel ratio) and return your fuel mileage closer to stock as long as you're not always in WOT.

kev2369

Alright... I appreciate it... I left the vacuum line disconnected... I tried it out and couldn't tell much of a difference after installed, but like i said, it will be an extra amount of comfort when the planned charger goes on.

JeffUtica

You disconnect it temporally to adjust FP, then plug back in.
When it is disconnected, plug the hose with a golf tee or equivalent so you don't have a vacuum leak while the car is running.