Hey guys, I'm new to this board, but not to F-Bodies, I've been hanging around on the UFBA Website for a couple years now. Anyway, I bought an adjustable fuel pressure regulator the other day, and I was wondering how high I can crank the pressure with my stock injectors and fuel rail. I at one point found a website that said I can turn it up to as much as 42 PSI, but I'm not sure. The engine is the Big Bad 305 TPI. Thanks for any help!

 

42-46PSI is roughly what the FP was set at from the factory. Be sure you disconnect and plug the vacuum line from the AFPR when setting the FP or you will get false readings. You can easily bump it up in to the 50s but 50-52PSI should be more than enough for your 305, depending on what mods you have.

 

Right now I have a 3 inch flowmaster catback exhaust, cold air intake, TB bypass, TB Airfoil, ported plenum, and the AFPR.
Another quick question, when tuning it, do I have to have the car running or do I just turn the ignition on? Also, I picked up a fuel pressure gauge that mounts to the shrader valve, can I just leave it on there or should I take it off when I'm done?

 

i left mine on there for a while when we were doing some tests to see if my fuel pump was going south or not... i have a 305 w/ slp y pipe, cutout and such... and i got my fuel pressure set at 50 PSI right now until i can get to the track and play with that and timing some... it feels a little stronger with it up there... and i am getting a little better gas milage... i guess from the better atomoization...

 

Good thats what I was hoping to hear. I've seen a couple of dyno sheets that say with it cranked up to 52 PSI you can 19.8 RWHP and 21.4 lb-ft, whether those are realistic or not, I dont know, but I was hoping to get at least better throttle response. Any tips on tuning it?

 

i was gonna put it on the dyno and see what different pressures and timing did... but don't have the cash... so i am going to hit the track when it opens and just bump it up between runs and do that with every timing set i want... 6* 8* and 10* advanced timing... probably stay between 48 and 52 PSI and see what happens...

 

On my late 305 I had TES headers w/aftermarket cats and 3" Flowmaster catback. On the intake side I had ported and siamesed plenum matched to ported and siamesed(2 1/2" on top)SLP runners w/edlebrock base. That being said at 50psi it ran pretty rich even with the extra flow. Power loss and abvious smell, followed by inspecting a plug. 47 worked the best for me. I beleive 48-52psi is more beneficial for 350s w/similar mods.