Ok this has been talked about before,but i fitted an adjustable reg and was looking at fuel pressures on standard fords (el,ef,au) and where talking a big jump in psi for cars that are not that different,39psi up to 51 psi for my vct XR6 any body had a dyno tune with a adj reg, and if so what is your current setting, every car will be a bit different but there would be a good psi,i guess anywhere between 40 and 50 psi?.Got it at 45 now and seems ok,car has walbrow pump and standard injectors,and the melpassi reg. thanks....

XR6 fuel pressure is generally 300kpa, or 3 bar, increasing the fuel pressure will make it run rich and will not gain any more power.
Unless you have a wideband o2 sensor to see what the a/f r's are, best to leave it at 3 bar (44psi) as that is what the ecu is base calibration is programmed for.
Changing the fuel pressure will cause the LTFT's to move, and there is a limit to how much the ecu will compensate.

so 45 psi is close enough,the car was last dynoed with the 3.5 bar vct reg,so maybe a tune to make the most of the adj reg is in order.3.5 is closer to 50 psi, to high i would think.Thanks i am on the right track then (i hope).

Is it best to set fuel pressure level with vacume hose on or off the reg.Done it both ways (after asking around) was told more times to do it with hose off.Car is hard to start,takes a few times to kick over.I have set the pressure level at 45 psi i think thats close,when i put the vac hose back on it shows about 35 psi at the gauge.Thinking maybe move the gauge? any ideas.

Ok i just changed the guage and they show different psi. Chinese! and the speco one has leaked all its fluid out! I have moved the gauge to the side of the reg because the in line fitting i had was leaking,but i cant see how it would make a difference,any one dissagree?