Originally Posted by
Vadim That's weird, not sure what it could be then, I might give 4 bar another shot, maybe it needs more timing or something.
I'm no fuel madman or tuning genious, but from what I remember, it's not how you adjust timing or anything else.
The difference between 4bar and 3bar is overall MAXIMUM gains you can expect, as in pushing the envelope. Remember, that your fuel pressure rises as boost rises. Hypothetically, you could run your 370's at 5bar (given fuel lines can handle the pressure, and your injectors have been flow tested at such pressures), and would be able to make a MAXIMUM of ~328whp at ~73.5psi of fuel pressure, all on 370cc injectors. Now, on top of that (assuming the FPR is at a ratio of 1:1), you'd increase the fuel pressure 1psi per each 1psi of boost acheived.
So, at ~84psi of fuel pressure at 10psi of boost, you'd be able to peak at ~345whp.
Edit: Cliff's notes (:rofl
- Raising fuel pressure, all other things the same, does nothing for power, but works for economy and emissions. Same volume, just more atomization (finer mist).