Fuel Pressure

[WDRacing]

For the guys who want a few more lbs of boost but don't want to invest in a whole new set of injectors. You simply buy an adjustable fuel pressure regulator and crank up the fuel pressure, assuming you can trim the duty cycle off boost. Running 55lbs of static fuel pressure instead of 43.5, or whatever stock is, will increase your flow quite a bit. Here's a link with a calculator to play with.

http://www.csgnetwork.com/fiflowcalc.html

WD

[andrave]

yeah and if you have something like a JWT ecu that doesn't allow for adjustment, its a decent way to fine tune your a/f's... wait, not so much "fine tune."more like modifying your entire fuel map. but yeah.

[nizmo240sx_22]

That's what I was planning on doing. The only thing I will have is the jwt ecu. So once I get a wideband I planned on tuning it with a fuel pressure regulator or if I found an extra $200 an safc

[IvanAtSPRacing]

Actually, the block learn (short term / long term) fuel corrections should take care of off boost fueling. They will just end up in the negatives. Its a band-aid way to get more gross fueling, but it works.

With our stand alone tuning, we use fuel pressure to compensate for injector issues all the time. With a bunch of Supras running 160lb / hr injectors, to get them to idle, we actually run 35 psi base fuel pressure. With 72lb / hr injectors and a customer shooting for more then 700 whp, we will actually run 55-60psi base fuel pressure.

[andrave]

damn. 65 base pressure equals what under boost??

[WDRacing]

Close to 100 under full boost...

[Nismo_Freak]

Base FP is 34psi.

[WDRacing]

34-43 whatever...

[Nismo_Freak]

43 psi is the WOT peak under no boost.

[sil80drifter]

aren't you scared that one day your fuel pressure lines will burst and fuel will spray everywhere at a presssure fo 100psi? not a pretty thought. especially under full boost.Those beetter be some sturdy *** fuel lines.

You'd think that with standalone management you would be able to control idle issues without resorting to fuel pressure regulation, and using pulsewidth instead.

sil80

[IvanAtSPRacing]

aren't you scared that one day your fuel pressure lines will burst and fuel will spray everywhere at a presssure fo 100psi? not a pretty thought. especially under full boost.Those beetter be some sturdy *** fuel lines.

You'd think that with standalone management you would be able to control idle issues without resorting to fuel pressure regulation, and using pulsewidth instead.

sil80

Even the rubber reinforced fuel line (not braided steel) is rated at 300psi.

You can control a lot with PW but min PW on a large injector can still provide too much fuel for idle. When your injectors are just too small for the HP your shooting for, you can elevate base pressure and get more fuel out of them.

[toki]

I have my base fuel pressure at 40psi right now and a 1:1 FPR, and my s-afc correction are too drastic for my liking right now, like the -35 range, should I just turn base fuel pressure down to around 35 and re-tune? (It's got a 10min tune as it stands, no big loss.)

[WDRacing]

Are you running 370's?

[toki]

460s

[ultimatuc]

you do not want to go over 75psi on the injectors. it makes it harder for them to close completely and shortens their lifespan.