Fuel Pressure regulator----->

[Guardsman]

Anybody know if the PCM will accept the fuel pump and pressure regulator from a Z28? In the service manual, fuel pressure for the L36 is suppoed to be 43-55lbs, the LS1 is supposed to be 55-61lbs. I'm wondering if the PCM controls the regulator?
While I'm on the subject, has anybody figured out what the flow rate of the stock injectors is yet? I've read 19lbs/hr and 22lbs/hr now. I dynoed my car at a max of 169rwhp, and giving it a 20% loss (A4), that puts me at 211hp at the crank. If that's accurate, that's way above what 19lbs/hr would support (182hp), and right at the limit of what 22lbs/hr injectors would support (211hp).

[John_D.]

The pcm shouldn't care about the fuel pump or the regulator, not directly anyway. As long as they bolt up, you should be ok. The regulator is vacuum driven. At idle (20 on the vacuum gauge) the fuel pressure regulator holds around 40psi. As the intake vacuum drops, the regulator lets the fuel pressure climb anywhere from 44psi (about 10 on the vac gauge) to 48psi (at about 2 on the vac gauge). On my '98 anyway...

When the nos kicks in, it applies some pressure to the vacuum fitting on the regulator, and the fuel pressure goes up to 60psi.

The net effect of the higher fuel pressure will be the injectors flowing more, to behave as if they were bigger. So you may have a tendency to run rich at idle. At cruise the pcm will read the o2's and hold steady by reducing pulse width. At wot you may run too rich also.

I would suggest using something (autotap, obd2, a gauge, something...) to monitor the o2's, at least initially, if you kick up the fuel pressure. You may need a maft to fake out the computer to hold the injectors open for a shorter period since they will be flowing more. Just to fine tune it. Because it won't monitor the o2 sensors at wot.

[Arctc Wolf]

depending on the mods you've done to the car, a higher flow fpr and fuel pump will do you some good. If you do a few intake and exhaust mods, the increased flow will keep the injectors from going above 80-85% open. The computer will adjust as long as you increase the fuel pressure slowly and at small incrememnts. later on, you'll want to get some programming done so you can run w/ bigger injectors instead of increasing fuel pressure. A maft and autotap will work well for at-home tuning of everything at first, so I suggest going that route before spending a lot of cash for custom programming(unless hypertech comes out w/ a programmer for your car)