Fuel Pump
sykotic1
04-18-2004, 02:35 AM
Any benefits from using a higher pressure fuel pump on a slightly modified 305 tpi (exhaust no cats, ignition, intake)? ive heard using a 15 psi pump (pph? gph?) max could add some power safely.
4onFloor
04-18-2004, 09:40 AM
tpi is more like 45psi. but not really any advantages unless you've got higher rated injectors.
sykotic1
04-18-2004, 10:34 AM
people have told me i dont need bigger injectors unless i really get radical with the project. also ive come across manuals that tell me the pressure is regulated in the fuel rails at 45 psi and that is what my stock pressure should supposedly hover around, and then when i look at people using aftermarket fuel pumps it usually centers around 7-15psi. just somethin else im tryin to make sense of.
4onFloor
04-18-2004, 10:36 AM
15psi is for tbi. and yes your right, you dont need bigger injectors unless you'v upgraded ur induction.
sykotic1
04-18-2004, 10:48 AM
i see. http://www.gmhightechperformance.com/tech/0403htp_chip/ - that article is giving me some ideas, not so much as strictly increasing fuel pressure but what else needs to be done to compliment it or should i say what it compliments. what do you guys think? if i replaced the chip or did some head/cam work would that give an increase in fuel pressure some more purpose?
4onFloor
04-18-2004, 10:59 AM
ya ur on the right track. do some mods but the only way your gonna know if you need more fuel pressure and or volume is to get a fuel press. tester. plug it in to the service port on the fuel rail and turn on the ignition. should be 40-47psi. then when you start the car it should drop 3-7psi, if it drops more than that, then yes i would go with a bigger fuel pump. also you can get an adjustable fuel regulator that goes in place of the stock one on the fuel rail, and you can squeeze everybit of pressure out of that stock fuel pump.
sykotic1
04-18-2004, 08:27 PM
that something else ive never been entirely sure about. a fuel pressure regulator lets me adjust the pressure right? so without putting on a new pump or anything i guess i could still get it working to the max like you said.
4onFloor
04-18-2004, 08:35 PM
dont think the stock regulator is adjustable. you might be able to get a different spring for it, but that'd be kinda hoping and poking. i've seen replacement adjustable regulators for about $35 except you gotta have a weird torx bit with a hole drilled in the end to get the screws out
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