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Old 05-14-2002   #1
GTA Member
Join Date: Nov 2001
Location: Assiniboia, Sask,Canada
Posts: 41

fuel pressure?

88gta, 350 tpi, 38,000 miles. i want to go faster, read you should bump fuel pressure up to 50 psi. i put a gauge on to see whre i was at, 37 psi at idle, 45 psi when floored, which spec is used?

i am going to do this with an adjustable fuel pressure regulator, but is any other part of the fuel system going to resrict this?
-injectors? (unlikely)
-fuel pump?
-fuel filter?

any tips and advice would be appreciated, thanks
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Old 05-14-2002   #2
Owner Of A 88 Gunmetal Gray GTA
Join Date: May 2002
Posts: 18


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Old 05-14-2002   #3
GTA Member
Join Date: Nov 2001
Posts: 210

...well, I am not too sure what you mean by the last question about restriction, but a fuel pressure regulator will not give you gobs of horsepower, but will let you tune your car properly once you start to modify your motor.You can't just install it and set it at 50 psi and run to the track. If you want to check your OEM regulator test it with the vaccum line from the regulator removed and plugged. This will give you a simulated reading at WOT with no vaccum. This is where you want your highest pressure. Both 89 L98's I have had ran around 45 PSI factory. What you have to do next is get ahold of a scanner to check your BML readings, crosscounts ect to see if your car is running rich or lean. This is where the AFPR comes in handy. You can set your pressure to get the proper readings and adjust it as you modify the engine.I know myself I ported my plenum and runners, added airfoil, dynomax exhaust with cats removed, reworked heads and a few little things this winter in Saskatchewan and I ended up bumping my AFPR down to 38 PSI with new 24lb accel injectors. There is no secret number, it all depends on what your car wants. This is why you have to get into your ECM to pull out some readings to see where you are at and what you need to do to get readings all in line. Hope this helps....have a good one!
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