Fuel Pressure
Thread Starter
Racer
Joined: Apr 2002
Posts: 353
Likes: 0
From: Tuscaloosa AL
Fuel Pressure
I have an '88 4+3 coupe. the engine has; cold air induction, 52mm TB, ported plenum, BigMouth manifold LArge Tube Runners, balanced bosch injectors, GN fuel pump, MSD, AIR pump delete, 1.6 roller rockers, true dual exhaust, and the usual "minor" parts upgrades. I typically set my fuel pressure at about 50 psi @WOT (vacuum hose removed) which usually equates to about 43 psi at idle. What do y'all think/do? Also, I am rebuilding the motor with a (planned) ZZ9 cam and mini-ram - should I adjust fuel pressure any? :steering:
Safety Car
Joined: May 1999
Posts: 3,651
Likes: 5
From: Atlantis
Cruise-In I Veteran
Re: Fuel Pressure (Mark L. Warner)
I think you may need to do some monitoring of your ECM data.
Pose this question over on the ECM/Tuning section and you'll get a WHOLE LOT of information on why it's not too good an idea to just arbitrarily set the fuel pressure without knowing what the engine needs and wants.
There's a LOT of incorrect settings you could use erroneously....the correct or best setting for your engine can only be found through some research.
Good luck with it.
Pose this question over on the ECM/Tuning section and you'll get a WHOLE LOT of information on why it's not too good an idea to just arbitrarily set the fuel pressure without knowing what the engine needs and wants.
There's a LOT of incorrect settings you could use erroneously....the correct or best setting for your engine can only be found through some research.
Good luck with it.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Fuel Pressure (Mark L. Warner)
I assume you also have appropriate exhaut mods to assure good air flow; in which case your FP sounds about right. With my mods I run 48psi using stock 22lb/hr injectors and my A/F ratio at WOT is close to 12.6:1 on the dyno and 920mV on the scanner.
A dyno with a WB A/F gauge would be best for tuning after those new mods, a scan tool will help or some passes at the local drag strip. I wouldn't go above 55psi on the FP though; if you need more flow move to larger injectors.
With that cam you might consider pocket porting and working your #113 heads instead of the mini-ram. Check out the L98 mods results data on my site to see what you would gain from the two add ons.
A dyno with a WB A/F gauge would be best for tuning after those new mods, a scan tool will help or some passes at the local drag strip. I wouldn't go above 55psi on the FP though; if you need more flow move to larger injectors.
With that cam you might consider pocket porting and working your #113 heads instead of the mini-ram. Check out the L98 mods results data on my site to see what you would gain from the two add ons.
