Fuel Pressure for (mostly) stock 5.0

[50bomber]

Sup, nubee here. However, long time lurker and proud 5.0 owner. My main question concerns fuel pressure that a mostly stock w/few bolt on car would need. What is the pressure from the factory? Do stock cars respond better to lower or higher pressure? One last question, what should the pressure be WOT, since the vacuum line is connected to FP and more intake vacuum would enrich the mixture, however to what pressure? Ok, one more, Would an aftermarket intake/heads alter the manifold vacuum, therefore, scew up the pressure? Thanks for any replies and I apologize if this is a repeat, however, I haven't seen any threads about this in a while, and the search function is disabled for some unknown reason

 

[HISSIN50]

im not a FP adjustment fan on stockish motors. the EEC is very adaptive. if you fatten up the FP, the puter will shorten the injector pulsewidth (it corrects itself).
too little pressure will cause a wider pulse, but not-so-good spray.

if your pump can keep up, WOT should be about what you have the base FP set at (set with the vac line off) - as you have little vac at WOT.

here is where i get murky. ive read that the puter can trim fuel at WOT and ive also read that the puter cant trim at WOT (no O2's to read from, but perhaps it reads from previous runs - that is what im not sure of). so some guys bump the FP up, so that at WOT the pressure is greater (injector pulsewidth lessened though?). but if the puter adapts, i dont see the gain.

fuel pressure goes up inversely to higher vacuum. so if your cam does not create as much vac, the pressure would be the same or slightly increased (i dont know the thresholds and progressivity of the pressure increase with diminished vac).
im not much of a puter guy - im sure others will have lots more info.

good luck.

 

[50bomber]

Thanks, zang, instant reply, now I feel special The reason why I asked the question in the first place was that I have heard that MAF(89-95) 5.0 come from the factory with a mixture that is a little too rich,hence one of the reasons that they don't quite run as well as the SD car stock-for-stock. I was wondering if that is true or some bench racing garbage? So if you leaned out a MAF controlled car a little, you would stand to gain back some of the lost HP. Is my logic flawed? BTW, thanks for the very timely response, HISSIN50

 

[Look Its Aaron]

I say stick with the stock 39.