TDMKR496

iTrader: (3)

What is a good base fuel pressure on an LS1? I have a 5.3 with an LS1 intake, 80lb injectors and aftermarket rails and fpr, just looking for some thoughts as to what the fuel pressure should be, thanks!

Old Geezer

iTrader: (3)

I'm pretty sure the injs are rated @43.psi, and the stock LS fp is 58-60.
If you need the injs to flow 94+#, then run at 60. If 80# is sufficient, use the 43.5.

Blown06

iTrader: (32)

For stuff that has plenty of pump, I run them at 58 psi. On high power stuff, I typically run 43 lb base pressure to help the pump flow.

soundengineer

iTrader: (16)

more pressure is not better in most cases...
it is always better to buy a bigger injector and run a lower pressure
fuel flow and fuel pressure are inversely related
as flow goes up, pressure goes down
as pressure goes up, flow goes down

so when you make 95 psi of fuel pressure, you total fuel flow has gone down drastically from stock..
its much better to start at 43 psi fuel pressure and buy bigger injectors so that you potentially stay below 70psi fuel pressure

also, most pumps, are not made to do those big pressures and fuel flow falls off drastically past 75-80 psi....meaning you actually run out of fuel way sooner when you get above 80psi
at 43 psi your pump may be capable of 600 HP
but at 95 psi its going to be done by 450 HP because it cant flow enough fuel when the pressure is turned way up.