: Fuel Pump Limitations?



camslambam
04-18-13, 05:17 PM
Hey guys,
I've been looking around for last few days and for the love of me can't find stock fuel pump limits.

I'm running 850 injectors. 606/575 12psi on 87 octane. 640/600 on race fuel.

Car with all nannies off seems to have sluggish 1-2 shift (paddle shifter). It seems almost like car goes into 1.5 gear before finally going into 2. Very noticeable sputter. Not sure if pump is cutting off at higher rpms or what?

Da V-Man
04-18-13, 06:30 PM
Sounds like you're hitting the rev limiter fuel cutoff. Try letting the tranny shift itself in sport mode.

cruiser68
04-18-13, 08:54 PM
87 octane ...ugh

On my latest round of mods my tuner said I was dropping fuel pressure at wot on the dyno. Said he could tune around it or add a bap. I chose the bap. I think he said it was dropping to 55psi. Has run fine for the couple weeks I've been driving it. No track time yet this season.

Mods are Kooks headers w/ cats into stock mufflers, intake, LS7TB, GT11cam and springs, 2.5/9.1 pulley, id850, HX and pump, norcal HX box. 610whp/606wtq

wait4me
04-21-13, 02:03 AM
Your question has several answers, and those answers depend on several different outcomes depending on the tuners abilities.. We have made 1000RWHP with the stock pumps. However, people will argue with that..

Voltage is a main contributor to the fuel pumps output, as well as the internal fuel regulator. Changing those things will net totally different max amounts of fuel. Also diameter of tubing for those said pumps as well...

If you get the voltage near 17-20V and modify the fuel regulator in the tank, you can get 900s no problem without pressure drop if you do it correctly.