whiteghost7

iTrader: (1)

Running a demon blow through 750cfm carb w/ annular boosters on a 9:1 sbc chevy witha p1sc procharger @8lbs. I installed a racetronix 255 lph forced induction pump in tank through the stock fuel lines on my 92rs. An aeromotive fpr controls the pressure and boost referencing. My problem is that the carb doesn't seem to respond to jetting or power valve changes with regard to richening the mixture to a safe level. The car runs fine wwith excellent drivability at all sppeds but the afr stays at around 14.0 at wot no matter what I do. Current jetting is 74, 82 w/ 5.5 power valve. The car pulls very well and the mixture does richen up slightly up top (annulars responsible for this I think) Does anyone know the best way to test the fuel flow rate to the carb? I am basing my Afr's on an edelbrock gauge and on the tailpipe sniffers used at the dyno. The first tuner I took it to after the install jetted it all the way up to 92's on the secondaries without a discernable decrease in the afr? Any and all suggestions are welcome. Baseline pressure is 5psi and Float levels are set on the high side. I don't experience any detonation that I can hear and am really puzzled by this lean afr. Shouldn't my cast pistons hav cracked by this point (1 year full of aggressive driving) ? Also running an MSD 6AL with Boost Timing Master control and retarding timing 1.5degrees per pound of boost. initial is 10deg btdc and total is 28deg all in at around 2800rpms. Help!

whiteghost7

iTrader: (1)

Anybody? ttt

5678TA

more pressure.. i run 6-6.5psi.. but i'm N/A.. 750 mighty demon annular though..

but try more pressure

whiteghost7

iTrader: (1)

I've tried baseline fuel pressure's from 4-9psi. Changing the pressure doesn't seem to have a very noticable effect on the afr. I think I'm getting a flow obstruction somewhere. I'm using a new sock filter attached to the in-tank pump and a new gm oem in line filter. Does anyone know approximately how much fuel I will need to flow to support 550hp? Assuming typical BSFC for a 9:1 350sbc with a mild 212/222 @.050 .435 .465 lift cam in a supercharged application. Keep the suggestions coming.