View Full Version : Supercharger (Lean Condition)

06-18-2005, 06:44 PM
I have a 1987 IROC that used to have an 305 TPI and I put a 1992 Vette 350 TPI into. I kept the MAF system as I wanted to put a good cam in it, I used the stock 350 injectors that come with the original block. edelbrock headers, SLP high flow runners, edelbrock high flow intake, Then I put the vortech S/C @ 8 lbs of boost, The computer went into a lean condition that dumped all the pressure into the base. I found numerous problems with the vette motor during tear down from bad bearings to all the piston rings gaps were lined up so that would explain all the base pressure. I recently bought a Jet adjustable fuel pressure regulator. I had the heads redone and am still not happy with them as they are 94 vette 58cc heads now with stainless valves. I do not want to lean this motor out again. I know that I need idealy air/fuel mixture of 14.7:1. Using Wide Band or stand alone monitoring of O2. How can I get this out of the lean mode that it went into before? Everyone I have talked to said I might want to get the E-PROM reprogrammed. But, I have also heard that I can adjust the pulse width through the ecu to the injectors. I am still in a learning process with S/C's.

I don't have all the pics posted as of yet.


D Rock
06-19-2005, 12:13 PM
You do not want a A/F of 14.7:1, the best ratio for the most power is around 12:1 but i would run about 11:1 on a supercharged or forced induction app.

06-19-2005, 06:22 PM
Ok, That makes sense. I didn't think of 11:1 as the best A/F mixture. But, As a fairly new S/C user. How would I get to that A/F mixture. Can I do it mechicanically or does it have to be done through the computer, and How? Thanks much

06-19-2005, 06:59 PM
He means 11:1 A/F at WOT, not all the time. You probably know that but just in case. Also, many larger cams are not happy idling at 14.7:1 either. They may much prefer 13.5 or so at idle yet cruise happily at 14.5-15:1. Don't get stuck on the numbers, give the engine what it wants. But keep your wot A/F at 12:1 or richer to be real safe.