Im not sure if this post should be in this section please dont get upset at me if it shouldnt be, but i think it has to do with my MS tune. I was at the track the other day and iver noticed that my EGT's get pretty hot when i floor it and i get in the upper rpm ranges, on the daily driving tune i have, no i decided the richen the mixtures up in my VE table from 4000rpm- 7000 and from 100kpa up. Im just wondering, i wanted to be on the safe side so i didnt melt anything, so i changed the numbers pretty signifciatnly maybe 8 numbers higher, im just wondering if changing the numbers that much would cause this, should i have just changed the numbers 1 or 2 numbers, would that of been enough and the first run i did it didnt back fire ran great, and then the next run at the top of 3rd it was a loud bang and then the next run it did it at the top of 2nd and 3rd, it seemed whenever i topped out the gear it would do it, it would only do it aroud 6000rpm. Im just wondering if the i increased the numbers too significantly and ive been told that haveing a rich mixture really shouldnt cause a loud backfire like that, and that it could be an exhaust valve being stuck open so i dont kno, and info would be great guys thanx
1996 Black Eclipse GS STAR Stage 2 Turbo With custom equal length manifold and full 3 inch turbo back exhaust 8psi- 9.61- 1/8th mile 14.4- 1/4 mile MS Powered
#2399, "RE: Huge Backfire at 6k rpm" In response to Reply # 0
8 percent up is quite a bit. This can vary, but i've found that 2 percent can be roughly .2-.5 change in A/F ratio. 8 percent was at least one full point richer. Thats quite a bit, and prob enough to get backfires out the exhaust with all the unburnt fuel. Raising 2 percent would prob be plenty to richen it up slightly.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)