Rich Backfire?
Rich Backfire? when i ran leaner around 13.0 afr i didn't get this sound that i believe is backfire.
i've been tuning to go to 12.0 down to 11.4 during a run and have been noticing this sound that i thought was the solenoid surging but i've read that there is such a thing as a rich backfire? i get it on the track and street rolls.
i think it might be a rich backfire due to:
1. kr increased to 3-4* when i took timing out for 1* of kr that came up.
2. my inj DC moves +/- 5% even though my afr stays pretty flat.
3. inj DC does not follow the rpm incline until 3rd(?) gear which starts around 85-90mph when going from a dig.
4. i believe the nitrous is being read by the maf correctly because on a Dry 80(1st) and 55(2nd) the maf hz will go 10k-10700hz and NA will only see 96xx hz. dynamic cylinder air is logging as high as 1.1x on spray and NA will only see to about .82.
whatever tune i run whether it be 13.0 or 11.5 afr, NA will be fine and inj DC follows the rpm incline and very little(.4*) of kr or none at all.
i'm hesitant about bringing the nitrous afr up but more worried about this backfire. plugs have been changed in the past 1k miles. #8 seemed a bit dark but the gap was still the same as when installed(.38).
i've been tuning to go to 12.0 down to 11.4 during a run and have been noticing this sound that i thought was the solenoid surging but i've read that there is such a thing as a rich backfire? i get it on the track and street rolls.
i think it might be a rich backfire due to:
1. kr increased to 3-4* when i took timing out for 1* of kr that came up.
2. my inj DC moves +/- 5% even though my afr stays pretty flat.
3. inj DC does not follow the rpm incline until 3rd(?) gear which starts around 85-90mph when going from a dig.
4. i believe the nitrous is being read by the maf correctly because on a Dry 80(1st) and 55(2nd) the maf hz will go 10k-10700hz and NA will only see 96xx hz. dynamic cylinder air is logging as high as 1.1x on spray and NA will only see to about .82.
whatever tune i run whether it be 13.0 or 11.5 afr, NA will be fine and inj DC follows the rpm incline and very little(.4*) of kr or none at all.
i'm hesitant about bringing the nitrous afr up but more worried about this backfire. plugs have been changed in the past 1k miles. #8 seemed a bit dark but the gap was still the same as when installed(.38).
A rich backfire is when you have unburnt fuel and the car will pop out the exhaust. At 11.4 to 12.0 you are not to rich.Try closing the gap on your plugs to 34-35 and see if it goes away. Other wise you have a issue within the tunning perimeters of your car.
Dave
Dave
Dave's on track, and one more thing to consider, some guys will get back firing when coming off the spray and snapping the throttle shut? On your knock retard, day to day this can change for many reasons, so removing 1* was evidently not enough. Sounds like your getting pretty close on your tune concerning your a/f.
Robert
Robert
