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Normal A/F Mixture Rate

1674 Views 15 Replies 6 Participants Last post by  Mana4Real
I have a o/r xpipe and i know my cars most likely running rich, whats the normal air fuel ratio for a car with my mods (mods in sig) so i can adjust it using my lap top and predator.
let me know thanks
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Twitch said:
Just came back from the track tonight. Since I did my dyno run, I saw taht my A/F ratio is around 12:1 - 11:1 which is rich. The mechanic suggested me to lean out about 5%, but too be safe since I have no A/F ratio sensor, I leaned out 2k-4k by 1.5% and 4k-6K by 3%.

After 10 runs, I couldn't do ANYTHING under 14.0xx, my best trap time was 102.8mph.

After I reseted to original Predator settings and ran again. First run, 13.984, second run, 13.875, then third run 13.873 and my trap speed improved too. My best of the night was 103.273

So I dunno what's happening, maybe my A/F ratio at the dyno was off.

My mods are:
- Mac ProChamber O/R
- Diablosport Predator
- Granatelli Intake Plenum
- Ghetto CAI:tongue
You've got to remember that when the engine is under a heavy load it likes a richer A/F ratio. At the track and at the dyno you are running at full throttle and the engine wants more fuel. During normal driving conditions, the engine prefers a higher A/F and the computer will lean the mixture out.
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