svtash1

I recently got on the dyno after installing my C&L and pred tune. I was supposed to get two pull but they only gave me one because they said I was running lean. So I am wondering what everyone elses A/F are with the C&L and tune. Here are my numbers. Are they actually lean cause I ve seen other dyno charts that arent too different than mine. Car runs just fine and doesnt throw any codes. Just trying to get a general cencus of if this is lean and what it should be around. I also thought the hp/tq #'s were a bit lower then other I have seen with the same set up. Im not sure though Im pretty new at this.
Thanks In advance.

MSP

The answer is that the specific energy, not the heat value, determines the potential for a fuel to generate power. If more fuel can be burnt effectively with a given amount of air then more power will result, but this should not be taken as meaning that just adding more fuel necessarily always means more power. The stoichiometric (chemically correct) air/fuel (A/F) ratio for gasoline is approximately 14.7:1 but best power is achieved at richer A/F ratios around 12-13:1. This is partly because of the charge cooling effect of the extra fuel and also because the presence of slight excess fuel means all the air in the charge will be burnt. Further enrichment beyond this point will cause power to fall. If gasoline were treated to contain oxygen then the stoichiometric A/F ratio and that for best power would reduce because the fuel would then need less air to form a combustible charge. It would therefore then be possible to burn more fuel and the specific energy of the charge would increase accordingly. Oxygenated compounds such as MTBE (18.2% O2 by weight) are sometimes blended into racing gasoline for this purpose as well as for the increased resistance to detonation. It should be remembered that air contains only 23% oxygen by weight so quite modest additions of oxygenates to the fuel can make a measurable difference.


http://www.jagweb.com/aj6eng/superchargers.html

DallasStang

No offense meant at all. But. . . huh? :scratch:

Your talkin' way above me know. :worship:

svtash1

So According to this I was not running lean I was actuallyt running a little rich. Correct? By that definition leanre shoulbe 15:1 or higher correct? Or have I just confused myself with the lengthy definition? :scratch:

RPM

Looks lean to me.

stkdidy

i see 12.9 to 13.9...which means its a bit too lean

should be more 12.5-13.0

The Boss Hog

Your A/F is just fine for a n/a setup. If you were boosted then you would want it a little richer, but you're not so its just fine.

The Boss Hog

I8URVTEC

My A/F with JLT CAI was 12.471 and stayed within 1% of that through the pull.