I was just wondering if there was an ideal A/F ratio throughout the RPM range or it depends on what RPM you're running. If it depends, anyone have any idea what that would be in 100RPM increments?

no.

there is an ideal AFR CURVE for a particular engine setup...outside of that, the AFRs vary between load sites, amount of boost, rpm, TPS, etc.

look up micks tuning guide or download turboxs' manual for the utec. thats a good place to start.

Bosche seems to think that most engines make most power between 12.5 and 14 to 1 a/f ratio(on gas)...... If an engine's running richer then 12.5 to 1, ya know that more power could probably be made by leaning the a/f ratio out to 12.5 to 1. The problem is that many(if not most of us) of us can't do that for one reason or another(like being octane limited or whatever)), and we're stuck with a/f ratios which are richer then what's ideal.

peace

I was just wondering if there was an ideal A/F ratio throughout the RPM range or it depends on what RPM you're running. If it depends, anyone have any idea what that would be in 100RPM increments?

It's really boost or no boost not rpm.

At zero load, or minimal load (I.E. cruising) you'd probobly want to maintain stoichimetric for the majority of the RPM range, with an enrichment >4k for example.

As load changes, an ideal AFR range will change, through out the RPM range.

So if you HAD to have one solid AFR from 1-7k rpm, I'd say it have to be done 3 dimensionally

AFRxRPMxLOAD.

That's about the only way you'd safely get away with it.

Jorge (RiftsWRX)
www.ProjectWRX.com

deja vu, all over again

This covers the basics pretty well. The guy is probably a member of NASIOC. Figure 3.8 is the classic AFR figure:
www.hss.cmu.edu/philosophy/programs/undergrad/logic_comp/Graduates/2002/yang_thesis.pdf

This deals more with timing and what MBT really means, excellent paper:
www.visteon.com/utils/whitepapers/2003_01_3266.pdf

Another good AFR/Timing read is here. It also has some fundamental links. I believe this piece was written by NASIOC member SaabTuner:
http://www.saabscene.co.uk/ubb/ultimatebb.php?/topic/23/1194.html