Breakdown of AFR's through RPM range
 

I was wondering if any tuner could tell me the breakdown of AFR's you try to achieve on different gases through the RPM range.

I know that 11.3 is optimal at redline for reflashes, it's conservative for 93 octane.

I'm wondering what I should be shooting for at the different RPM"s, or should I be shooting for 11.3 at full boost, what about partial boost, what about partial throttle?

I would also like some insight as to how I should be tuning for c16, I've heard that you can go leaner, but I've also read that DynoFlash AL makes his AFR's the same even on race gas to stay super conservative.

Any help would be appreciated.

It is a very complicated question you ask :)

It also depends on the timing.. with more timing you might need to run a little richer or vica versa. With C16 you will lean the car out ALOT just to keep the AFR the exact same... the fuel is much denser.

You could run it leaner also but it all depends on the car. On my DSM for some reason with C16 I can hit 13:1 (Which is much leaner than most can get away with). My Evo likes to be at about 11.5 at 5k tapering to 12.2:1 at around 8k (SLIGHTLY richer with pump but not by much). Part throttle will depend greatly on much boost.

Here is kinda a run down of my AFRs on pump.... WOT starting at 2k is at 13.8:1 and holds it there until 4k at which it starts to taper down to 11.0:1 at 4.75k and holding that or slightly gaining until 5.3k. It then goes from 11.0-11.2:1 to 12.0:1 at 7.3k and holds it there until 8k.

If yuou are using Meth it should be richer. (Which perhaps is why Al's AFRs are the same on race gas... alot of Meth?).

I hope that helps somewhat. And if you throw in C16, just to keep the AFRs the same you will probably need to pull 10% or more.

I can already see all the tuners chimming in to teach us all how to tune our own cars. :rolleyes:

Why not? I've spent thousands at a few different tuning shops all the same. When you're constantly changing your hardware you need to be able to constantly change the software as well.

Tuning a car isnt all that tough guys... its a simple task of knowing what each variable is and making the car use the best possible combination. The only difference is some tuners like to use high timing and lower boost as others like high boost with lower timing.

T.babe,

how did you come to ranging your afr through rpm? did you find something in your tuning that lead you to believe it would help?
I guess I went the other way and ranged through load.

That's going to depend on who's C16. Heck, VP has about 2 dozen race gases. But actually, most race gas is less dense than pump gas. From Sunoco's racegas site:

AKI sp.gr.
Standard Leaded 110 0.725
Supreme Leaded 112 0.715
Maximal Leaded 116 0.700
GT100 Unleaded 100 0.764
GT Plus 104 0.746

Dave