Hello,
I would like to get some idea of what the best A/F ratio would be on a 99 L :chip,pulley,fast air with stock 80mm Maf

Thanks in advance, Scott

 

i think most tuners go arounf 11.5 to 12.5 but they usually shooot for 11.8

 

12.5 is way too lean unless you are running stock timing. Most chips advance timing a little. I would say 11.5 - 11.8 or so would be fine. Anything below 12 should be okay, although you may want to run a little richer (and safer) if you are wanting to do WOT blasts in Alaska in the winter.

 

11.7 or below is where i would like to be at

 

I'm at 11.5-11.7

 

right on the money

 

Mine is in the mid 11s also but i have heard some people with 12-12.5 a/f.

 

Thanks guys

 

 

Well it also depends on how much timing you run too. I know the guys who are running a 4# w/o chip are seeing AFRs in the low 12s, but since there is no timing advance from a chip, it is considered pretty safe.

 

Timing or no Timing, i dont see how a 12.0 - 12.5 is safe. Lean is lean and thats all there is to it.

 

I have seen info from two different people on this board (can't remember who) that have dynoed thier trucks before any modifications and were running 12-12.5 at the tailpipes, which coincidentally is exactly what I am running with my 4#er/no chip. No pinging or any other issues here, even when pulling my 3000# boat. Sounds safe to me.

 

My race program for 94 octane was at 12.1 A/F........20* timing.

I never had any detonation........even racing in 30* air.

--Joe

 

Best ratio is good old 14.7:1

Of course never going above that is the real trick, so just like everyone else said, 12 or richer is good.

 

14.7 is the magical but impracticle level. I will not comment on what is to lean or to rich.....everyone has their own opinions. Most people would dis me for being lean, but, I've got almost 20,000 miles and w/no problems; lots of power for my mods; and my plugs have always looked beautiful.