What's the best A/F on a dyno?
 

I have seen this mentioned before, but can't find it now. What is the best A/F for max performance when measured on a dyno, not on the street. I believe there is a value at max torque and at max horsepower.

Re: What's the best A/F on a dyno?
 

You should shoot for a 13:1 A/F. I've heard though that you go 12.8:1 because on the track it actually runs a little leaner. Mine's at 13:1 and makes max hp. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Re: What's the best A/F on a dyno?
 

Other way around. 12.8:1 would be richer. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

12.8 parts of air to one part fuel.

Anywhere between 12.8 - 13.1 is optimum. I say that window cause each cars is slightly different.

Re: What's the best A/F on a dyno?
 

On a Dynojet...

I'd say:

12:1 AF for forced induction
12:1 - 12.5 for stroker
12.5-12.8:1 for stock cube NA

Re: What's the best A/F on a dyno?
 

My understanding is for a NA car:
12.5-12.8 near peak torque
13.1 near peak hp

Tommy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Re: What's the best A/F on a dyno?
 

OK, for calculation purposes, let's ASSUME that 12.8 is for max torque and 13.1 is for max HP. Should the fuel curve at WOT be mostly at 13.1 and dip to 12.8 at max torque rpm, or be at 12.8 and rise to 13.1 at max hp? Or maybe run somewhere in between?

Re: What's the best A/F on a dyno?
 

each of our cars likes things a little diffent, mostly becasue of air quality, +/- sea level
etc. BUT you are right on for the base line. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Re: What's the best A/F on a dyno?
 

At 13.2:1 I made 4 more ft/lbs of torque than I did at 13:1 HP stayed the same.