I know there is no magic number and that you have to give the motor what it wants
but I am looking to see if there is a general average.. For all you guys who have dynoed or track tuned your car for the most horse power and torque, what air to fuel ratio gave your the best numbers... I did mine today ..92 L98 with no internal modes..and gained 16 hp and 38 ft lbs by changing a portion that was 12 to 1 and made it 13 to 1 but was wondering if maybe I should keep leaning to appox. 13.5 to 1.. any input guys.

 

I can't believe 36 people have read this
and no one has a reply.. anyone!

 

My motor likes around 13:1. General knowledge says to use around 12.7:1.

My opinion is to use the richest mixture that you can so long as that mixture doesn't rob significant horsepower. For example, if 13:1 makes 350hp and 12.7:1 makes 348hp ... and the torque curves are nearly identical then run the richer mixture to be on the safe side of things. However, if there was a major horsepower difference between the 2 (closer to 10) then I would go with the leaner mixture.

... of course, I am speaking from a performance standpoint with regard to having a lot of power. If you don't race much and your car is a daily driver then always run the richer mixture and keep the A/F to UNDER 13:1.

Tim

 

Good gain!
AFR has told me that alot of times you will find max power close to 14.0:1 But that is pretty risky.
Like you said , give the engine what it wants and watch knock .
My WB broke a year ago, since I have just been tuning WOT at the track and seeing how the car responds.
And like Trax said if you can run the same time @ 12.8 as you do 13.5 - go for the 12.8.
But if the car is responding slowely go for it.

 

Thanks for the input..I guess I won't go any leaner then.