What is the optimal AFR for torque and what is optimal for HP? I have seen this info posted before but I cannot find it. The weather is starting to warm up a bit and I'm about to start working on my tune again. I have driveability decent and want to start working more on WOT.

 

Richer for max torque - 12.5 to 12.8, leaner for max hp - 13.1 to 13.4. I saw an excellent chart on this too but I too can't remember where, if I think of it I'll post up.

 

Isn't the point of calibration to obtain max torque everywhere - giving max hp everywhere????

 

Yes.


He's probably referring to setting one AFR at the rpm range of max torque produced on a dyno, and setting a different AFR at the rpm range of max hp.

Some folks like to run richer in the range of peak cylinder pressure to help prevent detonation there. While letting it lean back out as the pressure/torque drops back off when the engine becomes less efficient at the higher rpms, which helps to broaden the torque curve, and extends the HP curve a bit longer.

Can be done with timing, afr, or combination of the two. Hard to pin it down exactly without running on a load controlled dyno though.

 

That's basically what I am after. I'm not planning on any dyno time at the moment though. I'm going to try to get it close on the street and then take it to the track in a few weeks to do some fine tuning if I can find the time.

Thanks for the replies

 

Interesting. So some people have it rich near peak torque and then as torque begins to drop they lean it out a little? Interesting concept