has anyone done any testing to determine the optimal AFR ratio for f22's and more importantly is willing to share....

no rules of thumb please. thanks.

 

On my H22 with bolt on's, I was running,

WOT 13.0
part throttle 14.7
cruising 16.0

And that was with DSM 450's. Not bad for injectors that were designed 2 decades ago. Curios as to how this will compare to an F20/22 with OEM injectors.

 

I've tested the whole range of AFR's in my DBW F22, and it seems to make pretty close to the same power anywhere from 12 to 14. I think best is about 12.5 using the stock primary O2 reading (wideband).

 

12.5 is very rich I was thinking more along the lines of 13.4....

Did you see this ideal afr vary with rpms?

 

Rich and lean are relative terms, so it's true that 12.5 is richer than 13.4. However, many people consider 12.5 to be ideal for peak power. The only reason why I would go leaner than 12.5 would be if I was using a piggy back that uses MAP manipulation to tune. In that case, I would consider going much leaner, since that's the only way to advance timing.

 

BTW, I haven't noticed any fluctuation in ideal AFR's based on RPM. When I overlay different torque curves from other calibrations I've tried, the only thing that seems to change the shape of the torque curve seems to be VTEC engagement and ignition timing. However, with a piggy back, that would be totally different, since timing and fuel are linked by MAP. You might find that best power with a VAFC would come from a wildly fluctuating AFR.

 

for most NA honda's 13.3-13.5:1 will give you the best power, you will see increasing power loss once you get richer than 13:1.

for cruise, these things dont care.. 14-17:1 works.. part throttle acceleration will see a big hit as far as economy goes if you are richer than 14:1 and crappy response leaner than 15:1

 

I guess I should add that the 12.5 I'm talking about is from the OEM wideband, which Hondata says reads richer than it really is. The "AF Corr" value is about 13.5, but I don't believe it is nearly that lean. My aftermarket wideband reports richer than the AF Corr value, but I haven't installed it since I tuned it richer. I guess I need to do that again soon.

 

To give you an idea of another honda motor.

the k20z3 in my civic liked 12.6 afr way more than 13.0 afr. I picked up a solid 5 horsepower from richening up.

 

Everyone has there ideal ratio, but all cars are different as a rule I run Honda's at 13.1 N/A, well i dont run them any leaner.

Typically 12.7 - 13.1