Last time at the dyno, I was running rich, 12.5-12.1 from 4500 rpm+

I'm adding 1.6 RR's this spring and was wondering if it will change my A/F ratio at WOT.

I was thinking that since they help the engine breath, that they might raise the A/F ratio and get me close to 13.1 Or will the PCM compensate for the extra breathing and keep my current A/F at WOT.

Any thoughts on this?

Thanks,
Dan

 

The PCM reads the air flow via the MAF sensor, and adds the required fuel. If your 1.6 RR's increased air flow, the PCM would see it an add the extra fuel, using the same "target" A/F ratio that it was programmed for. Shouldn't change what you see on the dyno with a wideband.

 

Thanks Fred. I was hoping that you would chime in. Looks like I'll make another dyno run this spring with the new valvetrain(assuming that there is another dyno day)

I'll see where my A/F is, and send the PCM to Ion to get tweaked again.

Dan