Tuned on Greddy Emanage by GILES MY04 runs pretty safe AFRs so far, in fact they are between 10.8 and 11.6 at WOT. I was wondering if I would hurt my tune in any ways and possibly even lose power by just simply slapping on a bigger ScienceOfSpeed throttle body that claims 12HP?


know everything was tuned so it's safe yet it makes the most power, so by adding more air my AFR will go up slightly and skew the tune, but will that mean I lost power OR not really gain any without a re-tune.... Please advise.

 

It will just lean it out a little, those AFR's are on the safe side as it is. You could run the AFR to mid 12's and not lose power - i do in midrange (about 12.3), however at that level you'd want to look at the timing. It might made somepoints leaner than others, but i say to add it and watch your AFR's.

 

Your running too rich really. That TB will gain you about a full point in your afr and you will gain power, but ideally your going to need to add a little more fuel again to be safe if your tuner set you that rich for detonation reasons. But ideally 11.8 -12.5 is a good afr target so that would put you there.

Of course this amount of afr leaning is on the assumption that you port match your manifold opening as well to see the full benefits.