im lookin in to buying the monoblade billet throttle valve it has 1300 CFM airflow and instead of having two butterfiles it has a full circle and my question is that my car is getting perfect air and fuel mixture but if i change to this one will it start running to lean?

 

Your A/F ratio is controlled by the PCM, based on feedback from the O2 sensors. What year is your car? Most likely is a 94 or newer and runs with an MAF sensor. The MAF sensor measures the actual air flow, the PCM adds fuel based on the target A/F ratio, and the O(2 feedback is used to make corrections in the A/F ratio to get it correct. Has very little to do with the size of the throttle body, unless its too small.

What modifications do you have done that make you feel you need a throttle body rated at 1300 CFM? Just because the TB is capable of flowing that amount of air at some given pressure loss (you haven't stated the way it was measured, in terms of pressure loss), doesn't mean it will flow that much air on your engine. If your engine only needs 500 CFM (e.g. - 383 stroker at high RPM), thats all it is going to flow, no matter how large you make the throttle body. You can make 500HP NA at the flywheel with a 52mm TB.