Many of my customers have been sending me emails about the NHRA decision to mandate EFI in Pro Stock starting next year.

Why throttle body injection instead of port injection which OEMs use?

Many people do not realize that throttle body injection actually produces a little more horsepower. Huh? OEMs use port injection to help with cold start and emission control. But throttle body injection wets the intake charge just like a carburetor, and that wet charge is denser, which will make a little more horsepower. OEMs trade off emissions and cold start control for that small amount of horsepower that you would never feel anyway, but Pro Stock engine builders measure horsepower by tenths of a percent.