I'm still a bit confused regarding sizes - If the stock 60mm SVT flow at 4000FPM velocity is around 96.94 CFM and the optimized 60mm SVT flow at 4000FPM velocity is around 109.17 CFM, why is a stock 65mm not as good when it will surely flow about the same as an optimised 60mm?
I just read that back to myself and it is a bit of a mouthfull - hope it makes sense