That might be the better question. Since it seems that few have actually put a P-70 in a bypass, what is the recommended bypass dia.? These were sold to me as P-70 size but they do seem a bit small. Normally you would want the exhaust approx. 5/8" in front of the bellmouth. In a bypass situation, the 'front' af the bellmouth becomes rather vague. Even with a Funsonic in the same duct, you gain a great deal of room, but the exhaust is even further from the 'front' of the bellmouth.

Thanks for responding.

DC