I have a 1994 Pontiac Firebird Formula mostly stock A4 car. I have the Hooker Aerochamber muffler on my stock 2.75 in I pipe and 2.25 in. tailpipes. My question is, how much power and torque am I losing by not having the Hooker catback which has a 3 in. I pipe and 2.50 in. tailpipes? Also, would the Hooker catback be any louder than my current setup? My future plans for my car are a SLP CAI, Borla 2 3/4 Y pipe, holley airfoil, 160 thermostat, and PCM for less computer programming. How much power at the wheels do you think the computer programming would give my car.

 

Hooker cat-back has 3" aluminized piping...which flows better than stock piping depending on what you have done...