Ok.....so i was running one straight pipe on my mustang with a 351C......and now im running two and its so terrible now.......there is none of the torque that was there anymore......im assuming because of the lack of backpressure.??......someone explain this to me please????? how do some cars run open headers and still have all that torque?....

stock cam? Your car is relying on a stock system to create intake velociy. All that free flow is killing you. If you want a performance vehicle, go all the way and do it up! Putting a wide open exhaust on a stock motor is pointless-

K