On a Sunday morning on TNN was a show about exhaust. They were talking about the more you free up the rate of flow the more horsepower you are going to gain. They were talking about This is why race cars use a straight through exhaust. Can't remember the name of the show though. I have heard from many sources though that you do need the backpressure to keep the torque. I have not dynoed my car to prove this, but i did take off the exhaust system to see with so much free flow would actually do. I did see a noticable difference in low end torque loss but I did feel an increase in top end horsepower. I dont have any proof though, but I thought I would share what I have noticed and heard about in this area.
