There is no evidence that specifically shows that certain amounts of back pressure is required to make an engine run properly. Back pressure is bad for any engine due to the fact that the engine has to fight to get rid of the exhaust thus hindering the performance. It is more about the pulse of the exhaust gases leaving the engine through the tubing. With each cycle of the plug firing and the valves opening to release the exhaust there is a lack of hot exhaust gas in the tubing and the hot air has to push the dense air through. Hot air is good, thus you need to have the right size exhaust to maintain that heat and get it out as fast as you can.

 

we are using that term very loosely here...but it's hard to explain efficient scavenging (that's what we are meaning with backpressure) without trying to use the simplest words possible..

 

if you do it, dont put a DodgeForum sticker on your truck and if you have one take it off

 

LOL, awesome...