Thread:Gunner5795gt/@comment-3019062-20130129082154/@comment-4850381-20130401080733

Same here on the late reply

On car warranties, intake and exhaust mods usually dont void warranties. A staight pipe exhaust (usually without the cat) will increase horsepower but reduce torque because it reduces the backpressure generated from an exhaust that doesn't flow as well as a straight pipe exhaust or a high performance exhaust. Backperssure generates torque but decreases horsepower. A high performance exhaust with still have the cat but the flow of exhaust isn't as good as a straight pipe but its still street legal and its better then stock exhaust. Straight pipe exhaust isn't street legal and its only legal for racing applications in all countries plus it voids warranties.

A cat(a nickname for catalytic converter) is a emission device use to limit how much toxic gas goes into the air. It restricts some flow of the exhaust and its required in all countries for your vechile. When there's more flow of exhaust exiting, there wil be sharper & louder tune for the exhaust.

What the boy racer probably did what increased the diameter of the exhaust to increase the flow to produce louder sounds. It isn't going to increase the horsepower dramatically but probably around 5-15 horsepower at max, isn't gonna make much difference in a racing.

Another way to produce louder and sharper exhaust tune is to increase the redline rpm of the engine. Most people won't increase but some tuners will because the higher rpm engines would break down easier then a lower rpm engines. Im not a fan of american push-rod v8 engines but there very reliable becuase they have lower rpms and less moving parts from there DOHC v8 counterparts. Push-rod engines are designed to generate more torque because there pistons are taller then the ones found in DOHC engines. Lower rpms means better mpg, thats partially how corvettes get good milage.

The more power your engine makes, the more stress its gonna put on the transmission and chasis. The more stress on a car part, the easier its gonna break.