why does a performance exhaust system increases power?
It lets the engine breathe better thus creating more power.
Reduced restrictions from cost-based parts developed for the exhasut from the factory. and when combined with aftermaket modifications yuo help the engine breath (and exhale) more efficently
new limitations to reduce emissions(which DO NOT ACTUALLY AFFECT GLOBAL WARMING OR THE OZONE LAYER) make thier mufflers small and restrict air make them soft. a performance exhaust takes out all those limitations and makes the car exhale more easily so it can inhale more air faster/better. plus if done properly it makes the car sound good.
