Okay i have a 80 series flowmaster but ive heard that since its a chamber muffler that its not a good horesepower gain using a chambered muffler.Is that true also i was looking at the stock y pipe and its a BIG JOKE no smouth flow at all so would i gain any horse power by buying the hedman y pipe?

 

plenty of chambered mufflers flow well. the 80 series crossflow design hurts its flow. getting a better y-pipe would help.