My dad just bought a used polaris sport. My question is, What is the quietest best performing pipe available? He was going to get the HPD, but he doesn't like the notion that you have to get a clutch kit. How's the Dynoport pipe, is it loud?

Any help would be great.

Get the HPD pipe and use your stock HPD silencer
works good and not very loud.
also get the clutch kit to match the pipe.

Get an HPD pipe, and either use your stock silencer, or get the forestry approved HPD silencer, it's a lot quieter than most (except your stocker). The clutch kit is well worth the $80 asking price. Also put in a Uni-Filter.

All pipes need a clutch kit, The power band changes with the pipe which runs at a different rpm than the stocker, When I talked to Dynoport they also had a clutch kit they recommended me, Thats why I went with HPD and got there pipe and aggresive clutch kit at $140. The money is well spent and he wont be disapointed, He might as well save some time and get both at once because you will end up doing both it the long run for maxium performance from his pipe, If not he will probably just make his Sport louder and slower:)