Ok, so I busted out the sawzall and cut my cat and muffler out. replaced it with 3" pipe to match the factory turbo pipe. It exits right before the pass. side rear tire, angled back and downward. It doesn't sound quite how I thought it would but that turbo really sings !! It sounds like a Tandem dumptruck...

 

Cool, but i bet you get tired of your wheel being black.......

It may not sound like you expected because the exhaust is exiting so close to the cab, it makes it considerably louder.

 

I don't care about the wheel...It's not a looker...It's a snowplow truck and is for go no sho.. It has some kind of weird hollow sound only at idle... the loudness is not it....give it some throttle and it sounds mean....

 

if you want better sound even at idle run a 4" or even 5" straight. i have 5" on mine cant beat the sound.

 

I just put a 5 inch MBRP and it sounds alot like 3 inch, only considerably louder. i set off lots of car alarms now. too many some people might say lol. its a nice loud though

 

Is your 5" louder than a 3" strait pipe in you cab? I'm looking into a 4" or 5" strait pipe.

 

When I bought my truck it had a hollowed out cat, and the muffler was replaced with straight pipe. It was pretty loud, but sounded good... although it was a bit raspy. I have since replaced it with a 4" system (from Summit Racing)... it's quieter at idle, and sounds even nicer without the rasp!

 

4" from the bottom of the DP to a full exhaust sounds great. It's deeper than the stock pipe straight, and got rid of the raspyness that was annoying me.