I know a lot of you guys have superdutys and was wondering what you did for the exhaust on them?

Iknow a LOT of people just have straight pipes on them with no mufflers. I read an article in diesel power that showed the decibel difference was only 3db between straight and a banks exhaust..

I called the local muffler shop and they said they didnt have the equipment to build 4" exhaust but they'd take my muffler out and put ina 3" pipe in its place for $50..

is that 1" difference going to affect it?

i have a 4" kit with muffler now and i am thinking about going to 5 inch... you can still "hear" the backpressure when i am on stage 5 and on it.... i dumped the cat. converter too....

you definitley want to go bigger from the downpipe back and not just cut the muffler out of it.... there is alot of power hiding in there especially if you are putting a controller on it...

So you dont think it'd be worth the $50 to do this until i can afford to get a nice 5" s.s. system?

I have the SS MBRP 4" from the Turbo back on my 7.3. It heads into an MBRP muffler and the muffler splits to 4" coming out on either side behind the tires; with 5" inch MBRP tips.

I am very happy with the sound of the system. I know that a 5" system will not work on my truck as the 4" has an RCH for clearance on the transmission cross member. I have a Bully Dog 6 position chip and TrueFlow intake and the performance enchancement is awesome.

http://www.offshoreonly.com/forums/s...ighlight=power


I don't think I would want the 3" restriction in there. I think its going to be a place to build soot, and when you romp on it, the soot is going to come out in chunks. My muffler is pretty much straight through and an enhanced Y-pipe. I'd keep a muffler just encase you get any legal hassles.

you will make gains w/ the muffler removed even though it isnt the 4 or 5in pipes you want......still a move in the correct direction i would think

Remember guys you need scavanging, and some back pressure. There is no dyno difference going to a 4" VS A 3-1/2" DOWN PIPE, plus you dont have to modify the firewall. Getting rid of the Cat helps out tremendously. Going to cool duals helps a little with some small performance gain per say and 40-60 less on EGT's. My 07 will be getting a MBRP like mentioned above, in all my testing as well as all the different installations, I feel this is an excellent choice, no droan at Hwy speeds, quiet in cab but has a rumble when you kick it down, and you can always here the Turbo. JJ

I used the Bassani 4" system with a 3 1/2" downpipe and an Airaid airbox with the Edge w/attitude controller, dropped almost 200 degrees of egt under load over the stock exhaust with converter and the programmer set on #3 with low speed fueling set on #3.

do a down pipe 3.5", then a 4" exhaust system. Straight pipe will get loud when you put a tip on the exhaust system. I usually deal with mbrp and having to change distributors for my exhaust kits. Will be doing a buy in and will cut you a deal on the system if you are interested. If you are pm me and I will get the price to you.