Two days ago I removed the muffler from my exhaust and replaced in with 4" stainless which exits behind the back door. Other than the whistling noise im assuming comes from the turbo I am pleased with the results. Does this bother anyone else? I think im going to install a muffler to take care of the whistling. Need some suggestions. I need something that will fit onto the 4 inch ID pipe and something fairly inexpensive, ive already spent more than I wanted to on the exhaust. Will I loose much of the gained power by adding a performance muffler?

Thanks
Steve

 

i bought a 4" kit (turbo back) and it had a muffler. I have replaced it with straight pipe and plan to keep it a straight pipe exhaust. In otherwords, i have a new 4" muffler that im not using...
If you dont want to mess with muffler, make it exit behind the rear wheels. I tried to make my exhaust exit in front of wheels, and it was a bit louder in the cab. But once i did it the way i really wanted it, (straight pipe turbo back exiting behind wheel) it is no louder in the cab then the exhaust with the 4" muffler.
On the outside however, is a very different story

 

The whistle you hear is the turbo spooling up quicker because the exhaust is less restrictive. If you add a muffler, purchase a high flow performance type you should not lose any hp. Some people run their exhaust straight piped like you have. Depends on your preference.

 

I've had my exhaust set up every possible way. I've had a stock system without a muffler, a 4" system without a muffler, a 4" straight pipe, and back to a 4" system with a muffler. Maybe I'm just getting old, but the fluttering sound gets old after a while. You don't hear it as badly with a muffler on, so I always go back to adding a muffler. If the muffler you use is a straight through design, you likely won't lose enough hp to even notice.

 

I remember a thread, where if you want to get rid of the flutter have the tip point down to the road instead of parrallel to it.