I installed a silent might muffler today and it's a little to loud in the cab for me.. If it doen't gain any mpg I'll be going back stock..

Rob

 

Any further impressions after living with you Rokk muffler.

 

I went back to the stock muffler. There was mabe a 1/2 mile per gallon gain in fuel milage but wasn't worth the noise to me.

Rob

 

I was thinking of getting one of these and I was surprised to hear about the noise problem. Does anyone else have similar experience with noise.

 

why not run a 51" big truck muffler?

some sound deadener and or a resonator probably would have made the silent might work out better for you.

but really, just run a bigger muffler if you want better flow w/ less noise. I'm still not buying the hype. I don't see how you can "tune" a piece of perforated steel to somehow pull exhaust at a certain RPM range

 

I had the 51" Nelson in the 03, and was very happy with it. No drone when towing, and a nice mellow tone(not loud). I have the 40" Nelson in the 05 with Cat, and am happy with it. Turbo whistle is more noticeable, not loud at all, until you really step on it. Haven't towed yet, but it doesn't drone now when you step into it up hills, etc.

 

Who makes one of those 51" mufflers you speak of? How much are they?

 

Nelson. I bought it at Cummins for about $90 I think. The 40" was about $65. They are a 4"in, 4" out straight through muffler. The 51" is 10" diameter, and I think the 40" is a couple inches less in diameter, but a good match up with the Cat. If you want quiet, combine the 51" with the cat, and you shouldn't notice any difference from stock. (A bit tight with the cat and 51" on a SB).

 

I bought the Rokk muffler because I tried a few others and they were too loud for me. The Rokk muffler is quiet- No one has been able to tell that I have a performance muffler... Did you leave the cat in place? (I did) Did you install it with the baffles at the inlet? Exhaust leaks?

 

Has anyone seen the 5" Rokk muffler? I emailed them about it and never heard back.

 

Nelson M090535 muffler 51" long / 9" round 5" inlet and outlet straight through muffler. Ryder Fleet Products $67.99.
http://www.ryderfleetproducts.com/cg...m.0&oid=128022

 

I have a Silent Might muffler installed with cat and its not that much louder than stock. When I accelerate you can heir it though. It doesn't drone. I have not had the chance to pull my fifth wheel to see what it sounds like under a load. Over all I am satisfied with it so far.

 

I e-mailed them also but no answer. I am going to order the muffler in the post above for my 5" exhaust. LooseboltsRob has one installed and loves it.

Shane

 

That sounds about right for the 4" -51" Nelson as well(it's been awhile since I bought it!)