I've been thinking lately how I want to quiet my truck down, thought about sound mat but I've seen alot of reviews that some say it doesnt do very much, so I had an idea that came to mind. When I go boosted which it will be very soon, with the on3 kit you run the drivers side stock manifold and then their log for the turbo, I belive theres comes with a 3 in downpipe.

I want to have a custom 4 inch down pipe made and put a electric cutout on it then after the cutout drop the pipe back down to stock size and run a stock muffler for sound and to somewhat be a sleeper setup. I like the way my truck sounds now, honeslty just getting tired of it on long highway trips is the reasoning I want to do this. Truck setup now is a RCSB 5.3 (cammed, heads) with longtubes, y-pipe, full 3 inch exhaust into a Borla xr-1 running all the way out the back.

Any input on this, and will it really make a difference in the cab running it like this, I'm just not sure how loud a turbo manifold compared to long tubes, so any turbo guys feel free to chime in.

Thanks - Kyle

 

Adding a big resonator to the exhaust right now would make it quiet and better on your ears. I bought a vibrant ultra quiet res when I was catless on my 06 Sierra, it took all the rasp and drone away. Installed it before the muffler.


But I do think the turbo will help muffle some of the sound, it won't be like the long tubes. Likely still be somewhat loud but adding that resonator should take care of alot of the unwanted sounds.

 

I have put almost 5000 miles on my RCSB truck with a kbracing set up. I still haven't put any exhaust on it so it's just the 3 inch dp right under the passenger's feet. If the heat shields hadn't vibrated in half under the truck it wouldn't sound too bad. Plenty loud when you get all over it though. I think I will just get it out from under the cab, point it at the road, and leave it. If you're going for sleeper, these things are surprisingly quiet at idle and even at regular cruising RPM. Personally, I think using the stock muffler would be waaaay overkill for the sound, not to mention, really restrict your flow.

 

Thats the only thing I was really worried about, I know the stock muffler would resrtict it pretty bad, so I would only run it with an open cutout, Stock muffler would mostly just be for cruising in town not getting on it, or highway driving

 

Turbos quiet down the exhaust a lot more than you think...cutouts are fun though