North_of_55

Hello All,

I am looking to replace the MBRP muffler (cracking in 3 locations) in my 4" turbo back system with the 40" Donaldson.

Does anyone have any tips (based on their experience).

I'm assuming it will have to be mounted ahead of the existing forward muffler hanger location (replacing the existing muffler with a piece of pipe). Will it make any noise/performance difference to mount the muffler further forward in the system?

If anyone has any pics of their install I'd appreciate seeing them!

Thanks,

Dave

tige hauler

I would strait pipe it as you will probably not notice to much of a difference being that the MBRP is a strait through design. maybe 1-2 decibles but the tone will be much nicer. And you wont have to worry about it ever again.

North_of_55

I know it sounds crazy but I actually want my truck to be quieter. That's why I'm looking to go with the Donaldson 40".

I was just wondering how/where others had installed them.

To be honest... the exhaust noise doesn't bother me too much. But the combination of noise up front and the exhaust is a little too much. I haven't found a suitable way to kill the noise at the source (ATP quiet kit is about $1000 more than I'd spend on noise redustion).

I guess I'll just get the muffler and see where I can stuff it in!

Midnite

You might talk with Rip Rook at Source Automotive ( http://www.sourceautomotive.biz ). They started out doing custom exhausts, and I've heard people claim he can make a 4" exhaust system that's quieter than stock.

I've dealt with Rip on on other things, and his company is absolutely first rate.

tige hauler

if you remove the muffler the engine noise will actually subside a bit. Also I removed the muffler section from a 97 powerstroke and it actually was quieter according to the decible meter by 3 decibles. Believe it or not back pressure can actually make an exhaust noisier.

DanMan

On the '91.5 I had, I first had the muffler removed on the stock exhaust. It sounded really cool but had a drone at very low speeds and at load on the highway. I then put on a Stan's Headers 4" turbo back exhaust with the Donaldson straight-through muffler and it sounded nice, without the resonance or restriction of a typical muffler.