Added Flowmaster

[Greg McCall]

I had a Muffler Shop add the Flowmaster muffler made for the Duramax. Was easy to add and they saved the original Muffler for me. The shop did have to add a short section of 3.5" extra pipe.
You would have thought Flowmaster would have made the Muffler longer.

Sounds deeper and has just a slight bit of drone around 2000 rpm when I pulled my car hauler and car around, but otherwise you would hardly know the sound from stock. The sound ,or lack of, is what I was hoping for.
No performance tests.

[mtomac]

What is the part # of the Flowmaster muffler you had installed?

Did they cut pipe off as close to the stock muffler as possible?

The replacement Flowmaster muffler for the Duramax is part #953558.

[Greg McCall]

Michael,
The Stock number you list was the Number on my box. I took the number from the Flowmaster website to the Muffler Shop, to make sure the correct part was ordered.
As for length, I personally walked under the truck at the shop to compare lengths. New muffler was going to be an inch or so short if they left all tail pipe they could and cut as close to the old muffler as possible. That would leave me no pipe on the old muffler for me to reuse it(if I choose to latter).

[Phil B.]

Greg - Do you have a pyro? It will be interesting to see if the the muffler replacement makes much of a difference in EGTs. What was the seat of the pants feel as far as performance. Just think you can still gain an additional 25 ft/lb of torque when you install the Dynomax "turbo down tube."... :mad:

[Greg McCall]

Phil B,
I have not installed guages yet although I am thinking on doing so. I seldom tow and only about 6000 lbs when I do.
I haven't felt much of a seat of the pants improvement, but then I haven't run it hard. I run around on Level 3 Juice and may switch to Level 4 with Tow Haul " should the situation call for even more power" :D No such "situation" but I'm looking.

[ 09-09-2003, 10:09 AM: Message edited by: Greg McCall ]

[mtomac]

I think the flowmaster is a good balance between a straight pipe and the stock exhaust

[Phil B.]

Also sounds like an affordable "trial & error" to see if I can stand the sound while towing. I want to do everything practical to lower EGTs but don't want to put up with a loud drone for hours on end (been there done that with gassers).


Phil B.

[mtomac]

Make sure you get Flowmaster part #953553 (28" long) NOT part #953558 (25" long) that Flowmaster lists as the replacement muffler for the Duramax, it's too short.