I have a diamond-eye system which I have yet to put on. The guy that runs the muffler shop tells me that running a flowmaster muffler with my stock exhaust will accomplish the same thing as putting on an entire system. Can anyone comment? I need to decide ASAP b/c I have an appointment on Friday to install.Edited by: 2thdr

I'm fond of the OEM system, but the OEM muffler is heavy and relatively restrictive. There are some good aftermarket exhausts out there, so replacing the OEM muffler with a good muffler could lower EGTs and add some sound, if that's what you want. I've heard of the diamond-eye for the straight-guy system, but that's about it. http://www.dieselplace.com/forum/smileys/Approve.gif


Is Flowmaster better than Magnaflow?


Edited by: Ray403Dmax

slow night? What I'm wanting to find out is will the muffler itself lower EGT's as well as a 4" system? Is the flowmaster loud? As in louder than a strait pipe? Who has a flowmaster? Who loves it? Who hates it? So many ?'s. One more. Is anybody out there?

A few comments...


More specific questions get better responses.


This topic has been beat to death, try a few searches here and at other sites.


Don't take it personal.http://www.dieselplace.com/forum/smileys/Wink.gif

Does it lower EGT = Yes - Under load it made a big difference. Arouind 2-300.


Is it loud..? - Well it was to start with but seems to have settled down. Haven't been in one with a straight pipe but my buddy has a Banks with no cat and the banks is a lot louder.


Who has the flowmaster? Me :) , Mike Tomac too.

I installed a flo master part number 53553. It is not a straight thru;but it gives a nice mellow sound. It evidently does not even get hot because it has not even changed colors. I am not running a performance box, not a hot-rodder but I really think it gave a little better throttle response. I cut the oem muffler as close to the inlet and outlet as possible; it fit right in place. I do often tow a 30 ft tag a-long, mostly mountain trips and I think it is pushing the air a little better. Also I am using a K&N air filter which I think helps a little too.

If you already have the exhaust, I would have it put on. Changing the muffler isnt going to give you as much of a gain as going to a full 4" system. Thats my opinion.

Make sure you get Flowmaster part #953553 (28" long) NOT part #953558 (25" long) that Flowmaster claims is the replacement muffler for the Duramax, it's too short. Edited by: mtomac

mtomac, It's too late I already had a 953558 installed. I hope it will still function properly. Every post I've ever read gave the same part #. When did it change?

I'm not sure why Flowmaster lists the 953558 as the replacement muffler for the Duramax on their website when the 953553 is the one that is closest in length to the stock muffler.

I've put about 200 mi on since installing flowmaster sounds really nice. It does drone pretty significantly between 55 and 60 mph. It's a good thing I never drive that slow. http://www.dieselplace.com/forum/smileys/Big Smile.gif Does the exhaust note change with use?

Mine seemed to improve as soot got in it.. Didn't like for the first week or so and then it got better.

2thdr & blowingsmoke,
Which part number did you install? I want to avoid any drone, and if you have noticeable drone, then the FLO is defiantely out for me. I'm leaning towards Banks anyways, but I'm not 100% positive yet.

I guess I will let you guys do the homework on this. I want something different as well but not sure what. Hope you keep this going so it will help some other people get a better idea on where to turn. Right now I can't justify a complete system, but might do the muffler.

2thdr: I noticed in your signature you have the Attitude. How much of an EGT drop did you see?

Straight piped is just right.....unless you tow heavy alot. It barks pretty good with a load, otherwise I think it sounds great. Deep and throaty.


http://pic8.picturetrail.com/VOL227/437876/777914/29342776.jpg

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