I've had a magnaflow cat-back system installed on my 2500HD for a couple of weeks now. It replaced the stock system which was a dual 3" inlet, daul 3" outlet HD Muffler, into an external Y, then into an approx. 3.75" diameter, side exit, tail section. (FYI, the HD muffler is for sale if anyone is interested, only has 1,500 miles on it) The stock system was replaced with a Magnaflow daul 3" inlet, internal Y, and a single 4" outlet muffler http://www.magnaflow.com/02product/parts/14594.jpg into a 4" side exiting tail section.
The quality of the Magnaflow system is excellent. The muffler and exhaust tip are polished stainless steel, with the remainder of the tubing being mandrel bent stainless steel.
The truck is totally stock, no HP mods what-so-ever, and it made 10-13rwhp gain throughout the entire powerband. Also, each successive dyno pull, netted higher gains, not exactly sure why though.
The 10-13rwhp figure was the most conservative gain after 7 post install dyno pulls. There is also a noticable SOTP difference, which is an added bonus

The 22" magnaflow case is a very good compromise between reasonable decibels and great performance! there is some resonance at 1900rpm, although, no where else in the operating rpm range (0-6000rpm).
For anyone considering a Cat-Back System, IMO, give Magnaflow a serious look. I'm certainly enjoying mine, and it makes real HP to boot!

 

Before:


After:








enjoy!

 

Before and after Dyno Runs. First one is the Baseline.


hhddb!

 

I'm with you! Best cat back you can buy. Was told by Southeastern Dist. that they are now selling more magnaflow product than Flowmasters. Seems like people are starting to catch on. BTW I love to hear mine sing as well....

 

Any chance you have a larger than stamp sized picture of the dyno?

Glad you like the sound, as I'm seriously thinking of using that muffler for my truck. The Magnaflow SS catback uses 2.5" pipe, which isn't exactly what I'm looking for. I'm going dual 3" but I think I'm going to take the 4" into a hard 90* bend and run it out before the rear tire.

 

thats about as big as I can get it with photobucket as a host.

 

Wow, that's some good news for Magnaflow. All I can say is, I'm damn happy with mine

 

I probably should have posted this here as well, great pic of the Cat Back!

 

Magnaflow is the way to go.. We sell Magnaflow's here at the shop that I work at. We have a website: www.engineperformancecenter.com. Check it out and I will help anyone I can with ordering a magnaflow exhaust.

 

Great post and pics. I'm planning on getting a magnaflow cat back for my new truck as soon as I have the funds.