Installed magnaflow on 6.0l yesterday!!!

Coachmenguy · March 19, 2006

well i finally got my magnaflow muffler and my 4.5" tip installed on my '03 2500LD and it sounds awsome!!!!! almost stock going down the highway, and nice rumble tone when you get on it!!!!!!!!

I ran into a slight hassle when i started to call around to local muffler shops because the muffler made for the 6.0l part #(12595) has a 3.5" outlet, so i ordered a tip with a 3.5" inlet, thinking a 3.5 inch pipe from the muffler to the tip would be no big deal, but EVERYONE only can bend pipe up to 3" so i had to go with just that, 3", its ok though and its more than enough, between the muffler, tip, and installation, it cost me $300, so far so good!!!

has any one else put exhaust on their 6.0???

djv72 · March 20, 2006

well i finally got my magnaflow muffler and my 4.5" tip installed on my '03 2500LD and it sounds awsome!!!!! almost stock going down the highway, and nice rumble tone when you get on it!!!!!!!!
I ran into a slight hassle when i started to call around to local muffler shops because the muffler made for the 6.0l part #(12595) has a 3.5" outlet, so i ordered a tip with a 3.5" inlet, thinking a 3.5 inch pipe from the muffler to the tip would be no big deal, but EVERYONE only can bend pipe up to 3" so i had to go with just that, 3", its ok though and its more than enough, between the muffler, tip, and installation, it cost me $300, so far so good!!!

has any one else put exhaust on their 6.0???

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I have an 05 1500HD Crew Cab and I am looking at putting the Magnaflow cat back system on my truck. The system has a 22" muffler. My stock exhaust is 2- 2 1/2" in and 1- 2 1/2 out. I pull a 16' enclosed trailer so, I don't want to much noise inside the cab.

I am worried about going from a 2 1/2" tailpipe to a 4" tailpipe. Do you think I will have any problems with that?

I had an 03 Silverado with a 4.8 and I put a 40 series flowmaster on that truck. Boy, talk about noise inside the cab!!!!!

Thanks, Dan

GM-Mike · March 20, 2006

I just had the 12599 put on my 2001 6.0L LT 2500hd and I almost love it. A little drone @ 1700-1800 rpm in the cab but, other than that perfect low throaty sound for me. $170 total, $60 for the install and $110 for the muffler. 12599 is a dual 3" in and dual 3" out. My tailpipe is a short 3" Y that turns into a single 4" tailpipe. I installed an Innovate wide band 02 w/gauge this weekend, HPTuners on the way, headers next, gotta love it.

djv72, I don't really have anything to compare to.

Coachmenguy · March 21, 2006

hey GM-Mike, where did you find a 4' pipe??? here in michigan nobody would bend pipe over 3"!! not even a diesel shop!! is that 4" just your tip??

djv72 · March 21, 2006

I just had the 12599 put on my 2001 6.0L LT 2500hd and I almost love it. A little drone @ 1700-1800 rpm in the cab but, other than that perfect low throaty sound for me. $170 total, $60 for the install and $110 for the muffler. 12599 is a dual 3" in and dual 3" out. My tailpipe is a short 3" Y that turns into a single 4" tailpipe. I installed an Innovate wide band 02 w/gauge this weekend, HPTuners on the way, headers next, gotta love it.

djv72, I don't really have anything to compare to.

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GM-Mike, when you are driving 55-65MPH is there any type of drone? I have a 3.73 rear-end in my truck but, I'm not at 1700-1800 rpm's very often. I'm right around 2100-2300 rpm's on the interstate.

I think I am going to order the magnaflow cat-back next week, I'll keep you posted.

Thanks,

Dan

catiaeng · March 21, 2006

Welcome to the Magnaflow club Coachmenguy. I've had mine for over a year and LOVE the sound!

BJ

03HD · March 21, 2006

I put a #12469 on my 6.0 (dual 3" in, dual 3" out) used my stock 3.5" tailpipe and welded on a 5" magnaflow tip with a 4" diameter intake (#35120). The exhaust shop welded on a small piece of 4" pipe to the 3.5" pipe and then welded the tip on the 4" piece. Check my post install link:

http://www.gm-trucks.com/forums/index.php?showtopic=46389

GM-Mike · March 22, 2006

hey GM-Mike, where did you find a 4' pipe??? here in michigan nobody would bend pipe over 3"!! not even a diesel shop!! is that 4" just your tip??

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Maybe a foot of 3" Y at the back of the muffler the rest of the tailpipe I'm pretty sure is 4" could be 3.5". I'll check today.

GM-Mike · March 22, 2006

I just had the 12599 put on my 2001 6.0L LT 2500hd and I almost love it. A little drone @ 1700-1800 rpm in the cab but, other than that perfect low throaty sound for me. $170 total, $60 for the install and $110 for the muffler. 12599 is a dual 3" in and dual 3" out. My tailpipe is a short 3" Y that turns into a single 4" tailpipe. I installed an Innovate wide band 02 w/gauge this weekend, HPTuners on the way, headers next, gotta love it.

djv72, I don't really have anything to compare to.

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GM-Mike, when you are driving 55-65MPH is there any type of drone? I have a 3.73 rear-end in my truck but, I'm not at 1700-1800 rpm's very often. I'm right around 2100-2300 rpm's on the interstate.

I think I am going to order the magnaflow cat-back next week, I'll keep you posted.

Thanks,

Dan

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On my setup the drone is at 1700-1800rpm. Come to think of it, I don't think I've been on the highway since the install. I'll try it and let you know. I was wondering if you could put a tip on or put a dent here or there to try and change the frequency at which the truck resonates (drones).

GM-Mike · March 22, 2006

I put a #12469 on my 6.0 (dual 3" in, dual 3" out) used my stock 3.5" tailpipe and welded on a 5" magnaflow tip with a 4" diameter intake (#35120). The exhaust shop welded on a small piece of 4" pipe to the 3.5" pipe and then welded the tip on the 4" piece. Check my post install link:

http://www.gm-trucks.com/forums/index.php?showtopic=46389

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Sounds nice! I thought about the shorter one but, I was afraid it might be too loud when I get the headers and HiFlo cats installed. I do smile more lately

White Knight · March 29, 2006

Congrats on the new system. Have you seen any mpg increase? I am sure you have a good seat of the pants increase. Post some pics I would love to see what it looks like on your rig.

Coachmenguy · March 29, 2006

Congrats on the new system. Have you seen any mpg increase? I am sure you have a good seat of the pants increase. Post some pics I would love to see what it looks like on your rig.

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this weekend is supposed to be nice so i want to wash/wax it up and get some new pics now that spring is here, so i'll have pics in a week or so!!!

motobw · March 31, 2006

I also just purchased a full magnaflow cat back for my '03 1500 hd today. I figured I should just buy the stainless system (part # 15782)that will last longer than go to the local muffler shop and have to buy their Aluminized fabricated set up that was going to cost close to the same. I guess because of the 6.0 Liter dual in single out stock muffler the muffler shop didn't have any thing like that in stock so he suggested mounting two mufflers side by side and custom bending the pipes straight out the back and each muffler costing 150 each. Magnaflow system is costing 471.82 shipped to my house, I'll post again after install.

johns454 · April 30, 2006

I just installed Magnaflow #15789 3" dual in 4" single out. Sounds great, much better sound than my 5.3 with a 50 series flow. I'm converted

jbracefan1977 · March 19, 2009

I just installed Magnaflow #15789 3" dual in 4" single out. Sounds great, much better sound than my 5.3 with a 50 series flow. I'm converted

Hey johns454! I am another recent convert too. I have the magnaflow 15789 just installed and love it, they are cheaper on ebay but I wanted a warranty (the salt on the roads here in winter kills an exhaust) so I got it here magnaflow 15789, or you can try one of the vendors here, they are always running sales/specials. either way its a great system and very easy to install.