Magnaflow 5” full system feedback ?

Supermoto68

New member
Jan 17, 2021
26
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1
I am looking at installing the Magnaflow straight pipe system down pipe back. All 5” brand new $355.00

has anyone done this too loud for daily driver ? I understand will need a EFI live tuner.

Any feed back would be appreciated

I have a 2009 GMC HD3500 crew cab long bed 4x4 single rear wheel
 

zakkb787

<that’s not me...
Sep 29, 2014
2,340
52
48
Granite Falls NC
Had this on my lb7 straight piped. Slight drone especially axle dumped. On my 06 I have it too, but with an $80 12” flo pro resonator under the driver seat. Nearly silent in the cab. SmokinLMM was blown away with how quiet it was in the cab but still nice and throaty outside and when you get on it. The magnaflow kits are nice but not perfect. Some of the hangers require a little persuasion but nothing bad. Biggest pro to this kit vs other budget priced kits is it comes with 1” wide band clamps not u bolts. Highly recommend the flo pro twister tho as far upstream as you can possibly get it. I cut the end off the very first section coming from the DP and put it there
 
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Lanky

New member
Jun 1, 2015
27
2
3
Ive had the 5" magnaflow on my LMM for roughly 5 years. I am running axle dumped too mostly do to my laziness. The hanger at the tail end ripped off the pipe most likely because the stress put on it due to persuasion needed like mentioned above. I procrastinated getting it fix and now I seemed to have misplaced it.

The exaust sound was definetly more pleasant with tail pipe aimed away from the ground but the axle dump isnt terrible. If I had to do it all over again I'd stick with the magnaflow.
 
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Supermoto68

New member
Jan 17, 2021
26
0
1
Had this on my lb7 straight piped. Slight drone especially axle dumped. On my 06 I have it too, but with an $80 12” flo pro resonator under the driver seat. Nearly silent in the cab. SmokinLMM was blown away with how quiet it was in the cab but still nice and throaty outside and when you get on it. The magnaflow kits are nice but not perfect. Some of the hangers require a little persuasion but nothing bad. Biggest pro to this kit vs other budget priced kits is it comes with 1” wide band clamps not u bolts. Highly recommend the flo pro twister tho as far upstream as you can possibly get it. I cut the end off the very first section coming from the DP and put it there
Thank you for the feedback
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,382
46
48
38
Maryland
I personally stay away from them now, they always seemed to hit and rub on everything. 4" systems always fituch better. Maybe it's just me...
 

Lanky

New member
Jun 1, 2015
27
2
3
5" is definitely tight but if you fiddle with it enough you shouldnt have any problems rubbing.
 

lutzjk913

Well-known member
May 5, 2010
1,579
106
63
groveport, ohio
I’ve went through several exhaust systems on my trucks over the years.

MBRP
Diamond Eye
Magnaflow

hands down maganflow was the easiest to install. I’ve done it on my a LMM and LB7 and my cousins 2nd gen. Overall they are the easiest to install of those 3. Never had a issue.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,308
350
83
Central OH
5" Magnaflow here as well. Didn't have any issues with install, I don't drive mine on long trips anymore so the noise is a non issues, but maybe look into a resonator like said. FTE seems to be a popular option
 

Dozerboy

Well-known member
Jun 23, 2009
4,806
383
83
TX of course
I have one on my LBZ. I wouldn’t do it again. Either a 4”, a muffler, or both. The 5” just takes up to much space IMO just to gain a little deeper tone. While the sound isn’t bad/very loud. It’s to loud to talk to someone in the back seat without talking uncomfortably loud especially while towing.

I’m an old man in a young mans body though.
 

Josh154

Well-known member
Sep 28, 2015
1,220
84
48
Sioux Falls SD
I have one on my LBZ. I wouldn’t do it again. Either a 4”, a muffler, or both. The 5” just takes up to much space IMO just to gain a little deeper tone. While the sound isn’t bad/very loud. It’s to loud to talk to someone in the back seat without talking uncomfortably loud especially while towing.

I’m an old man in a young mans body though.

I feel like I’ve noticed opposite lol. My lmm with 4” seemed super loud, my lml with 5” seems much more quiet. Could be better cab and sound deadening though.
 

Dozerboy

Well-known member
Jun 23, 2009
4,806
383
83
TX of course
I feel like I’ve noticed opposite lol. My lmm with 4” seemed super loud, my lml with 5” seems much more quiet. Could be better cab and sound deadening though.

Yeah the 2015+ trucks are way quieter. That was the first thing I noticed when I bought my 2015. I had so much easier time talking on the phone while driving.
 

fl0w3n

Active member
Jan 8, 2015
508
25
28
I had a 5” straight pipe on my 06 ECSB, and as a single younger man I loved it and had no complaints.

With my 04 CCSB and no longer single, I’m more concerned - so I went with a 4” MBRP system with muffler. I have yet to install it, but I’ll probably go with straight pipe first and then later try installing the muffler if I find it obnoxious
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
3,905
1,073
113
Neenah, Wisconsin
IMO the Magnaflow is one of the easiest systems to install and it fits well. Sometimes, like others have posted, some of the hangers take some persuasion to get into the proper orientation but nothing bad. Their band clamps are very nice to work with as well if you ever have to adjust anything.


I have one on my LBZ. I wouldn’t do it again. Either a 4”, a muffler, or both. The 5” just takes up to much space IMO just to gain a little deeper tone. While the sound isn’t bad/very loud. It’s to loud to talk to someone in the back seat without talking uncomfortably loud especially while towing.

I’m an old man in a young mans body though.

100% agree, as a personal preference I prefer 4" over 5" but that comes down to preference.
 

LB7_01DURAMAX

Member
Apr 11, 2019
37
8
8
Ohio
I have had one on my LB7 for about five years. It’s holding up good, it was really close to trans lines, I just tweaked the lines toward trans a little bit.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
14
38
Minnesota
I have a 5” Magnaflow on my 03’ LB7 with no muffler, the biggest reason I went with it was because it’s true 5” from the front to the back, most 5” kits are 4” for about the first 4 feet, than transition into 5”. It fit pretty good for the size. I was looking for the highest flowing because truck had compound turbos and makes around 1,200hp, and didn’t want a stack.
 

Supermoto68

New member
Jan 17, 2021
26
0
1
Well, I finally made it happen installed the magna flow 5” full system and used a tuner. Sound is much better even with a Pro Flow twister. I really was surprised how easy the install went, took about 3 hours for everything. Look forward to a long drive to see if my fuel mileage gets better.

Thanks to all for your input