Magnaflow 18" Muffler Install

[I Love Grits]

Replaced the stock muffler with a Magnaflow 18". You'll need a center/offset pattern to make it easiest (the only offset/offset is in a polished finish and wasn't worth the added price). Inlet is a single 3" and as mentioned in another post, outlet is now 3" (vs. dual 2.5" of previous gen).

Part # used here is 12259. Guy at the muffler shop said everything lined up easily enough and he only had to add a short extension piece to the front of the inlet.

Its been a while since I've had a vehicle with an aftermarket exhaust, so I'm not used to being able to hear anything. That being said, I'm very happy with the 18" so far - it has a nice rumble at idle in the cab, is evident during acceleration, but mutes down nicely when ambling along to a faint background hum.

I haven't ridden in it enough to give an opinion about MDS drone that some guys report with previous gen at +/- 70 MPH cruising. Will update if there is an annoying drone.

 

[devildodge]

Keep us uodated. Awesome so far

 

[Agitated]

Glad you like the muffler. I'd keep an eye on those welds, they look like ****e and are full of pinholes. That will be a magnet for rust through.

 

[I Love Grits]

Glad you like the muffler. I'd keep an eye on those welds, they look like ****e and are full of pinholes. That will be a magnet for rust through.

Thanks for the feedback. I'll put some header paint or cold galvanizing compound on them.

 

[I Love Grits]

Update:

After a couple of weeks with the louder muffler on, I'm still very happy with the swap. However, it makes me haaaaate MDS. With the stock muffler, if I was really paying attention, I could hear a change in the exhaust when MDS kicked in but for the most part it was unnoticeable.

With the louder muffler it is annoyingly noticeable. Speeds from 35-75 don't make a difference (I think its because the transmission is always hunting for the highest gear so its not unusual to be in 8th gear at 40 mph) as soon as the MDS turns on, the tone drops to a much deeper rumble and the resonance can be felt throughout the cab.

With slight throttle inputs the truck sounds almost like its bogging down as the MDS tries to stay engaged. Once it disengages, the tones jump back up in pitch and the sound is much fainter.

With a louder muffler you will really notice how often the MDS kicks on/off. It annoys me so much that I've decided to keep MDS turned off by selecting -8 on the gear limit as you could do in 4th gen trucks.

 

[John813]

Figured. Assume this would still show up even with the full catback system by Magnaflow.
Anywho, no big deal for me as I turn that off asap.

 

[Rustydodge]

Could you post a video so we can hear how it sounds at idle/rev?

 

[I Love Grits]

Could you post a video so we can hear how it sounds at idle/rev?

I have only an iPhone to record audio/video with and it didn't do a good job picking up the sound. Truthfully though, any YouTube video with the 5.7L and Magnaflow that was filmed with better equipment will give you a good representation.

Sorry I couldn't help much. If you want to see the video I can post it anyways.

 

[riccnick]

Dude, of course we want the video, crap quality and all!

 

[768mph]

Update:

After a couple of weeks with the louder muffler on, I'm still very happy with the swap. However, it makes me haaaaate MDS. With the stock muffler, if I was really paying attention, I could hear a change in the exhaust when MDS kicked in but for the most part it was unnoticeable.

With the louder muffler it is annoyingly noticeable. Speeds from 35-75 don't make a difference (I think its because the transmission is always hunting for the highest gear so its not unusual to be in 8th gear at 40 mph) as soon as the MDS turns on, the tone drops to a much deeper rumble and the resonance can be felt throughout the cab.

With slight throttle inputs the truck sounds almost like its bogging down as the MDS tries to stay engaged. Once it disengages, the tones jump back up in pitch and the sound is much fainter.

With a louder muffler you will really notice how often the MDS kicks on/off. It annoys me so much that I've decided to keep MDS turned off by selecting -8 on the gear limit as you could do in 4th gen trucks.

Great review and honest. Worst thing is when people lie about drone and MDS sound change.
Thank you. I was hoping the magnaflow would do well on this new set up. As well as the new cat back coming out, but doubtful.

 

[67 RT]

I’ve got the same muffler installed and I love it. Sounds great but is still respectable to the interior noise and public annoyance factors. Sounds much deeper than factory and is just what I was looking for. I, however, do not noice any weep hole leaking sound or drone. It is a deeper sound for sure but I don’t notice a resonance that I would associate with drone at any speed.

 

[Ajcastro]

Replaced the stock muffler with a Magnaflow 18". You'll need a center/offset pattern to make it easiest (the only offset/offset is in a polished finish and wasn't worth the added price). Inlet is a single 3" and as mentioned in another post, outlet is now 3" (vs. dual 2.5" of previous gen).

Part # used here is 12259. Guy at the muffler shop said everything lined up easily enough and he only had to add a short extension piece to the front of the inlet.

Its been a while since I've had a vehicle with an aftermarket exhaust, so I'm not used to being able to hear anything. That being said, I'm very happy with the 18" so far - it has a nice rumble at idle in the cab, is evident during acceleration, but mutes down nicely when ambling along to a faint background hum.

I haven't ridden in it enough to give an opinion about MDS drone that some guys report with previous gen at +/- 70 MPH cruising. Will update if there is an annoying drone.


View attachment 1095

for 2020 ram 1500 hemi is 3" offset in and 3" offset out?

 

[Mopar_maxi]

I had a borla 40353 put on mine. Offset inlet and outlet and I’m loving it.

 

[ChadT]

Figured. Assume this would still show up even with the full catback system by Magnaflow.
Anywho, no big deal for me as I turn that off asap.

So I have the full magnaflow system. According to the tape measure, I think it's their 22in magnaflow muffler.
Not gunna lie I think the drone is extremely acceptable, very well managed. A smidge of drone is detectable to some degree even with the giant trashcan stock exhaust, that breathes horribly and makes the V8 too quiet to enjoy!

In my opinion the magnaflow system is a good option for someone who wants to hear their engine, have a freer flowing exhaust, and have a manageable noise level for neighbors and highway drone.