Magnaflow Exhaust Review (Pics, Video)

[ZyroXZ2]

Thanks for the detailed write up and follow up video. I've got the Magnaflow on order, and will be mating it with the Jun BL down pipes. I wonder if that combo will be a tad more aggressive. One though I had was doing a 2.5" hole saw cut into the end of the Helmholtz resonator, and welding on a flange for an electric cut out. That might give it a bit more sound. You could use the Varex smartbox controller to program the opening to your liking. It connects to OBD2 port and will open and close based on TPS, RPM and speed. You can also geo-fence it in quiet mode ( ie cold starts at home not to annoy neighbors. check it out: Varex Smart Box

Oh I'm sure there's plenty of ways to rig up something to valve up the exhaust flow, but... I don't really want to fiddle with modes or switches for on-the-fly responses to traffic conditions. Someone in another forum suggested one of the boxes that hooks up to the OBDII and can sense throttle position. That seems the most viable idea, but also serves to drive up the cost substantially while the Magnaflow system wasn't really designed with these things in mind... *shrug* Can't have it all I guess, lol

 

[KLR STINGER]

The link I included to the Varex smart box is exactly that. IT connects to OBDII and uses TPS, RPM, and Speed PIDs to create a 3 axis map relative to the position of the valve. Given the low cost of the magnaflow system, you can;t expect features from exhausts that typically cost several thousand dollars. It would probably add around $5-600 in cost, but if it gets you what you want...is it worth it to you?

 

[ZyroXZ2]

The link I included to the Varex smart box is exactly that. IT connects to OBDII and uses TPS, RPM, and Speed PIDs to create a 3 axis map relative to the position of the valve. Given the low cost of the magnaflow system, you can;t expect features from exhausts that typically cost several thousand dollars. It would probably add around $5-600 in cost, but if it gets you what you want...is it worth it to you?

You might be reading into me a bit too far: I'm not asking for all that on the Magnaflow... I'm stating I recognize there are ways around it, but what I would really want is a well-tuned catback. Then, less parts, less things to go wrong, tuned to balance sound with performance. Boom.

 

[ZyroXZ2]

Just providing a sort of shout-out update:

Props to John over at hottexhaust.com for getting me a replacement muffler for the one damaged in transit. I'll finally be swapping that out and working on pics hopefully by the end of the week. Though, I suspect most of you don't care so much about the looks as opposed to the sound, but I'm a man of my word: I said I'd get pics and I will [biggrin]

 

[ZyroXZ2]

I promised pics, and at the end of this is my finalized review:

Just some pics of the exhaust "tips" behind the fascia. They're painted with black primer (though one of them is already flaking off a bit), and are quite a bit off center (more on that later):




Here are pics of the mufflers and attached Helmholtz resonators. You can see dents on the passenger side, and the driver's side one looks nice and new thanks to hottexhaust.com replacing it as it had a big dent in it that couldn't obviously be caused by installation:




Here are shots of the resonators just after the X-pipe. Note that there is VERY little clearance with the bracing bracket (1/4" at best), and that the exhaust is NOT centered. You can see how the driveshaft is off-center in comparison:




And finally the overall fitment indicated by the first set of exhaust hangers. I loosened and tried to realign everything multiple times, and without actually modifying the exhaust system itself to correct for this (bend/rewelding hangers, cutting off pipe/flanges to change lengths), it just doesn't hang right on its own. I chose to take the win where I could and adjusted the mufflers at the slip joint to ensure the muffler hangers are hanging perfectly vertical.




But wait, there's more! I really hated that cheesy "mf" plate, and thanks to my buddy at his work, he made some bars per my measurements to place across. I then painted them in black primer and clear coat.



REVIEW:

I've had the exhaust on for well over 500 miles to allow for break-in (including some extra WOT runs to purposely "blow out" the glass pack as much as possible surrounding the steel wool). It's volume has increased since first installation, and it sounds more balanced with a slightly more aggressive overall tone. However, the medium engine load resonance is still there while full throttle lacks the roar it really deserves. The fitment isn't quite perfect, and it takes some physical modifications to get right: simply loosening everything and reshifting/repositioning isn't quite enough and some part of the exhaust system remains in "tension" otherwise. It does come with a butt dyno improvement, something I'm confident enough in telling someone to dyno test to corroborate. How much gains the butt dyno can never accurately tell, but there is definitely something opened up towards the upper RPMs at the cost of shifting the torque band a bit. If you're into a more "executive express" exhaust rather than "hi I'm loud", this is the exhaust for you. It's not perfect by any means, but presents an alternative to trying to make the Stinger sound like its engine means business out the back end by giving a more subtle and classier "sporty" sound to your tailgaters.

 

[Johnny B]

Excellent review ZyroXZ2. I just installed the Magnaflow last Friday. Took just under 40 minutes and the fit and finish is of good quality. Every thing lined up where it was supposed to. I never liked the factory chrome tips so I replaced them with carbon fiber units. That took a couple of hours to make fit. Very careful plastic removal around the existing bumper holes using a dremel cutting wheel and razor blade was used. Sound is what I expected. A nice and deep rumble without any drone. Just enough noise under load to differentiate from stock. Power increase is definitely noticeable. From 3500 rpm to redline it pulls much harder and allows the turbo to spool up quicker. The increase is helped by the additional addons I have on the car. RaceChip Black with the upgraded more aggressive race mode, XLR throttle controller, K&N drop in filters, gapped stock spark plugs .024 and using 94 octane fuel. For fun I created a vinyl over lay for the front and steering wheel emblem. The only other upgrade I plan to do in the future is to replace the intercooler. I have Eibach's installed and am waiting on my 20" rims to arrive. I will post additional pics once the new wheels are installed. View attachment 9058 View attachment 9059 View attachment 9060 View attachment 9061 View attachment 9063

 

[KLR STINGER]

Those CF tips look great. I was thinking of doing the same thing. What size Did you use, and is it 4 single tips? What size and how did you attach them? Did you just make a bracket and screw into the valance like OEM, or are the connected to the pipes? Did you just enlarge each hole in the valance, or did you cut a big oval out? Where did you get the tips?

 

[robz32]

Those tips look great!!....Nice work @Johnny B

 

[ZyroXZ2]

Excellent review ZyroXZ2. I just installed the Magnaflow last Friday. Took just under 40 minutes and the fit and finish is of good quality. Every thing lined up where it was supposed to. I never liked the factory chrome tips so I replaced them with carbon fiber units. That took a couple of hours to make fit. Very careful plastic removal around the existing bumper holes using a dremel cutting wheel and razor blade was used. Sound is what I expected. A nice and deep rumble without any drone. Just enough noise under load to differentiate from stock. Power increase is definitely noticeable. From 3500 rpm to redline it pulls much harder and allows the turbo to spool up quicker. The increase is helped by the additional addons I have on the car. RaceChip Black with the upgraded more aggressive race mode, XLR throttle controller, K&N drop in filters, gapped stock spark plugs .024 and using 94 octane fuel. For fun I created a vinyl over lay for the front and steering wheel emblem. The only other upgrade I plan to do in the future is to replaceView attachment 9064 View attachment 9065 View attachment 9066 View attachment 9067 View attachment 9068 the intercooler. I have Eibach's installed and am waiting on my 20" rims to arrive. I will post additional pics once the new wheels are installed. View attachment 9058 View attachment 9059 View attachment 9060 View attachment 9061 View attachment 9063

*GASP* You covered the Kia logo

Also, hmmm... My mufflers WERE both damaged in transit, that makes me wonder if more than that was damaged during shipping if yours fits perfectly.

 

[soulevo8]

I didn't inspect my rubber hangars closely, but I didn't have any fitment issues at all. Everything seems centered and sounds great. I kinda like the MF plate. It's subtle enough that most people won't notice it anyway. I totally agree with your assessment of the tips being too visible. I may get some high temp black spray paint and paint all the way back to the canister.

 

[ZyroXZ2]

I didn't inspect my rubber hangars closely, but I didn't have any fitment issues at all. Everything seems centered and sounds great. I kinda like the MF plate. It's subtle enough that most people won't notice it anyway. I totally agree with your assessment of the tips being too visible. I may get some high temp black spray paint and paint all the way back to the canister.

Part of me is worried that people will think I think I'm some "badass mf"... The mufflers both already have the full logo in it, I think it's a bit overboard That, and the plate is horribly un-aerodynamic

 

[ZyroXZ2]

Just thought I'd provide an unusual update:

As some on the forum know, I'm now on a second Stinger. Some quick backstory, I already noted in my thread about why I no longer have my first Stinger that my 2019 GTS stock exhaust is MUCH louder than my 2018 ever was. Though, the car seems overall louder in the cabin to me for some reason, so I've yet to determine if this is a change in sound deadening (weight reduction or cost reduction) or an actual change in internal baffling/design of the stock exhaust.

Now that I put a new set of the Magnaflow on, it is ALSO significantly louder than when I put a set on my 2018. I can't tell whether Magnaflow has made changes to make their exhaust louder, or the fact that both the stock and Magnaflow are so much louder on my 2019 indicates something else entirely. I do have audio engine enhancement off (obviously), but it begs the question of where that sound is monitored from to begin with. If it's some sort of opening or baffles (like BMW used to use to let more engine noise into the cabin), then it's more that my 2018 was extra quiet rather than my 2019 being louder.

I thought I'd note this because if Magnaflow has changed the internal steel wool/fiberglass packing ratios, it could affect overall volume and thus expectations. Put simply, this is still likely the quietest aftermarket exhaust, but if it's not my 2019 GTS, then the newest versions are significantly louder right out of the box.

All kinds of shrugging has happened as I've scratched my head on why my exhaust experiences are night and day between my 2018 and 2019.

 

[Toddasaurus]

Just thought I'd provide an unusual update:

As some on the forum know, I'm now on a second Stinger. Some quick backstory, I already noted in my thread about why I no longer have my first Stinger that my 2019 GTS stock exhaust is MUCH louder than my 2018 ever was. Though, the car seems overall louder in the cabin to me for some reason, so I've yet to determine if this is a change in sound deadening (weight reduction or cost reduction) or an actual change in internal baffling/design of the stock exhaust.

Now that I put a new set of the Magnaflow on, it is ALSO significantly louder than when I put a set on my 2018. I can't tell whether Magnaflow has made changes to make their exhaust louder, or the fact that both the stock and Magnaflow are so much louder on my 2019 indicates something else entirely. I do have audio engine enhancement off (obviously), but it begs the question of where that sound is monitored from to begin with. If it's some sort of opening or baffles (like BMW used to use to let more engine noise into the cabin), then it's more that my 2018 was extra quiet rather than my 2019 being louder.

I thought I'd note this because if Magnaflow has changed the internal steel wool/fiberglass packing ratios, it could affect overall volume and thus expectations. Put simply, this is still likely the quietest aftermarket exhaust, but if it's not my 2019 GTS, then the newest versions are significantly louder right out of the box.

All kinds of shrugging has happened as I've scratched my head on why my exhaust experiences are night and day between my 2018 and 2019.

Maybe Kia secretly installed an e-cutout on each downpipe that automatically opens when at WOT.
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Nah I'm jk. Lol.

 

[Drudge]

Do you just have the exhaust or did you pair it with down/mid pipe?

 

[mandasol]

I have a magnaflow catback installed on my 2.0 and I went through quite the ordeal with interior sound. It seems it makes a huge difference where the tail pipe terminates. The kit tail pipe ends just shy of the fake factory tips and this causes a lot of the exhaust sound to bounce back under the trunk of the car and reverberate very loudly. Just by extending the end of the exhaust by either clamping on tips or welding on extensions and getting the exhaust to exit out just a little further decreases the sound drastically. This is just a guess, but by looking at the pictures of your '18 it looks like the damage you mentioned also might have unintentionally caused the tips to extend a little further out into the factory tips just enough to keep the sound from reverberating back under the trunk.

On a side note, I notice my kit (for the 2.0) doesn't come those mufflers past the axle, just Helmholtz resonators. I think that's why the magnaflows for the 3.3 sounds only slightly louder than stock, but the kit for the 2.0 sounds way louder than stock.

 

[ZyroXZ2]

Maybe Kia secretly installed an e-cutout on each downpipe that automatically opens when at WOT.
.
.
.
.
.
.
.
Nah I'm jk. Lol.

Yea, I'm sure you know how loud that would actually be, lmao

Do you just have the exhaust or did you pair it with down/mid pipe?

It's not about the pairing, though right now it's just the catback. It's that compared to my 2018 in the same exact conditions (again, when it was just the catback), it was barely louder than stock. This time, it's like a whole different exhaust system except the mid-range RPM resonance is still there.

I have a magnaflow catback installed on my 2.0 and I went through quite the ordeal with interior sound. It seems it makes a huge difference where the tail pipe terminates. The kit tail pipe ends just shy of the fake factory tips and this causes a lot of the exhaust sound to bounce back under the trunk of the car and reverberate very loudly. Just by extending the end of the exhaust by either clamping on tips or welding on extensions and getting the exhaust to exit out just a little further decreases the sound drastically. This is just a guess, but by looking at the pictures of your '18 it looks like the damage you mentioned also might have unintentionally caused the tips to extend a little further out into the factory tips just enough to keep the sound from reverberating back under the trunk.

On a side note, I notice my kit (for the 2.0) doesn't come those mufflers past the axle, just Helmholtz resonators. I think that's why the magnaflows for the 3.3 sounds only slightly louder than stock, but the kit for the 2.0 sounds way louder than stock.

I don't mean it in a rude way, but this isn't about the Magnaflow itself, it's that somehow on my second Stinger, what I got is completely different than my first one. It hums just sitting there idling. I even swapped the rear slip joint clamps for V band clamps, AND I had the stock tip backing plates cut off and welded to my Magnaflow to deflect more sound from the hatch area (which works, btw).

It's just... strange... But per before, my stock exhaust was also significantly louder, so it might not be the exhaust for all I know. I'm just baffled (ha ha) at the differences between the two.

 

[Toddasaurus]

It's really interesting that there is a difference in sound, both in stock form and with the MF exhaust for the GTS.

It makes me wonder if Kia did some changes to the ECU tune which makes it sound a little louder. Or, possibly higher flowing cats in the primary and/or secondary downpipes? OR, like you said, maybe MF changed their exhaust system a little bit since you originally bought yours back with you had your older Stinger....but, that doesn't really account for your new GTS being louder when it was fully stock.

Out if all those options, I bet it's actually what you mentioned that I hadn't - sound deadening. I bet there is less in the GTS compared to your old Stinger, whatever trim it was.

Actually, now that I think about it - my vote is that it's all just in your head. Haha.

 

[ZyroXZ2]

It's really interesting that there is a difference in sound, both in stock form and with the MF exhaust for the GTS.

It makes me wonder if Kia did some changes to the ECU tune which makes it sound a little louder. Or, possibly higher flowing cats in the primary and/or secondary downpipes? OR, like you said, maybe MF changed their exhaust system a little bit since you originally bought yours back with you had your older Stinger....but, that doesn't really account for your new GTS being louder when it was fully stock.

Out if all those options, I bet it's actually what you mentioned that I hadn't - sound deadening. I bet there is less in the GTS compared to your old Stinger, whatever trim it was.

Actually, now that I think about it - my vote is that it's all just in your head. Haha.

Oh it's most definitely not in my head, lol