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Magnaflow Exhaust Review (In-Progress, Pics Video Upcoming)

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#1
Magnaflow Exhaust Review

Hello everyone! New to the forums, first post, didn't want to waste the time with an introduction and just dive right into the good stuff we all know and love: modding!

I received the first run of Magnaflow catback exhaust back on 5/31, and then FedEx gave me blue balls and had a strange delivery exception so it instead arrived on 6/1 despite being out for delivery on 5/31. [8] I promptly put my rear tires up on ramps and jacked the front half up so that I could do a "ground" catback installation since I'm all by my lonesome but a fairly competent garage mechanic. Other than an RMA process I'm currently undergoing due to the exhaust being damaged (read: three dents; one big one on the driver side muffler and two tiny ones on the Helmholtz resonator on the passenger side) and my dumbass not inspecting it before slapping it on the car, I have enough miles on it to get a feel for what to expect when the glasspacking "settles" and it becomes louder.

LOOKS:

It looks a little "ricey", admittedly. I am thinking of fabbing up a "normal" plate bracket instead of their "mf" logo. The exhaust "tips", if you will, do not have the covering plate that the factory exhaust has nor are painted black like the factory exhaust. Thus, I painted the exhaust "tips" with black primer to hide them. Otherwise, the piping is very easy to see through the facia tips and it's a bit of an eyesore.
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.



SOUND:

This is about a wash in terms of what's good and what's bad. The good is that the exhaust has no drone at cruising speeds whatsoever. In fact, the low tone "hum" is so mellow that you could easily mistake this for being factory exhaust. That is until you give the car medium engine load. This is somewhat RPM independent: you could give the car medium engine loads accelerating, but then be cruising at the same RPM at 80MPH and not even know you have an exhaust on the car since road/wind noise covers it up entirely. What happens at medium engine load? Resonance. The exhaust system resonates and is enough to vibrate the cabin. At this point, my giblets might have moistened up at the idea of going WOT. So I did. And it sounded like... stock. Yes, the exhaust system is quieter at WOT than it is at medium engine loads. The noise of the engine overwhelms the exhaust, and as a car enthusiast, that is all bad for an aftermarket exhaust. This concept is backwards: it should still be quiet at medium load, and then sing songs of thousands of explosions happening in my engine for the world behind me to hear at WOT. So, it's great that there's absolutely no drone, but it's all bad that it's louder at medium throttle due to resonance. As a final closing good note, though: if you wanted the "executive express" experience with an aftermarket exhaust, this one is essentially what you want... with the said exception of medium engine loads.

Update - The glasspacking is finally beginning to settle and compact itself due to the moisture and heat of engine cycles and driving around. Thus, it's getting a bit louder and closer to its "nominal" state. With it being a little more loud, it does balance out the resonance by being louder overall so that the resonance doesn't stand out so much. This is a very tiny victory, though. I also decided to give it a quick WOT under a short overpass to listen to the echo off the walls, and it still sounds so close to stock I almost can't tell from inside the car. However, my schedule is pretty hectic and I'm awaiting an RMA replacement, so I still won't have sound clips for awhile as the new RMA replacement muffler will have to go through this same settling process before I record it.

Update - Quick exhaust video posted just below. Used a lavalier mic and mounted on the rear fascia outside the vehicle and then again on the inside against the driver's side headrest.

[video=youtube_share;u0-5An65wR0]https://youtu.be/u0-5An65wR0[/video]

POWER:

The torque power band does feel like it's changed. Instead of the factory slam-you-into-your-seat feel, it still plants you in place but does more of a build up to what seems to be a harder pull up top past 5k RPMs. That would make sense, of course: by doing a consistent piping diameter through perforated straight through mufflers, you effectively decrease back pressure which inherently shifts the torque curve upwards in the power band. Since the turbos can push more air out at higher volumes, the power increase would naturally be almost all top-end power. I'll continue to update this section as I keep driving it to compare.

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.
 
Last edited:

Kale808

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#2
Great review [MENTION=1100]ZyroXZ2[/MENTION].
 

Johnny B

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#5
Did you notice any increase in power or improved throttle response from adding this exhaust system?
 
OP
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Thread Starter #6
Did you notice any increase in power or improved throttle response from adding this exhaust system?
I saw your post in the other forum, and for some odd reason I can't reply over there because it claims I'm adding a picture [8] So here's a copy and paste from my reply over there that can't post, lol -

On the good ol' butt dyno, it was a pretty big leap in power that could range from 15-20HP. However, since that was late at night when the air was a nice and cool 65 degrees F, I decided I'd wait until the next day to test it. Well, the next day decided to be 85 degree weather and mild traffic so I haven't had an opportunity to corroborate my own butt dyno with a repeat. It DID feel more powerful, though, and Magnaflow is just a straight-through perforated core design. I haven't commented on "power" in my review, yet, because I haven't had a chance to do consistent runs on different days and conditions to compare to how it felt before. Of course, with the weather warming up day-by-day, I have no clue whether I can get a solid feel for it. I will update the thread as I gather pics, videos, etc., though!
 

Johnny B

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#7
Much appreciated thanks. I hope to receive my Magnaflow exhaust this week and was hoping it would be an upgrade. Thanks to your review it sounds like it will be.
 

robz32

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#9
Great review. Thanks for sharing.
Can't wait for the video and photos.
 
OP
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Thread Starter #10
Just posting a little update since I decided I'd give it a little more juice today on my trip to get some brown rain lunch (read: Taco Bell).

SOUND:

Update - The glasspacking is finally beginning to settle and compact itself due to the moisture and heat of engine cycles and driving around. Thus, it's getting a bit louder and closer to its "nominal" state. With it being a little more loud, it does balance out the resonance by being louder overall so that the resonance doesn't stand out so much. This is a very tiny victory, though. I also decided to give it a quick WOT under a short overpass to listen to the echo off the walls, and it still sounds so close to stock I almost can't tell from inside the car. However, my schedule is pretty hectic and I'm awaiting an RMA replacement, so I still won't have sound clips for awhile as the new RMA replacement muffler will have to go through this same settling process before I record it.

POWER:

The torque power band does feel like it's changed. Instead of the factory slam-you-into-your-seat feel, it still plants you in place but does more of a build up to what seems to be a harder pull up top past 5k RPMs. That would make sense, of course: by doing a consistent piping diameter through perforated straight through mufflers, you effectively decrease back pressure which inherently shifts the torque curve upwards in the power band. Since the turbos can push more air out at higher volumes, the power increase would naturally be almost all top-end power. I'll continue to update this section as I keep driving it to compare.
 
OP
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Thread Starter #11
Thanks for the review. Did you happened to take any pictures before you installed it?
I did, actually, but they're just the "friends, family, and maybe possibly" social media pics you take to say, "LOOK AT WHAT I'M DOING TONIGHT!". They're useless to car enthusiasts, lmao
 
OP
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Thread Starter #13
I'm aware, lmao... Though it could be a few weeks before I have everything squared away in terms of pics AND video clips (I don't use cell phones to record, that's just offensive, lol) [^]
 
OP
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Thread Starter #14
Update - Quick exhaust video posted just below. Used a lavalier mic and mounted on the rear fascia outside the vehicle and then again on the inside against the driver's side headrest.

[video=youtube_share;u0-5An65wR0]https://youtu.be/u0-5An65wR0[/video]
 

Johnny B

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#15
Any updates on power improvements or throttle response? Sounds real nice to me. I should have my Magnaflow delivered this week and hopefully installed on the weekend.
 

robz32

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#16
thanks for the update. Great video!!
How is the sounds at highway speeds? (60 to 75 mph)
Any drone during those speeds?
 
OP
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Thread Starter #18
Any updates on power improvements or throttle response? Sounds real nice to me. I should have my Magnaflow delivered this week and hopefully installed on the weekend.
Same as before: car no longer slams me in my seat, but more pushes me into my seat with a stronger 5k+ RPM pull.

thanks for the update. Great video!!
How is the sounds at highway speeds? (60 to 75 mph)
Any drone during those speeds?
As mentioned: at those speeds, the road/wind noise drowns it out entirely (which is why I skipped those speeds).

Great video [MENTION=1100]ZyroXZ2[/MENTION], thanks for this.
I know I'm slow on getting the pics, but there's a good reason for that, I promise! [biggrin]
 
OP
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Thread Starter #19
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]
 
OP
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Thread Starter #20
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.
 

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