Magnaflow help, please, before I go deaf(er)

[fignewton]

My new blue baby has the MF catback system on it: 2.5 stainless through a MF resonator and then to the muffler with nice twin tips. System fits well and looks good, but the drone is a killer. Starts about 1700rpm (2.8L) and is there under any load condition until you get up over 3500 or so. The deep tone is OK, good on downshifts and idle. But the low frequency ringing is terrible. I’ve been through all the exhaust archives, searched here and the interweb and UTube, and haven’t found a Z3 fix—just complaints. Have not looked to see if/ where a Helmholz resonator could be welded into the pipe between the resonator and the muffler, but don’t think there will be enough space given the way the pipe kicks up from the diff to the rear muffler. Have seen encouraging things about the Vibrant resonators, but don’t know if there is a way to add another between the MF resonator and the muffler, or if it would work to eliminate the MF resonator and put a longer Vibrant one in its place. Anyone with a non-M got experience with this system and potential cure? Buying a new Supersprint etc is NOT an option at this time after having just bought the car. Thanks for any thoughts/experience!

[Tigershark48]

How sad. All that money spent with such a negative effect. Hopefully someone can help you out. I have an M and never have been a fan of any aftermarket sound effects, motorcycles included. I’ve yet to experience the stock sound of a non-M Z3, but more than happy with the stock M. Good luck.

[fignewton]

Thanks. It was put on 2 owners ago. Researching drone, I’m surprised that so many companies make stuff like this knowing full well that it is unacceptable to 90% of the people who buy it unsuspecting it will be that way. You look for a performance upgrade and a good sound, and then get something different for $6-800 investment. Gotta find an answer and will report.

[Tigershark48]

Back to stock?

[Vintage42]

Back to stock?

I used a Supersprint for 5 years, It was OK, did not drone, but I tired of it and reinstalled the stock. Stock BMW exhaust costs about twice of any aftermarket.

[Tigershark48]

The 2000 M that I just bought has 20k miles on it with stock exhaust. Looking at the bottom, I have to say I was really impressed with how substantial the entire exhaust looked. Even though they’re expensive, they’re probably worth it.

[wagnerism]

I just installed the TMS headers, MagnaFlow cat, and MagnaFlow cat-back.

I did some research on this and found MZ3 Coupe owners attenuating the drone by using dynamat in the trunk area.

Their theory was that they both deadened the sound and changed the resonant frequency of the space/chassis/etc.

First determine if there is anything that you can do to change the drone. That may help you identify how it starts.

Try loading the trunk with jugs of water. Or try rigidly attaching something heavy to the trunk surface.

I'm waiting to see how bad the drone is in the long term before I start working on it.

[Tigershark48]

In addition to replacing with something better, I hope those experiencing the negative side of this product are providing reviews that point this out to everybody. Magnaflow should be addressing these problems.

[Vintage42]

... I hope those experiencing the negative side of this product are providing reviews that point this out to everybody...

They are:
http://www.bimmerforums.com/forum/sh...w-14815-are-on
http://www.bimmerforums.com/forum/sh...Flow-Installed
http://forums.bimmerforums.com/forum...7#post27235077
http://forums.bimmerforums.com/forum...5#post27616895

... Magnaflow should be addressing these problems.

I don't think Magnaflow considers it a problem. They make inexpensive exhaust systems formed around their generic straight thru 4815 muffler. They proudly say "all mufflers are engineered with a wide open performance design."
For three times the cost of a Magnaflow's simplicity, Remus offers a reverse-flow muffler with a tuned sound. "... sound-engineered! ... They prototype a product after careful engineering, then put it in a sound booth and test the sound, and continue the process of re-engineering and testing until the product is perfect. Very few exhaust manufacturers have such a rigorous sound quality procedure." I think the ability to tune for a pleasing sound depends on separate inlet and outlet pipes laying side by side in an oval shell.

[Tigershark48]

Based on your review links, Magnas don’t win any awards unless the owner just digs the noise. It’s telling to see the BMW oems getting put back on within days of trying the Magnaflows. Remus sounds like a great choice, but the original may very well be as good or better as designed for the 6 cylinders.

[PhilPhil]

I used to have a VR6 GTI, and bought a Magnaflow cat-back without the opportunity to hear one on a similar car beforehand. I hated it as soon as I pulled out of the mechanic's lot. I hoped it would mellow with time, but that completely failed to happen. Horrible drone at highway speed. I lived with it for several years before I could afford to have the OEM system reinstalled.

Years later, when I got my 2000 Z3MC, the OEM exhaust sounded a little anemic to me. So, this time I went with a Supersprint. It has zero drone and a nice deep tone. The only thing I could wish for is more pop and crackle on overrun, but I suspect that's the compromise I made in exchange for the absence of drone.

I hate to say it, but I think you'll have drone as long as you have the Magnaflow on there.

[Tim95M3]

Buying a new Supersprint etc is NOT an option at this time after having just bought the car.

Don't waste your time with that. That's what I did, and the SS sounds identical to the MF. Luckily I got the SS for half price lol

[fignewton]

good to know. Just stuffed the trunk with furniture blankets and rode around. No difference, so I’d say dynamat won’t help (just as it didn’t on my Mini Cooper S with exhaust system on it).

[Vintage42]

... the SS sounds identical to the MF.... l

I used a SS on my 1.9 for five years. From what have been able to hear of the MF, the SS was better. Rather nice in its way. It did not drone on the Interstate and could not be heard above all the other noise. But on take-off it did make the 1.9 sound like the mouse that roared, and this became embarrassing. The car could not live up to its voice. I went back to stock a year ago.

[fignewton]

Thought I'd give an update on what I have done so far to quieten the MF, as there is another post below considering exhaust on the same car as I have.
I bought my car in Nov with the Magnaflow (MF) catback already on it Between about 1800 and 2300 rpm, it is loud and drones under any throttle increase. (Backing off the throttle slightly, it quietens.) I have remedied the situation somewhat by using a 2.5" diameter 3-disk insert from Car Chemistry https://www.jegs.com/i/Car+Chemistry/176/3DI25R/10002/-1?mrkgcl=1239&mrkgadid=3328188441&adpos=1o3&creati ve=330726016718&device=c&matchtype=&network=g&jegs promo=nonbrand&gclid=Cj0KC,Qjwg73kBRDVARIsAF-kEH-cgS_IJcT1fGxs0LagelwzAaykufrr0SQSU3UvqtsJMBDIn2ren e0aAkClEALw_wcB and their stainless steel packing. I have not used the two caps that come with it for the center tube of the insert. I also did two layers of sound deadening material (like Dynamat) all through the trunk and rear bulkhead interior and a layer of sound deadening mat over it under the carpet. (I did not cover all of my spot welds so that i can watch them.)
The floor pan just above the muffler works just like a tinny drum head to amplify the sound waves coming off the muffler. The noise is much more subdued now on the inside, and I can't tell that I have any detrimental loss of flow (read how the insert is supposed to work) impacting performance. Cruising isn't bad at all, and my 11 year old granddaughter doesn't think it is too loud inside. At part throttle under load at the above rpms, it still gets louder, but the car sounds powerful and great going through the gears and decelerating.
I had to grind down the edges of the discs on the insert a little with my belt sander to get them into the MF, but this seems to be standard given variations in tubing. The ONLY place to put it is in the very back part of the midpipe, where the muffler then slides over for clamping. The CC instructions say it is most effective placing it as far toward the collector as possible. I tried to see if I could get it in the front of the midpipe or just after the cat, but the way the midpipe is shaped doesn't have the length needed, and smaller diameter of the cap pipe would not work.
I may pull the muffler one day and remove the insert to test how effective it is relative to the sound deadening that I did. So far, I'm inclined to keep the MF but still may consider replacing just the muffler and using the MF tips, which are nice.

[Vintage42]

You might like to go back to the stock exhaust, if you kept it.
I used a SS for five years, enjoyed it, but now like the stock better. The SS did not drone, but was loud up the gears under throttle. I grew tired of the 1.9 sounding so powerful when it wasn't. I didn't always want to give that challenge to nearby aggressive drivers.

[jrkoupe]

99 2.8 coupe here

Mf rear can in place of oe rear muffler. Over 18 yrs on it. No drone. At all !

[fignewton]

99 2.8 coupe here

Mf rear can in place of oe rear muffler. Over 18 yrs on it. No drone. At all !

ah, but you arestill running the stock resonator too?

[jrkoupe]

ya