View Full Version : Review & Install Tips for Magnaflow E46 M3 Catback


SilverState
12-19-2005, 03:10 AM
I installed the Magnaflow today. I have the stock airbox/filter, stock headers, and stock program.

A couple of installation tips before I forget:

If you are going to do the job yourself, you really should have two people. It is not that it is a difficult job, but an extra set of hands really comes in handy.

Before you begin, go to the hardware store and get a bunch of washers in two sizes. One stack (around 4 inches) should be of a size slightly bigger than 1/4". The second stack (around 3 inches) should be of 3/8" or slightly smaller. You won't use all these washers, but it is better to have more and not need them, than to have to run back to the hardware store. All of these washers will be used to shim the body crossmembers (the two straight ones and the v-shaped one).

Before you get to work, you will need to jack the car up. Use a rack with rubber inserts and be careful not to contact the side skirts. In the front, on the passenger side, make sure your jack gives you enough room to work with the exhaust pipe.

As for tools, you are going to need various sockets, some deep, some swivel, and a 12 point 10mm (I think) for the flange that goes to the headers. I guess you could use the box end of a combo wrench for that, but it must be thin. An air ratchet is nice. A short open end 13 or 14 will also be needed for that same flange. Some of the sizes that come to mind are 3/8 and 10mm-16mm. A tranny jack is really helpful as well, especially when removing the stock muffler.

Removing the exahaust was fairly straightforward as indicated in the Magnaflow instructions. One thing, the driver's side of the stock muffler HAS TWO BRACKETS and you will need a deep swivel socket and a long extension to get to the nut that is the right inside the bumpercover. Undo that one first.

As to my review of the exhaust:

Let's start with the kit. I appears to be a high quality kit. All stainless steel packaged very nicely and protected with bubble wrap, paper, and foam. The hardware is thick and grade 8 bolts. The instructions are okay, but could use some more info about the driver's side rear bracket and the 12pt. flange bolts. But overall, I have bought kits for twice the money that were half as good.

Fitment. Everything lined up well. I did not have to cut or pry or use heat wrap/sleeves for anything. The only inconvenience, like I said, was having to shim the cross members for clearance. Also, my tips are not perfectly aligned - the driver's side sits a little lower than the passenger side. But the casual observer would never notice.

Now the good stuff. Sound. I was a little concerned that the sound would be ricey. I am used to V8s and I was dreading the shound of a ricey Honda coming from my $50K BMW. I was pleasantly surprised when I turned the key. THIS IS HOW THIS CAR SHOULD HAVE COME FROM THE FACTORY. It now sounds like a sports car. It is classy and aggressive at the same time. Absolutely perfect. No drone, no vibration, no stalling, no codes, none of that. With the radio on, you can hardly hear it. But I drove with the radio off, so I could hear and enjoy the sound of my Motorsports 3 Series.

Performance. A friend of mine is tracking down a GT1 so I can put my car in dyno mode and do some pulls when I am in L.A. I will let you know the exact numbers. By then, I will have some other things done as well. But SOTP tells me this thing is quite a bit quicker - wraps out smooth and fast.
Weight. This kit is WAY lighter than stock. Less weight, quicker acceleration, shorter stopping distance, more nimble, etc.

CONCLUSION: Excellent value in many ways and no regrets.

BMRSEB
12-19-2005, 09:48 AM
SilverState.. Here's (http://forums.bimmerforums.com/forum/showthread.php?t=441487&referrerid=6813) an addendum to your post and just as informative..:) Now thanks to you two guys, I'm even more convinced about the Magnaflow.:cool

Now the "Help Fund my Magnaflow" fundraiser begins!!:stickoutt

SilverState
12-20-2005, 01:35 AM
You don't need a fund. The kit is VERY REASONABLY PRICED. I bought mine from Bob at Bimmer Performance Store ($20 less than anyone else).

BimmerPerfStore
12-20-2005, 01:45 AM
SilverState.. Here's (http://forums.bimmerforums.com/forum/showthread.php?t=441487&referrerid=6813) an addendum to your post and just as informative..:) Now thanks to you two guys, I'm even more convinced about the Magnaflow.:cool

Now the "Help Fund my Magnaflow" fundraiser begins!!:stickoutt

Send me an e-mail at sales@bimmerperformancestore.com or call us at 805.482.1234. We only have a couple left at the blow-out price. This system is without a doubt the best bang for the buck exhaust option for the E46 M3.

You can see and hear the exhaust at our site here:
http://www.bimmerperformancestore.com/store/pc/viewPrd.asp?idproduct=202

Bob

SilverState
12-24-2005, 08:34 PM
I installed a Streamline Engineering (SE) air filter and sharked it.

The result is that the throttle is more responsive and it revs easier.

I was also getting a little vibration in the mornings on a cold start. One of the little crossmembers (the one with the rubber bushings), was too close to one of my pipes. I gave it a little "love" with a hammer and now it clears nicely.

SilverState
02-26-2006, 06:38 PM
Latest update on the clearance issues.

I took my car in to have a ssk and gears done. So the shop had to pull my exhaust down and put it back up without the washers/shims on the front short straight cross-members. In the morning, I would get a little noise/vibration from those areas.

Today, I racked my car to see where the morning noise/vibration was coming from. Sure enough, it was from the short straight cross members. They are not entirely flat. They have raised areas that touch the exhaust during a cold start. So I market the areas where they were close, removed both cross-members (one at a time), and flattened the raised areas where I had marked them. I then put them back up with some blue locktite and it appears that I don't have any clearance issues with the short straight crossmembers and do not need any washer/shims in that area.

As for the rear v-shaped cross-member, I ended up using 4 fender washers on each of the side mounting points and 8 fender washers on the rear middle mounting point. Again, it appears that I have plenty of clearance for the cold starts.

Another interesting thing I noticed while I had my car on the rack is that since I recently installed the Eibach pro kit, I have been scraping a little while pulling into my work's parking garage (steep incline and then flat witout room to take at an angle). I was wondering what part of my car was scraping. Turns out it is the front part of the Magnaflow resonator. I take it slow and it that part of the exhaust is real beefy, so I don't think I am going to have a problem, but at least now I know what the lowest part of my car is.
Just thought I would share in case someone else is having some vibration/noise/scraping issues with the Magnaflow.

It seems like a pain to have to do these things, but if you know to do it going into it, you can do it from the start and not have to mess with it. Set it and forget it. The next thing I am going to do is have an exhaust shop put a torch to the rear brackets and move the tips up a little. Once that is done, it will be perfect.

hnoppenberger
02-28-2006, 11:37 PM
if one side hangs down more than the other, then its not a very good fitment.

SilverState
03-01-2006, 12:23 AM
if one side hangs down more than the other, then its not a very good fitment.

For under $800 for the entire stainless catback exhaust system, I have no problem paying an exhaust shop a few bucks to line the tips up. I would rather do that than spend a couple grand for just a muffler. :rolleyes