[bhong]

I had the stock comp exhaust cut and replaced with the MPE so the stock midpipe was already cut. Will the AA midpipe bolt right up without further cutting or the need for adapter pieces? I am getting conflicting information on forums and from AA directly. Would love some insight from a member who has this exact setup. The AA instructions say to cut from the resonator weld 6.25in from driver's side and 1.5in from passenger. I checked under the car and looks like driver's side is ok but passenger side looks more like 3in from the weld which make's me believe the midpipe connection on that side will come short and needs more material to mate up.

[allinon72]

I have this setup and had to have the connecting pipes extended in order to reach the MPE back section.

[bhong]

Thank you! This confirms my speculation because looking under the car there is no way the AA connecting pipes will meet even with the provided clamps since there is so much distance between the two. This is similar to the Akrapovic setup since the measurement is taken from the center of the resonator vs at the weld and the cut is made further down. I've attached pictures for the M Performance, Akrapovic, and Active Autowerke instructions.

[bhong]

Originally Posted by allinon72

I have this setup and had to have the connecting pipes extended in order to reach the MPE back section.

Do you recall if your MPE was installed using the factory instructions? If so, did you have to weld extensions to both driver and passenger connecting pipes, and how long each side?

[allinon72]

Originally Posted by bhong

Do you recall if your MPE was installed using the factory instructions? If so, did you have to weld extensions to both driver and passenger connecting pipes, and how long each side?

MPE was port installed so yes it was installed using factory instructions. As you can see in the pic above, both pipes had to be extended. The previous owner tried to connect the 2 using a short length of pipe and double exhaust clamps, which failed miserably and leaked like crazy. I had the extensions tig welded on to make it right.

[bhong]

I'm glad you fixed the mickey mouse job lol. Thanks for your input and I hope this helps future MPE owners trying to pair with the Active Autowerke midpipes. This should apply to both single and equal length since the cuts are made in the same spot. My AA single resonated midpipe is now up for grabs in the Classifieds(https://f87.bimmerpost.com/forums/sh....php?t=2059890).

[mike@x-ph.com]

Originally Posted by allinon72

I have this setup and had to have the connecting pipes extended in order to reach the MPE back section.

[bhong]

I called Active and confirmed that the resonated connecting pipes you have are specifically for the equal length midpipe and must've received the wrong parts. Mine are the same as pictured on their website where the resonated part is much smaller. Not sure if that will make a huge difference on the length but I am going to attempt the install this weekend.

Originally Posted by allinon72

I have this setup and had to have the connecting pipes extended in order to reach the MPE back section.

[allinon72]

Good luck to you.

[mike@x-ph.com]

Let us know how it goes please

[allinon72]

By the way, I would do a little searching on the resonator size change before you cut anything. It's well documented they changed resonator size for sound quality reasons. And Active lists 1 connecting pipe set for both equal length and single mid pipes on their own website, they are not different.

[bhong]

Originally Posted by allinon72

By the way, I would do a little searching on the resonator size change before you cut anything. It's well documented they changed resonator size for sound quality reasons. And Active lists 1 connecting pipe set for both equal length and single mid pipes on their own website, they are not different.

Would you be able to direct me to the thread regarding the resonator size change for single midpipe for the M2C? To my knowledge, there was no resonator option early on but now they offer it with a resonator. The longer one for the equal and shorter one for the single. Included are the resonator pics from the AA website and I spoke with Alan from AA to confirm this. They must've forgot to include separate pics for the connecting pipe option.

[bhong]

Originally Posted by mike@x-ph.com

Let us know how it goes please

Will do. I got in touch with another person with this exact setup, and he was able to pair everything together with the included clamps without modification. I think the best way is to follow allinon72 since the other guy did confirm there was about 2-3 inches of space between the pipes. Worse case, I'd have to weld additional piping but no cuts should be required on the MPE or midpipe.

[fourthchirpin]

I have an MPE and the AA Single Midpipe no issues with install here. I had got the resonators but never put them on.

-Fourth

[bhong]

Thanks for your input! There are some variables to this because if the MPE was installed using factory instructions the 2 pipes will be short but the AA provided clamps may be enough to cover the gap. If you're comfortable running that way it's ok but others may want to weld additional piping so the clamps have a better seal or weld the 2 pieces together to begin with. Do you have pictures of the clamps by chance? I'll be taking some pics over the weekend and will report back with how my install went.

Originally Posted by fourthchirpin

I have an MPE and the AA Single Midpipe no issues with install here. I had got the resonators but never put them on.

-Fourth

[bhong]

Installation results:
The passenger connecting pipe was actually too long and had to be cut. Then additional piping was welded on to be able to slip inside the MPE side and clamped using the MPE clamp. Driver side came an inch or so short. Again additional piping welded on and clamped using MPE clamp. Only the ball clamps were used provided by AA. In my situation the drivers side would have been able to pair up without modification using the AA clamps but the passenger side would not have fit without cutting. I decide to weld both sides to help prevent leaks and a cleaner install. All in all, any decent muffler shop should be able to get this done for about an hours worth of labor.

[mike@x-ph.com]

Originally Posted by bhong

Installation results:
The passenger connecting pipe was actually too long and had to be cut. Then additional piping was welded on to be able to slip inside the MPE side and clamped using the MPE clamp. Driver side came an inch or so short. Again additional piping welded on and clamped using MPE clamp. Only the ball clamps were used provided by AA. In my situation the drivers side would have been able to pair up without modification using the AA clamps but the passenger side would not have fit without cutting. I decide to weld both sides to help prevent leaks and a cleaner install. All in all, any decent muffler shop should be able to get this done for about an hours worth of labor.

[bhong]

Attached are some pictures of the install/finished product. 1st pic shows we had to cut about 2 inches to leave enough gap to weld piping that can slip inside the MPE. It would not have been a direct fit as the piping was overlapping. 4th pic shows the gap was just about perfect. We could've gotten away with the AA clamps but again, welded to ensure a better seal.

[allinon72]

You made the right choice - here's what the previous owner of my car tried to do to avoid extending the connecting pipes (non-res pipes)...as you can see it turned out to be a leaky mess. I went in and fixed everything with the extended resonated pipes posted above.

[bhong]

I feel much better about it with the extended pipes welded and clamped. Now I have to locate this one rattle . Made sure there was plenty of clearance for the hangers, heat shields, brace, diff carrier, and diffuser. Also fit new gaskets for the downpipe connection and still have a rattle. There was mention of a heat shield bolt above the mid pipe that's hidden which I thought had plenty of clearance but will probably get that shaved down this weekend.

Please share if anyone had the same experience and if you found a resolution. It's a lower frequency rattle/vibration coming from directly below the shifter area, almost like a grinding. It's hard to replicate but happens when everything is warm, low rpm, higher load situations and not speed dependent. It seems to happen more when at an angle or while in a turn.