[atruong247]

Originally Posted by BMW DIY Guy

I have confirmation on pipe wall thickness, and the AA's are actually thicker than OEM, with caliper measurement.

OEM is 1.3mm
AA is 1.52mm

So I understand your concern on this point at least, but when measuring that is not the case.

Ouch. I admit defeat. Thanks for finding these numbers.

Perhaps it's the blind belief that since I am always hearing so many vibrations, I am to assume the build quality is cheap. Appreciate you clearing something up.

[BMW DIY Guy]

Originally Posted by atruong247

Ouch. I admit defeat. Thanks for finding these numbers.

Perhaps it's the blind belief that since I am always hearing so many vibrations, I am to assume the build quality is cheap. Appreciate you clearing something up.

Happy to help, and also wish you were closer! If you have vibration, then there HAS to be a fitment issue at some point. If you were closer, I would happily take a look at it for you and see if we can find it, like I did on my initial single channel install. I had a single bolt that would contact at only the EXACT right (or wrong as it were) vibration. Once I fixed that, zero issues.

There shouldn't be any vibration and really the only source for that has to be something regarding fitment.

Happy to help if you were any closer..

[scarygary]

Originally Posted by BMW DIY Guy

Happy to help, and also wish you were closer! If you have vibration, then there HAS to be a fitment issue at some point. If you were closer, I would happily take a look at it for you and see if we can find it, like I did on my initial single channel install. I had a single bolt that would contact at only the EXACT right (or wrong as it were) vibration. Once I fixed that, zero issues.

There shouldn't be any vibration and really the only source for that has to be something regarding fitment.

Happy to help if you were any closer..

How did your bolts hold up? On the second time adjusting I realized the threads were screwed up on a couple of mine

[BMW DIY Guy]

Originally Posted by scarygary

How did your bolts hold up? On the second time adjusting I realized the threads were screwed up on a couple of mine

No issues thus far, cranked down with good spacing, really tight to avoid anything moving or working loose.

[atruong247]

Originally Posted by BMW DIY Guy

Happy to help, and also wish you were closer! If you have vibration, then there HAS to be a fitment issue at some point. If you were closer, I would happily take a look at it for you and see if we can find it, like I did on my initial single channel install. I had a single bolt that would contact at only the EXACT right (or wrong as it were) vibration. Once I fixed that, zero issues.

There shouldn't be any vibration and really the only source for that has to be something regarding fitment.

Happy to help if you were any closer..

Appreciate the gesture. Yeah, it'd be great to be able to get under the car at any time. Last time I got an oil change, I was able to tinker with the midpipe clamps. Swapped the AA provided clamps to some Evil Energy clamps from Amazon. Fixed a good amount of issues.

It didn't seem like a fitment problem. clearances were checked and the midpipe itself was solid and not rocking around. Can't say for sure if it's actually hitting something unless it's on and revving. The thing is, it's the shaking sound that the pipes produce that maybe gives off the illusion it's not solid. Perhaps it's the connection of the midpipe to the stock box. clamps can only do so much, right? I'm also inclined to believe the stock box is producing some vibration sounds too. It could also be that these sounds are normal and I'm just expecting too much.

The stock box is currently just a placeholder for when I get the meisterschaft titanium exhaust fitted. Definitely will be finding some method of welding the midpipe to the titanium exhaust.

[///MPECABL]

[scarygary]

Originally Posted by scarygary

Mine at the connection you're referring to, the axleback pipes are touching the connector pipes. So I guess that could be it too. I was thinking it was at the spherical joints by the resonators, cant imagine those clamps tight enough to keep that joint from vibrating at some point. Also the thread on bolts at the torca clamp screwed up on mine, probably from over tightening.

this thing could be a solution if its the ball flange vibrating

https://autoplicity.com/10755112-ap-...lange-2-716-id

[mrcheezle19]

So I ran just the AA non res midpipe for 4 months and a slight vibration which I attributed to a less than stellar install. I also had a decent amount of rasp on start up and when in 1st gear so I was hesistant to get the AA axle back. I finally went for it and added the axle back and WOW! The shop adjusted the midpipe so no more vibration against the heat shield and there is absolutely no rasp and zero drone which I was amazed by. If anyone with just the midpipe has been hesistant I would definately say go for it.

[BMW DIY Guy]

Originally Posted by mrcheezle19

So I ran just the AA non res midpipe for 4 months and a slight vibration which I attributed to a less than stellar install. I also had a decent amount of rasp on start up and when in 1st gear so I was hesistant to get the AA axle back. I finally went for it and added the axle back and WOW! The shop adjusted the midpipe so no more vibration against the heat shield and there is absolutely no rasp and zero drone which I was amazed by. If anyone with just the midpipe has been hesistant I would definately say go for it.

I want to add that myself!

[M_Squared]

Originally Posted by BMW DIY Guy

The video isn't up yet, but will be soon. I am running (now) AA DPs, EL mid with resonated ABs and stock (non M Performance) exhaust.

I am working on an fully comprehensive comparison video for sound changes with midpipes.

Video will be the following configurations.

Component combinations:
1. Full stock OEM - downpipes, midpipe and exhaust

2. Stock downpipes, Active single channel midpipe with and without resonated AB pipes, and stock exhaust.

3. Active downpipes, Active single channel midpipe with and without resonated AB pipes, and stock exhaust.

4. Active downpipes, Active EL midpipe with resonated AB pipes, and stock exhaust.

I'm glad I found this thread. I've been searching to find the right downpipe to pair with the AA EL resonated mid. I did the install myself and the only issue I had was the muffler contacting the diffuser while driving. I end up cutting about 5mm more of the factory pipe to allow more clearance and made sure the pipes were pressed closely together. This has resolve this issue and I have no complaints... other than wanting to hear more turbo noises

Most of the time I let the car go through the cold start phase before driving off. I personally do not hear rasp

All the videos I've found so far, catless DP and AA EL for M2C, just does not sound good too me, too much rasp. Could be install error or brand of DP

My setup, 6mt, factory DP, AA EL resonated, factory exhaust

What are your thoughts with a resonated DP such as the ones from AR?

[BMW DIY Guy]

Originally Posted by M_Squared

I'm glad I found this thread. I've been searching to find the right downpipe to pair with the AA EL resonated mid. I did the install myself and the only issue I had was the muffler contacting the diffuser while driving. I end up cutting about 5mm more of the factory pipe to allow more clearance and made sure the pipes were pressed closely together. This has resolve this issue and I have no complaints... other than wanting to hear more turbo noises

Most of the time I let the car go through the cold start phase before driving off. I personally do not hear rasp

All the videos I've found so far, catless DP and AA EL for M2C, just does not sound good too me, too much rasp. Could be install error or brand of DP

My setup, 6mt, factory DP, AA EL resonated, factory exhaust

What are your thoughts with a resonated DP such as the ones from AR?

my big comparison video goes up in about 10 days! 8)

[JamesinIT]

I am glad I am not the only one with this concern.
2020 M2C
Stock DP
AA EL Non Resonated
AA Axleback

During WOT and most times sounds great. But if I happen to have the car in sport, but have the transmission in the smoothest setting, part throttle sounds terrible, like fart can Civic terrible. Part throttle in efficient sounds like this nearly all the time. It is awful.

I eliminated all the vibrations, as many other stated this was primarily alignment or heatshield related. Once I got that right, then I noticed the rasp more. (Sounds identical to the OP's first video).

I have reduced this some:

1. I found that the small (unnecessary in my opinion)brace between the two exhaust exit pipe had broken on the passenger side, but it was next to impossible to see. I pried it far enough away from the side that had broken, and it eliminated some of the noise.

2. The torcas they supply are no able to really prevent any form of exhaust leak as evidenced by the sound and drips on the floor). I ended up snapping off a bolt while trying to get it tighter. Replaced bolts and used exhaust sealant. That reduced the exhaust leak.

3. Next to address; the ball clamps. These do leak as evidence by a slight exhaust leak sound, and the water/carbon drops on the floor. I'm not sure why they chose this option to join these pipes. I need to measure the bolts and older some grade 8 hardware before I attempt this. I'll also use the exhaust putty to help prevent this as well.

[Finz]

Originally Posted by JamesinIT

I am glad I am not the only one with this concern.
2020 M2C
Stock DP
AA EL Non Resonated
AA Axleback

During WOT and most times sounds great. But if I happen to have the car in sport, but have the transmission in the smoothest setting, part throttle sounds terrible, like fart can Civic terrible. Part throttle in efficient sounds like this nearly all the time. It is awful.

I eliminated all the vibrations, as many other stated this was primarily alignment or heatshield related. Once I got that right, then I noticed the rasp more. (Sounds identical to the OP's first video).

I have reduced this some:

1. I found that the small (unnecessary in my opinion)brace between the two exhaust exit pipe had broken on the passenger side, but it was next to impossible to see. I pried it far enough away from the side that had broken, and it eliminated some of the noise.

2. The torcas they supply are no able to really prevent any form of exhaust leak as evidenced by the sound and drips on the floor). I ended up snapping off a bolt while trying to get it tighter. Replaced bolts and used exhaust sealant. That reduced the exhaust leak.

3. Next to address; the ball clamps. These do leak as evidence by a slight exhaust leak sound, and the water/carbon drops on the floor. I'm not sure why they chose this option to join these pipes. I need to measure the bolts and older some grade 8 hardware before I attempt this. I'll also use the exhaust putty to help prevent this as well.

Do you have DCT? I have same setup with 6 MT and once warmed up I think it is very good. I only get bad sounds when the pipes are cold.

[Navy Davy]

Originally Posted by BMW DIY Guy

my big comparison video goes up in about 10 days! 8)

Steph, your dps sounded great in your first vid. I can't wait to see how it sounds with the AA muffler. I wish there were more videos out there of dps that work with the AA EL.

[BMW DIY Guy]

Originally Posted by Navy Davy

Steph, your dps sounded great in your first vid. I can't wait to see how it sounds with the AA muffler. I wish there were more videos out there of dps that work with the AA EL.

Me too me too.. looks like about a week for shipping then can get serious about the install.

[Navy Davy]

Originally Posted by BMW DIY Guy

Me too me too.. looks like about a week for shipping then can get serious about the install.

Perfect way to close out the year!

[DirtyD_M2C]

Originally Posted by BMW DIY Guy

Hey yall..

So I will have full video up soon for the EL install, plus driving comparisons between OEM, Active single channel (both resonated and non resonated) and also new to me the EL resonated midpipe.

I have been deep diving into all of the threads on the reported problem of 'rasp' and after reading probably 100+ comments, I am honestly confused. I watched and listed to several EL cold start videos and as the RPM settles, on several I could hear what sounded like metal on metal vibration. (see my point 1 below)

This isn't to say anyone isn't hearing what they are hearing, but really pondering the variables here.

Here is my current config:
AA *cough mumble* [redacted] *cough* DPs
AA EL midpipe
Stock OEM non M performance exhaust

First cold start.. zero rasp, or what I would call that.
First drive out with no issues, and about 2 hours in the car of solid drive time with varied speeds, conditions, lots and lots of shifting.

I have been pondering this a LOT both with the single channel mid and now the EL midpipe.

First, for clarity, I have cold start turned off in my tune and have the GTS roar at startup turned on.

My thoughts are:

1. Install problem? Are folks confusing a metallic rattle/vibration at certain RPMs because they have a fitment issue? In my single channel install, on first drive I had a vibration because the clearance off of a bolt head was fine sitting still but under one certain RPM the pipe would vibrate enough to hit it. Found that immediately when driving, found the issue and fixed it.

2. Install problem at the connection between DP and midpipe? I say this simply because I ran into someone recently with an F80 that DIDN'T have the locking plate at the DP/midpipe connection (WHAT?!?!) and said it had never been there. I could see where his pipes were hitting each other. Granted, very likely not common whatsoever, but a thought. Same thing with those conical gaskets at the end of the DPs.. I find they are often missing if I am working on a car that already has an aftermarket exhaust/midpipe on it. I think most people miss them, forget about them or don't realize they are there when they come out with the OEM midpipe.

3. Is there any pattern to the rasp in combination of other specific hardware? So for example.. X brand/type midpipes with Y brand (oem, aftermarket, whatever) exhaust and Z downpipes? Could there be a pattern of this happening?

4. Related to tuning? Also in trying to narrow variables, what tune are the various folks running and in what modes and settings? Considering how much higher tunes can spin up the turbos over stock pressure, is there something related to exhaust and turbo pressure coming back down the pipes? If someone IS tuned (very likely) and is complaining about a bad rasp, if you flash back to stock to test does it go away? If it doesn't, then not related to the tune, if it does go away entirely then something about their tune is doing it. Then they can try stock tune images like I can on my M2C.. so try stock, then the stock CS tune, then the stage 1, then stage 2 and custom tune and so on.

Yeah, that is a ton of testing, but also would narrow variables a ton.

5. Are folks confusing rasp and burbles? This is unlikely, but worth asking. If you have a tune on the car, I would turn burbles OFF entirely and test again? Do you still get a "rasp" sound, and exactly how and when? Under acceleration, or when you lift your foot (mistaken burbles?) and what RPMs?

This is all just off the top of my head.. there HAS to be a pattern here.

I don't envy trying to chase this down as there are dozens of variables involved from physical install, to tune, driving modes, what options are enabled and more.

I did the initial cold start after install, then revs in efficient mode, then sport + everything open and it sounded great the entire time.

So far, I am VERY pleased.. I liked the single channel midpipe and already like the EL even more.

Originally Posted by BMW DIY Guy

Hey yall..

So I will have full video up soon for the EL install, plus driving comparisons between OEM, Active single channel (both resonated and non resonated) and also new to me the EL resonated midpipe.

I have been deep diving into all of the threads on the reported problem of 'rasp' and after reading probably 100+ comments, I am honestly confused. I watched and listed to several EL cold start videos and as the RPM settles, on several I could hear what sounded like metal on metal vibration. (see my point 1 below)

This isn't to say anyone isn't hearing what they are hearing, but really pondering the variables here.

Here is my current config:
AA *cough mumble* [redacted] *cough* DPs
AA EL midpipe
Stock OEM non M performance exhaust

First cold start.. zero rasp, or what I would call that.
First drive out with no issues, and about 2 hours in the car of solid drive time with varied speeds, conditions, lots and lots of shifting.

I have been pondering this a LOT both with the single channel mid and now the EL midpipe.

First, for clarity, I have cold start turned off in my tune and have the GTS roar at startup turned on.

My thoughts are:

1. Install problem? Are folks confusing a metallic rattle/vibration at certain RPMs because they have a fitment issue? In my single channel install, on first drive I had a vibration because the clearance off of a bolt head was fine sitting still but under one certain RPM the pipe would vibrate enough to hit it. Found that immediately when driving, found the issue and fixed it.

2. Install problem at the connection between DP and midpipe? I say this simply because I ran into someone recently with an F80 that DIDN'T have the locking plate at the DP/midpipe connection (WHAT?!?!) and said it had never been there. I could see where his pipes were hitting each other. Granted, very likely not common whatsoever, but a thought. Same thing with those conical gaskets at the end of the DPs.. I find they are often missing if I am working on a car that already has an aftermarket exhaust/midpipe on it. I think most people miss them, forget about them or don't realize they are there when they come out with the OEM midpipe.

3. Is there any pattern to the rasp in combination of other specific hardware? So for example.. X brand/type midpipes with Y brand (oem, aftermarket, whatever) exhaust and Z downpipes? Could there be a pattern of this happening?

4. Related to tuning? Also in trying to narrow variables, what tune are the various folks running and in what modes and settings? Considering how much higher tunes can spin up the turbos over stock pressure, is there something related to exhaust and turbo pressure coming back down the pipes? If someone IS tuned (very likely) and is complaining about a bad rasp, if you flash back to stock to test does it go away? If it doesn't, then not related to the tune, if it does go away entirely then something about their tune is doing it. Then they can try stock tune images like I can on my M2C.. so try stock, then the stock CS tune, then the stage 1, then stage 2 and custom tune and so on.

Yeah, that is a ton of testing, but also would narrow variables a ton.

5. Are folks confusing rasp and burbles? This is unlikely, but worth asking. If you have a tune on the car, I would turn burbles OFF entirely and test again? Do you still get a "rasp" sound, and exactly how and when? Under acceleration, or when you lift your foot (mistaken burbles?) and what RPMs?

This is all just off the top of my head.. there HAS to be a pattern here.

I don't envy trying to chase this down as there are dozens of variables involved from physical install, to tune, driving modes, what options are enabled and more.

I did the initial cold start after install, then revs in efficient mode, then sport + everything open and it sounded great the entire time.

So far, I am VERY pleased.. I liked the single channel midpipe and already like the EL even more.

I've run every setup, you don't like resonated?

[DirtyD_M2C]

Originally Posted by DirtyD_M2C

I've run every setup, you don't like resonated?

Originally Posted by BMW DIY Guy

Hey yall..

So I will have full video up soon for the EL install, plus driving comparisons between OEM, Active single channel (both resonated and non resonated) and also new to me the EL resonated midpipe.

I have been deep diving into all of the threads on the reported problem of 'rasp' and after reading probably 100+ comments, I am honestly confused. I watched and listed to several EL cold start videos and as the RPM settles, on several I could hear what sounded like metal on metal vibration. (see my point 1 below)

This isn't to say anyone isn't hearing what they are hearing, but really pondering the variables here.

Here is my current config:
AA *cough mumble* [redacted] *cough* DPs
AA EL midpipe
Stock OEM non M performance exhaust

First cold start.. zero rasp, or what I would call that.
First drive out with no issues, and about 2 hours in the car of solid drive time with varied speeds, conditions, lots and lots of shifting.

I have been pondering this a LOT both with the single channel mid and now the EL midpipe.

First, for clarity, I have cold start turned off in my tune and have the GTS roar at startup turned on.

My thoughts are:

1. Install problem? Are folks confusing a metallic rattle/vibration at certain RPMs because they have a fitment issue? In my single channel install, on first drive I had a vibration because the clearance off of a bolt head was fine sitting still but under one certain RPM the pipe would vibrate enough to hit it. Found that immediately when driving, found the issue and fixed it.

2. Install problem at the connection between DP and midpipe? I say this simply because I ran into someone recently with an F80 that DIDN'T have the locking plate at the DP/midpipe connection (WHAT?!?!) and said it had never been there. I could see where his pipes were hitting each other. Granted, very likely not common whatsoever, but a thought. Same thing with those conical gaskets at the end of the DPs.. I find they are often missing if I am working on a car that already has an aftermarket exhaust/midpipe on it. I think most people miss them, forget about them or don't realize they are there when they come out with the OEM midpipe.

3. Is there any pattern to the rasp in combination of other specific hardware? So for example.. X brand/type midpipes with Y brand (oem, aftermarket, whatever) exhaust and Z downpipes? Could there be a pattern of this happening?

4. Related to tuning? Also in trying to narrow variables, what tune are the various folks running and in what modes and settings? Considering how much higher tunes can spin up the turbos over stock pressure, is there something related to exhaust and turbo pressure coming back down the pipes? If someone IS tuned (very likely) and is complaining about a bad rasp, if you flash back to stock to test does it go away? If it doesn't, then not related to the tune, if it does go away entirely then something about their tune is doing it. Then they can try stock tune images like I can on my M2C.. so try stock, then the stock CS tune, then the stage 1, then stage 2 and custom tune and so on.

Yeah, that is a ton of testing, but also would narrow variables a ton.

5. Are folks confusing rasp and burbles? This is unlikely, but worth asking. If you have a tune on the car, I would turn burbles OFF entirely and test again? Do you still get a "rasp" sound, and exactly how and when? Under acceleration, or when you lift your foot (mistaken burbles?) and what RPMs?

This is all just off the top of my head.. there HAS to be a pattern here.

I don't envy trying to chase this down as there are dozens of variables involved from physical install, to tune, driving modes, what options are enabled and more.

I did the initial cold start after install, then revs in efficient mode, then sport + everything open and it sounded great the entire time.

So far, I am VERY pleased.. I liked the single channel midpipe and already like the EL even more.

I don't like either EL option, Signature system where it's at.

[JamesinIT]

Originally Posted by Finz

Do you have DCT? I have same setup with 6 MT and once warmed up I think it is very good. I only get bad sounds when the pipes are cold.

I do have a DCT, it sounds fine at most conditions other than part throttle for the most part.

[PHX102]

Originally Posted by DirtyD_M2C

I don't like either EL option, Signature system where it's at.

What do you like better about the signature system? There is a used one local to me and I'm thinking about pulling the trigger but haven't been able to listen to it in person. Do you have burbles turned on or off?

[usc335]

Just another data point. I recently installed the Active Autowerke Equal Length Midpipe (Resonated) and Valved Rear Axle-Back Exhaust with stock downpipes on my M2C 6MT and have zero rasp or rattle under cold, warming up, or fully warmed up conditions. This exhaust combo sounds amazing!

[BMW DIY Guy]

Sorry about the delay on install DIY and subsequent comparison video: Damn covid finally got me last week, so really haven't done a thing in almost a week.

I will have everything posted up asap.