[veenut28]

After a few years of keeping the stock exhaust, I had the AA single midpipe installed a few weeks ago. The sound is generally better, but I’ve noticed a weird drone that happens in 3rd gear at about 3500 rpm. It’s a low frequency dull vibrating sound that’s fairly unpleasant. Interestingly it’s not as notable in 1st or 2nd gear at higher rpm’s.

I was able to take a close look at the installed midpipe and it doesn’t look like there’s any leaks. I don’t see any part of the exhaust contacting the chassis or frame. I did notice that the resonators on the connecting pipes are VERY close together- is it possible that they’re achieving some weird resonance and vibrating together at that rpm?

I’m thinking about swapping out the resonated connecting pipes for the straight ones. Anyone have any other thoughts or experience with drone after installing the AA single?

[Twonice2485]

I noticed some drone in sport+ mode in 6th gear at around 3-3.5k rpm’s, my set up was arm resonated catless downpipes, AA Single non resonated midpipe, and stock muffler.

[mike@x-ph.com]

The midpipe should not cause any drone; I recommend you double-check the installation and ensure the pipe is not hitting the brace.

[veenut28]

Originally Posted by mike@x-ph.com

The midpipe should not cause any drone; I recommend you double-check the installation and ensure the pipe is not hitting the brace.

Will do. It didn’t seem like it when I took a look before but I’ll check again. Do you think it’s possible the resonated connecting pipes might be responsible if they’re too close? I ordered a set of the straight connectors from you all since I figured that’s an easy swap that might help.

[Rumbloki]

I ran the AA single, non-res, for several months before adding the AA axle-back. Never experienced any drone.

Keep in mind, the pipes will expand and may cause contact that you don't see when cold. Does the sound come on after the car has warmed up a bit?

[mike@x-ph.com]

Originally Posted by veenut28

Will do. It didn't seem like it when I took a look before but I'll check again. Do you think it's possible the resonated connecting pipes might be responsible if they're too close? I ordered a set of the straight connectors from you all since I figured that's an easy swap that might help.

I don't think that's the cause; please note that the midpipe might not hit the brace of the car, but if it's too close, once the vehicle is on, the midpipe will expand/vibrate, which might be the cause of the drone.

Make sure you have enough clearance to avoid it hitting even with the car on.

I had the same issue, by the way, with my M4. Install looked fine, but as soon as I started driving, I heard a drone, I had to readjust the installation and never had an issue after

[veenut28]

Originally Posted by Rumbloki

I ran the AA single, non-res, for several months before adding the AA axle-back. Never experienced any drone.

Keep in mind, the pipes will expand and may cause contact that you don't see when cold. Does the sound come on after the car has warmed up a bit?

Yes, but I’m also keeping revs below 3k until the engine warms and the drone doesn’t come on until 3.5k so hard to say if it’s due to the pipes being warm.

I think I’ll switch out to the non resonated connectors and see if that helps.

[Twonice2485]

Originally Posted by veenut28

Yes, but I’m also keeping revs below 3k until the engine warms and the drone doesn’t come on until 3.5k so hard to say if it’s due to the pipes being warm.

I think I’ll switch out to the non resonated connectors and see if that helps.

If you’re interested in doing a trade with some cash on your end for an AA EQ midpipe please send me a Pm.

[veenut28]

Originally Posted by mike@x-ph.com

I don't think that's the cause; please note that the midpipe might not hit the brace of the car, but if it's too close, once the vehicle is on, the midpipe will expand/vibrate, which might be the cause of the drone.

Make sure you have enough clearance to avoid it hitting even with the car on.

I had the same issue, by the way, with my M4. Install looked fine, but as soon as I started driving, I heard a drone, I had to readjust the installation and never had an issue after

As an update, I was able to take a look under the car this weekend. I didn’t see any areas where the exhaust is close to touching the frame. It looks like there’s at least 3/4” clearance between the midpipe and the AA brace as well so I don’t think that’s it. The resonators on the connecting pipes are very close, maybe 1/8” so I really am wondering if that’s the issue.

Mike, I ordered the straight connecting pipes on 12/18 but am still waiting for shipment. Is that just typical wait time for the holidays? I can PM up with the order number.

Thanks for the advice all!

[mike@x-ph.com]

Originally Posted by veenut28

As an update, I was able to take a look under the car this weekend. I didn’t see any areas where the exhaust is close to touching the frame. It looks like there’s at least 3/4” clearance between the midpipe and the AA brace as well so I don’t think that’s it. The resonators on the connecting pipes are very close, maybe 1/8” so I really am wondering if that’s the issue.

Mike, I ordered the straight connecting pipes on 12/18 but am still waiting for shipment. Is that just typical wait time for the holidays? I can PM up with the order number.

Thanks for the advice all!

Active is closed the last two weeks of the year; they just got back, all orders will be shipping this week and next week

Please DM me here or email support@x-ph.com for order updates; I almost missed your post here.

[Twonice2485]

Originally Posted by veenut28

As an update, I was able to take a look under the car this weekend. I didn’t see any areas where the exhaust is close to touching the frame. It looks like there’s at least 3/4” clearance between the midpipe and the AA brace as well so I don’t think that’s it. The resonators on the connecting pipes are very close, maybe 1/8” so I really am wondering if that’s the issue.

Mike, I ordered the straight connecting pipes on 12/18 but am still waiting for shipment. Is that just typical wait time for the holidays? I can PM up with the order number.

Thanks for the advice all!

I had Arm resonated DP’s, AA single non-resonated, stock muffler and still had drone on the highway in sports+ mode (only), I never used sport mode so idk about that mode having drone, efficient was quiet like stock

[2020m2c]

veenut28 how’d you make out? I have AA catless dp, AA single mid and Remus race and no drone. Wondering what you found as the cause of yours?

[veenut28]

Originally Posted by 2020m2c

veenut28 how’d you make out? I have AA catless dp, AA single mid and Remus race and no drone. Wondering what you found as the cause of yours?

I think it was the resonated AB connecting pipes that were causing some vibration at certain frequencies. I swapped them out for the non-resonated pipes and it is MUCH better now. There’s still a resonance that happens in the cabin in 3rd gear at 3500+ RPM, but it’s not intolerable anymore. I might just be overly sensitive to that tone. I don’t think it was an installation issue.

All’s well that ends well. The single midpipe really changes the tone. Love it.

[2020m2c]

Originally Posted by veenut28

All’s well that ends well. The single midpipe really changes the tone. Love it.

Good to hear! I sold my EL mids. Single mid is where it’s at if you’re going catless and tuned. Sounds like a German muscle car now.
Also turned off the fake burbles and it’s even better! If I wanted a fart can boy racer I’d buy a k swap civic haha.

[Chris N]

Originally Posted by 2020m2c

Also turned off the fake burbles and it’s even better! If I wanted a fart can boy racer I’d buy a k swap civic haha.

How difficult is it to tune the bubbles completely off?

[CoffeeLife]

Originally Posted by Chris N

How difficult is it to tune the bubbles completely off?

Easy.
Download bimmerlink.

Connect to an ObdII adapter for your car.

Turn “sound tuning” to Off

- Done

Stays in memory and you can always turn it back on.

[Chris N]

Originally Posted by CoffeeLife

Easy.
Download bimmerlink.

Connect to an ObdII adapter for your car.

Turn “sound tuning” to Off

- Done

Stays in memory and you can always turn it back on.

THANK YOU!

[2020m2c]

Originally Posted by Chris N

How difficult is it to tune the bubbles completely off?

If you mean the fake ASD coming from the speakers in the car — I used Bimmercode.

If you mean the fake burbles when you lift off the throttle (yes, they are artificially induced sound effects, not sounds made because the S55 is carbureted like a Harley) then that is done with BM3 as part of the tune.