[Info@mad-us.com]

Originally Posted by cuztom15

Info@mad-us.com Hey I emailed you 48hrs ago and have not received a response. Please check your inbox. Thank you.

Hey, I don’t have any messages from you I just double checked.

Can you send it again or send your question in an email info@mad-us.com

[wrh3]

Originally Posted by cuztom15

Since this thread has had a lot of traction, I wanted to know if others saw this fitment issue with the rear midpipe section?

See 1st 2 photos.

Also anyone had any clearance issues with the first clamp on the midpipe just after the transmission bolt mount? See 3rd photo. My front section hits the heat shield stud above it in first when taking off because its so close.

Great kit, solid and pretty, but terrible fitment and minor leaks were a real bear to tackle. Still have one on the cross section.

Same here with tight fit around diff/mount, but for me a Milltek single midpipe/xpipe combo with MAD rear section.

[_slo58]

Originally Posted by MASHCT

The inner tube is flush with the end of the outlet pipe. I was going to install them in the exhaust pipe before the muffler, but then they'd be a bitch to remove for track days, or if I want to take them out for videos/cars and coffee/meets.

They are the 3 disk, 3" inserts. Measure the outer diameter of your exhaust pipe (wherever you plan to insert them) and then you will know what diameter insert to get. The MAD exhaust OD of the tailpipe is 3".

According to car chemistry the packing material reduces sound a further 2-4 decibels. Just an FYI.

Thanks for thread, I have recently installed the MAD axleback on my X3M and noticed an increase in 2k RPM drone. I have catless DPs and the MAD resonated single midpipe.

My goal is to reduce the drone only when valves are fully closed (i.e., for extended highway cruising). From your picture, it looks like you installed the inserts on the muffler pipes and not the outer valved pipes. Does this then only reduce the exhaust note when valves are closed without affecting the flow/sound when the valves are fully open (when the muffler is bypassed)?

P.S. I am no expert on exhaust systems, so please correct me if my understanding of valved axleback exhausts is incorrect.

[Info@mad-us.com]

Originally Posted by _slow58

Thanks for thread, I have recently installed the MAD axleback on my X3M and noticed an increase in 2k RPM drone. I have catless DPs and the MAD resonated single midpipe.

My goal is to reduce the drone only when valves are fully closed (i.e., for extended highway cruising). From your picture, it looks like you installed the inserts on the muffler pipes and not the outer valved pipes. Does this then only reduce the exhaust note when valves are closed without affecting the flow/sound when the valves are fully open (when the muffler is bypassed)?

P.S. I am no expert on exhaust systems, so please correct me if my understanding of valved axleback exhausts is incorrect.

How is the drone with valves open cruising? I find that it helps and the exhaust isn't much louder at cruising rpm.

[_slo58]

Originally Posted by Info@mad-us.com

How is the drone with valves open cruising? I find that it helps and the exhaust isn't much louder at cruising rpm.

The drone is louder, but is overpowered by the sound of the exhaust when the valves are open. Valves closed is quieter when cruising but is just a bit too drony for me.

Info@mad-us.com is the diameter of the tailpipe for the X3M axleback 3in?

[Info@mad-us.com]

Originally Posted by _slow58

The drone is louder, but is overpowered by the sound of the exhaust when the valves are open. Valves closed is quieter when cruising but is just a bit too drony for me.

Info@mad-us.com is the diameter of the tailpipe for the X3M axleback 3in?

Info was emailed to you.

[MASHCT]

Originally Posted by _slow58

Thanks for thread, I have recently installed the MAD axleback on my X3M and noticed an increase in 2k RPM drone. I have catless DPs and the MAD resonated single midpipe.

My goal is to reduce the drone only when valves are fully closed (i.e., for extended highway cruising). From your picture, it looks like you installed the inserts on the muffler pipes and not the outer valved pipes. Does this then only reduce the exhaust note when valves are closed without affecting the flow/sound when the valves are fully open (when the muffler is bypassed)?

P.S. I am no expert on exhaust systems, so please correct me if my understanding of valved axleback exhausts is incorrect.

Howdy bub! Yes, I did inserts in the tailpipes. The tips will still fit with the inserts in place.

You can install them in the pipes themselves after the split & before the actual muffler box. I didn't do that because then you can't remove them if you ever want it louder & to remove the back pressure they introduce for track day (it's minor, mfg said something like 2%.)

They work for sure, and quiet it down enough to not be annoying. But trust me - it's still plenty loud! Gives it a nice growl, too. Deepens the tone some.

Let me know if you need any other info.

[sydsM2]

Originally Posted by Tumblingmirth

Well this did not go as well for me. Just had the non res mid and axel back installed. Was supposed to have the mad valve controller too but whichever supplier my shop used forgot to ship it. So that’s next week.

The drone is horrible. I had read that people have had good success with this. I need ear plugs to drive now. Don’t get me wrong. The upgraded sound and such is great. But the driving aspect for me not so much. I may try these inserts you speak of. Or have to swap back to oem. Maybe go with resonated mid.

I know this post is a year old, but I just added the MAD axle back to my existing MAD non resonated midpipe and I am experiencing the same problems you are (or were) inside the cabin. I have a bad drone from 2-3k rpm and excessive loudness. I also have the MAD valve controller and I'm hearing this with the valves fully closed, the engine in Efficient mode, and ASD turned off.

How did you ultimately fix this? Was it an installation issue? Did you replace the non resonated midpipe with the MAD resonated midpipe (which is what I'm thinking of doing as I happen to have one)? I am not able to install these exhaust parts myself and have to pay someone to do it, so I'd like to get it right on my next try.

I appreciate any guidance you can provide from your similar experience.

[Rush24/7]

Originally Posted by sydsM2

I know this post is a year old, but I just added the MAD axle back to my existing MAD non resonated midpipe and I am experiencing the same problems you are (or were) inside the cabin. I have a bad drone from 2-3k rpm and excessive loudness. I also have the MAD valve controller and I'm hearing this with the valves fully closed, the engine in Efficient mode, and ASD turned off.

How did you ultimately fix this? Was it an installation issue? Did you replace the non resonated midpipe with the MAD resonated midpipe (which is what I'm thinking of doing as I happen to have one)? I am not able to install these exhaust parts myself and have to pay someone to do it, so I'd like to get it right on my next try.

I appreciate any guidance you can provide from your similar experience.

Unfortunately, there’s no way to fix it. Different mufflers will have varying levels of drone based on design. I had a really bad drone with my IRL full catback and putting the stock muffler back on fixed it. I now have a full Fi exhaust with no drone issues, but it’s not as loud as the IRL catback.


IMO you have to compromise overall loudness if you don’t want drone. This is why so many people keep the stock axle back because it’s already as loud as you can get without introducing drone.

I suggest you put your stock muffler back on if you want to for sure get it right.

[sydsM2]

Wow, I didn’t expect that to be the case. I really like the look of the MAD axle back and would prefer not to put the stock one back if I can avoid it.

I guess the next best thing is to try and reduce the drone and excessive loudness as much as possible. To that end how much will switching back to the resonated midpipe help?

You also mentioned that your Fi exhaust does not drone. How is that happening If the stock axle back is the only way to stop the drone?

[Info@mad-us.com]

Originally Posted by sydsM2

I know this post is a year old, but I just added the MAD axle back to my existing MAD non resonated midpipe and I am experiencing the same problems you are (or were) inside the cabin. I have a bad drone from 2-3k rpm and excessive loudness. I also have the MAD valve controller and I'm hearing this with the valves fully closed, the engine in Efficient mode, and ASD turned off.

How did you ultimately fix this? Was it an installation issue? Did you replace the non resonated midpipe with the MAD resonated midpipe (which is what I'm thinking of doing as I happen to have one)? I am not able to install these exhaust parts myself and have to pay someone to do it, so I'd like to get it right on my next try.

I appreciate any guidance you can provide from your similar experience.

And with the valves open? I've had similar issues on catbacks in the past where valve open on the highway helped with drone compared to closed valve.


Resonators will help with drone but no guarantees it fully eliminates it.

[sydsM2]

Originally Posted by Info@mad-us.com

And with the valves open? I've had similar issues on catbacks in the past where valve open on the highway helped with drone compared to closed valve.


Resonators will help with drone but no guarantees it fully eliminates it.

There is minimal difference with the valves open in the 2-3k range. There is a more noticeable difference in sound, however,
4K and above.

How much will the resonated midpipe help with the drone? 50% reduction, 90% reduction, etc.? Best estimate here would be helpful.

[Info@mad-us.com]

Originally Posted by sydsM2

There is minimal difference with the valves open in the 2-3k range. There is a more noticeable difference in sound, however,
4K and above.

How much will the resonated midpipe help with the drone? 50% reduction, 90% reduction, etc.? Best estimate here would be helpful.

Total guess but I would estimate 20%? Everyone's tolerance is completely different so it's hard to put a finger on it.

[Rush24/7]

Originally Posted by sydsM2

Wow, I didn’t expect that to be the case. I really like the look of the MAD axle back and would prefer not to put the stock one back if I can avoid it.

I guess the next best thing is to try and reduce the drone and excessive loudness as much as possible. To that end how much will switching back to the resonated midpipe help?

You also mentioned that your Fi exhaust does not drone. How is that happening If the stock axle back is the only way to stop the drone?

The mufflers that don’t drone tend to be more expensive and are packed very well with internal designs that combat drone. This affects maximum loudness. My Fi exhaust doesn’t drone because it’s not louder than the stock axle back. Actually tbh I think it might even be a little quieter. Hard to say since it’s a different tone with much more bass.

If you only care about sound and volume then the stock axle back is the way to go. As loud as it gets with no drone. If you want the looks or weight reduction, there are expensive axle backs that will not drone, but they won’t be noticeably louder.

[Info@mad-us.com]

Originally Posted by Rush24/7

The mufflers that don’t drone tend to be more expensive and are packed very well with internal designs that combat drone. This affects maximum loudness. My Fi exhaust doesn’t drone because it’s not louder than the stock axle back. Actually tbh I think it might even be a little quieter. Hard to say since it’s a different tone with much more bass.

If you only care about sound and volume then the stock axle back is the way to go. As loud as it gets with no drone. If you want the looks or weight reduction, there are expensive axle backs that will not drone, but they won’t be noticeably louder.

I spent about an hour and a half driving around with the owner, testing different settings.

Personally, I wouldn’t consider it to have drone. There is a slight deeper tone right around 2,000 RPM, but it quickly goes away as you get past that range.

Having been in cars with actual drone like an E9X M3 with certain catbacks where you can’t even hold a conversation and it feels overwhelming this is nowhere near that.

I’d rate the MAD catback at about a 2 out of 10 on the drone scale.

The only thing we didn’t get to test was a long highway run at a constant speed, so I can only speak to city driving based on my experience.