Another exhaust drone question

[The_Ryan]

I currently have a MAPerformance cat-back that looks and sounds really nice, exactly how I want from the outside. Unfortunately I've had this booming drone when I accelerate or am off throttle between 3200-3800 RPM, and it's killing me. The whole cabin resonates and it feels like my head is in a vice. They're CS said it's just the way the engine is and the fact that it's a hatch and that most louder catbacks will do the same.

I had my doubts on this because my friend's r53 mini is also a hatch without a cover and there is no drone at all, just a nice clean exhaust note. But I thought I'd at least double check with the community here if that's truly the case. I was curious if there's anything I may have done during install or if there's something else that I can do to reduce this drone. I've checked all the joints and there's no leaks and all the bolts feel plenty tight.

So for those with MAPperformance exausts or other systems, do you have this issue as well? I'd like to gauge if every exhaust truly has this problem, or if it's just me some how. If it's not a problem with every exhaust, then which ones do have this drone. I don't want to drop the money on another exhaust only to continue driving this car in pain.

So I was also eyeing a Milltek non-res cat-back as a replacement in particular, as I've had good experience with them on previous cars, so if there is any insight on those particular exhaust, that'd be great.

Thanks,

 

[kivnul]

ThermalR&D's 3" system has the least drone of them all from what I have gathered. Unsure about the MAPerformance one specifically.

 

[Chaski]

I have a Thermal- and it has very little harmonic dron. There is a small amount that is noticeable when the seats are down.

 

[Clint Beastwood]

I currently have a MAPerformance cat-back that looks and sounds really nice, exactly how I want from the outside. Unfortunately I've had this booming drone when I accelerate or am off throttle between 3200-3800 RPM, and it's killing me. The whole cabin resonates and it feels like my head is in a vice. They're CS said it's just the way the engine is and the fact that it's a hatch and that most louder catbacks will do the same.

I had my doubts on this because my friend's r53 mini is also a hatch without a cover and there is no drone at all, just a nice clean exhaust note. But I thought I'd at least double check with the community here if that's truly the case. I was curious if there's anything I may have done during install or if there's something else that I can do to reduce this drone. I've checked all the joints and there's no leaks and all the bolts feel plenty tight.

So for those with MAPperformance exausts or other systems, do you have this issue as well? I'd like to gauge if every exhaust truly has this problem, or if it's just me some how. If it's not a problem with every exhaust, then which ones do have this drone. I don't want to drop the money on another exhaust only to continue driving this car in pain.

So I was also eyeing a Milltek non-res cat-back as a replacement in particular, as I've had good experience with them on previous cars, so if there is any insight on those particular exhaust, that'd be great.

Thanks,

I haven’t found any info about the Milltek staying they do anything to specifically target the frequencies that drone, that doesn’t mean they don’t, but thermal specifically states they use a quarter wave resonator in the rear that is calculated for just that purpose.

 

[The_Ryan]

Yeah the reason I was looking at milltek over thermal is that 1) I didn't really like the sound of the thermal, and 2) it seems a bit louder than I'd like. My neighbor still likes me 3) the price at the moment, if I hadn't already spent the money on one exhaust.

edit: there is something somewhere stating that Milltek did take the effort to address any sort of drone. however that was said about the MAP exhaust as well, so I'm looking to see if anyone in particular has experience with that on their Milltek or other exhaust systems

 

[Clint Beastwood]

Yeah I saw marketing claims but no engineering data on the Milltek. Not knocking it, I just don’t know.

 

[The_Ryan]

bumping to see if anyone else has any input with their milltek or other exhaust

 

[Clint Beastwood]

bumping to see if anyone else has any input with their milltek or other exhaust

Unfortunately drone is all subjective without instrumented testing and nobody really does it. Some good quality interior video with the windows up would give us a source file to pull audio drive from if anyone has the ability to do so.

 

[scooter123]

I have a Cobb 2.5" catback and there is a bit of a boom between 3200-4000 rpm with the rear seats in the up position and the package shelf in place. Fold the seats down and remove the package shelf and it's a LOT louder, probably loud enough to cause some hearing loss in a long term exposure. Since I don't normally cruise in this RPM band it really doesn't bother me.

 

[antarctica24]

ThermalR&D's 3" system has the least drone of them all from what I have gathered. Unsure about the MAPerformance one specifically.

Yeah, Ive had 5 different exhaust systems on my car, because everyone claims there's is better and has no drone which is BS. The Thermal R & D has the least amount of drone of all the ones I had, including the CP-E, and the Borla, and the MAP.

 

[CarGuy]

Yeah, Ive had 5 different exhaust systems on my car, because everyone claims there's is better and has no drone which is BS. The Thermal R & D has the least amount of drone of all the ones I had, including the CP-E, and the Borla, and the MAP.

What about the Mountune?

Sent from my SM-N950U using Tapatalk

 

[AZSP33D]

Is drone reduced at all by a thremal wrap for any section of the exhaust pipe? The Thermal R&D is a heavy sucker for sure BTW.

 

[antarctica24]

Is drone reduced at all by a thremal wrap for any section of the exhaust pipe? The Thermal R&D is a heavy sucker for sure BTW.

The drone noise is coming from the lack of resonator and design of muffler. It’s the combination that makes it work or not work.

 

[antarctica24]

What about the Mountune?

Sent from my SM-N950U using Tapatalk

That would be one I didn’t try, but you can look at the muffler and tell if it will have drone or not. If there is no resonator there will be drone 100%. If there is a resonator it will depend on the resonator design and muffler design. It has to do with wave form acoustics and sound wave cancelling. Which oddly enough the cpe is supposed to resolve but doesn’t. Which ever one you pick ask the company if their exhaust has a drone inside the cabin about 3k? If they do, then ask them if you buy it and it does will that take it back? If they say no then they were lying in the first place. Ooorrrr. Trust me I have spent more on exhausts systems than most hunting down how to get rid of that drone and the only one that comes close is the thermal r &d.

 

[M-Sport fan]

^^^The CP-E only has a resonator and a branched Helmhotz chamber, so even if one added a substantial muffler to that system, that drone/buzzing/booming would STILL be there?

 

[Clint Beastwood]

Is drone reduced at all by a thremal wrap for any section of the exhaust pipe? The Thermal R&D is a heavy sucker for sure BTW.

no it will not, not substantively. The resonance in the fist is a product of the 106.67hz wave created by the long straight section of pipe down the middle of the car. You need to cancel it with an inverse wave, which as far as I know only thermal does.