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      11-29-2021, 10:52 AM   #1
methkingM2C
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Anyone on here with an DCT TRANSMISSION and ZERO CATs downpipe/exhaust able to give their remarks or video footage regarding the 1-2k rpm rattle drone rasp issue?

I've tried:
- Catless dp + AA EL res & non-res midpipe (small and large res tried both) has a disgusting rasp scream @ 1-3k rpm (10/10 loud rasp)
- Catless dp + secondary cat delete sounds kinda rasp @ 1-2k rpm (4/10 loud rasp)
- Catless dp + stock exhaust sounds great but a bit quiet. (0/10 loud rasp)

Anyone with an aftermarket exhaust or custom resonator setup that was able to take this out while get the the added power?


UPDATE: PLEASE only comment if you have a full catless setup and have tested the 1-2.5k rpm range. Catted exhaust comments should not be made here.
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      11-29-2021, 12:09 PM   #2
ment4t
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I have the full Akrapovic system with their catless DPs on a DCT. I don't have any drone, but it might be due to the different pitch of using titanium.
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      11-29-2021, 12:10 PM   #3
methkingM2C
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Quote:
Originally Posted by ment4t View Post
I have the full Akra Ti system with their catless DPs. I don't have any drone, but it might be due to the different pitch of using titanium.
Interesting. Even in the 1-2k rpm range? DCT?

If that's the case I'm all in on AKRA.
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      11-29-2021, 12:39 PM   #4
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Quote:
Originally Posted by methkingM2C View Post
Interesting. Even in the 1-2k rpm range? DCT?

If that's the case I'm all in on AKRA.
Indeed. There is a slight "rumble" around 3K with the valves open, but it's not something I would consider drone.
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      11-29-2021, 03:10 PM   #5
methkingM2C
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Quote:
Originally Posted by ment4t View Post
Quote:
Originally Posted by methkingM2C View Post
Interesting. Even in the 1-2k rpm range? DCT?

If that's the case I'm all in on AKRA.
Indeed. There is a slight "rumble" around 3K with the valves open, but it's not something I would consider drone.
Yeah my concern is that rumble. It's a raspy sharp loud scream at the low rpm… seems like the Akra does it too…

I wonder if ANYONE has made a custom resonator setup or solved this.
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      11-30-2021, 09:47 AM   #6
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No one has DCT + full catless system that sounds good in lower rpm range!?
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      11-30-2021, 08:54 PM   #7
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Quote:
Originally Posted by methkingM2C View Post
No one has DCT + full catless system that sounds good in lower rpm range!?
Dct catless dps and midpipe no drone and no rasp.
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      11-30-2021, 09:22 PM   #8
deli333
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read my post, I was having a similiar issue. I even came to the point either fit single turbo or sell the car.

4 resonators made it so damn good especially in row rpms. even at cold start, valves fully open car does not sound obnoxious. Suprisingly car now sounds the best especially in lower rpm range lol

https://f80.bimmerpost.com/forums/sh...2&postcount=15
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      11-30-2021, 09:32 PM   #9
methkingM2C
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Quote:
Originally Posted by deli333 View Post
read my post, I was having a similiar issue. I even came to the point either fit single turbo or sell the car.

4 resonators made it so damn good especially in row rpms. even at cold start, valves fully open car does not sound obnoxious. Suprisingly car now sounds the best especially in lower rpm range lol

https://f80.bimmerpost.com/forums/sh...8;postcount=15
Dude you just confirmed everything I wanted to know! Thanks!! Do you happen to have that resonator link?

I'm gonna slap the resonators where the secondary cats were. And I'll leave the oem resonator box. I do wanna change the muffler but later.
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      11-30-2021, 10:54 PM   #10
deli333
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methkingM2C

AeroTurbine TR252 Resonators

fit them right before diff or sides of the diff.

edit: they also helped smell, I would say around 30%

https://aeroexhaust.com/i-30497639-a...ter-necks.html

sound clip
https://vocaroo.com/1sjlZ0RE0W8E

Last edited by deli333; 11-30-2021 at 11:04 PM..
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      12-01-2021, 08:59 AM   #11
methkingM2C
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Quote:
Originally Posted by deli333 View Post
methkingM2C

AeroTurbine TR252 Resonators

fit them right before diff or sides of the diff.

edit: they also helped smell, I would say around 30%

https://aeroexhaust.com/i-30497639-a...ter-necks.html

sound clip
https://vocaroo.com/1sjlZ0RE0W8E
Ordered!!! Thanks

Will update on effects for catless dp, secondary cats replaced with above resonator, oem resonator untouched, stock muffler.
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      12-02-2021, 08:56 AM   #12
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I have a DCT and full catless setup using Akra DP back as well. Driving normal and even idling it sounds great. I will admit that it is utterly obnoxious with load and WOT tho. Ive grown to like the sound but have also considered adding some additional resonators somewhere as well or even swapping my VRSF DP's to the resonated ones.
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