11-02-2020, 06:59 PM | #1 |
New Member
8
Rep 25
Posts |
1M drone fix with mid pipe swap?
Hello to all! I purchased a 1M a few weeks ago and love it.
I think the stock exhaust system sounds great with the exception of significant drone in 6th gear on the highway. One of the threads I've perused has pictures which suggest that the resonator on the stock 1M mid pipe is hollow (thus non-functional) and that this might explain the droning. What I'm thinking of doing is swapping my stock 1M mid pipe for a N54 mid pipe harvested from a 135i. My research suggests that the resonator is functional on the 135i mid pipe and that this might help with the problem. I've considered the N55 mid pipe but the comments regarding unpleasant odors and very loud start-up volume are steering me away from this swap. I would be interested in comments on my proposed plan or other suggestions regarding reducing/eliminating drone. I've upgraded the "flat storage compartment" (under the hard trunk liner in front of the battery compartment) with some Dynamat and Luxury Liner Pro and it has helped a bit but the drone persists. Thanks and I'm excited and happy to be a member of the 1M community! |
11-02-2020, 08:09 PM | #2 |
Ding Dong!
106
Rep 102
Posts |
I have the N55 midpipe, I don’t notice any extra smell.
Slightly louder upon cold start. The drone has moved to the 3k RPMs area and is a different tone. The exhaust note is improved. Power delivery is smoother. Small weight savings. Overall a great change except the DP to midpipe bolts all snapped off and I had to drill them all out. |
Appreciate
1
M_Thrizzle43.50 |
11-02-2020, 10:43 PM | #3 | |
Brigadier General
2314
Rep 4,341
Posts |
Quote:
Welcome and best of luck. |
|
Appreciate
0
|
11-02-2020, 11:36 PM | #4 |
Private
59
Rep 51
Posts |
From new, my stock 1M had a drone around 2,100 rpm at part throttle. It spanned a region of approximately 400 rpm and could become annoying on long gradual uphill sections of road. The n55 mid-pipe slightly reduced the volume of the drone and reduced its rpm band to approximately 200 rpm. With stock down pipes, the n55 mid-pipe did not create any unpleasant odors. Installing a Dinan axle back exhaust with the n55 pipe basically eliminated the drone. I now have the full Akrapovic Evolution exhaust, which has no drone. Furthermore, in quiet mode the Akra. exhaust is arguably quieter than stock.
Welcome to the 1M community... |
Appreciate
3
|
11-03-2020, 09:01 AM | #5 |
Colonel
2617
Rep 2,819
Posts
Drives: e82 1M, f87 M2cs
Join Date: Nov 2011
Location: Tri-Cities, Washington
|
My MadDad midpipe also reduced the drone's relative volume and narrowed the rpm band. Addition of Lightweight Ti rear section took it away almost completely, but I still hear it occasionally on long uphill sections.
__________________
1M track toy mods: BMS chargepipe, BMS OCC, ADE FMIC, ADE motor mounts, MadDad/Lightweight Ti exhaust, ADE custom oil thermostat/cooler, custom MHD tune, F10 550i clutch, Ohlins R+T, Vorschlag camber plates, M3 'vert FSB with Turner endlinks, Stoptech Trophy BBK.
|
Appreciate
0
|
11-03-2020, 05:42 PM | #6 |
Thread killer
643
Rep 1,896
Posts |
My experience was:
-the stock midpipe drones at highway speed -N55 midpipe drones a little bit less but you will notice it if you are sensitive to these things -- MechE's description above is spot-on -Maddad midpipe and Remus axleback does not drone, but it is noticeably louder than the stock setup |
Appreciate
1
M_Thrizzle43.50 |
11-03-2020, 06:21 PM | #7 |
New Member
8
Rep 25
Posts |
Thanks to all for the insight! All of the comments are helpful.
I'm still leaning towards harvesting a stock N54 mid pipe from a 135i if i can find one, assuming that it will have a functional resonator. I don't see any complaints about drone from owners with the 135i performance exhaust and my hope is that this could be a cost-effective solution. If I can't find one of these, I might purchase the N55 mid pipe after reviewing the information from the above posts. I could always consider grafting my 1M catalytic converters to the N55 mid pipe if I find the volume or smell objectionable but it sounds like I might be OK. I will definitely let the group know of the results. I'm still open to other suggestions and comments. Thanks again! This community is fantastic! |
Appreciate
0
|
11-03-2020, 08:09 PM | #8 | |
Thread killer
643
Rep 1,896
Posts |
Quote:
|
|
Appreciate
0
|
11-03-2020, 11:28 PM | #9 | |
Buck Sgt
144
Rep 355
Posts |
Quote:
|
|
Appreciate
0
|
11-04-2020, 04:58 PM | #10 | |
Ding Dong!
106
Rep 102
Posts |
Quote:
Once you remove the midpipe, the downpipe studs are easily accessible. |
|
Appreciate
1
ayao643.00 |
11-04-2020, 05:13 PM | #11 | |
New Member
8
Rep 25
Posts |
Quote:
My thinking is that the only difference between the mid pipe on the 135i (no drone) and the one on my 1M (which drones) is the fact that the 135I has a functional resonator. If the N55 mid pipe has a functional resonator then I'm essentially duplicating the mid pipe on the N54 135i by grafting the functional resonator of the N55 mid pipe to my 1M mid pipe catalytic converters. PLEASE correct me if I'm faulty on any of this reasoning as I really don't want to embark on a fruitless endeavor. Again, a sincere thanks to all for helping me with this! |
|
Appreciate
0
|
11-04-2020, 05:43 PM | #12 | |
Ding Dong!
106
Rep 102
Posts |
Quote:
I've considered getting a couple of inline resonators but that would involve me not being lazy. Not only that, the sound during acceleration and WOT is music to my ears |
|
Appreciate
0
|
11-30-2020, 09:38 PM | #13 |
Lieutenant
83
Rep 562
Posts
Drives: 2011 1M VO
Join Date: Dec 2011
Location: Chicago
|
I agree with moderate drone stock at 2100-2500, part throttle. Much better after catless DP; no smell cuz still have the midpipe. No codes with Cobb at least; passes inspection no prob in IL. Did I mention the extra HP and mild increase in volume (mostly at start-up, which I happen to like!)
|
Appreciate
0
|
12-19-2020, 06:39 PM | #14 |
New Member
8
Rep 25
Posts |
I did it! I purchased an OEM lightly used mid pipe off of a 135i with the N54 engine. I swapped my OEM 1M mid pipe for it. The 135i mid pipe has the secondary catalytic converters and what I'm assuming is a functional resonator. The drone is pretty much gone. Start-up is a bit less noisy, too. I really don't notice any difference in the character or volume of the exhaust note while actually driving the car and I don't notice any difference in the power band either.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|