04-30-2017, 11:21 PM | #1 |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Let's talk about drone and custom exhausts
So, I have been meaning to post this for a few days now...
I had received my new-to-me 2013 M5. Loved everything about it, except the sound. I am coming from 2003 M5 with Dinan Exhaust and love everything about it. So, I spoke to a friend who has done some exhaust work for other F10 m5s. He told me he would make a custom exhaust for me that would make the car sound A LOT better yet not obnoxious at all. So, he cleanly cut the OEM exhaust, and put in what seems to be some sort of resonator instead. Don't get me wrong, the car sounds AMAZING. Not obnoxious at all, and absolutely PERFECT. Everything I wanted. it sounds like a TRUE M Car and 4 inch exhaust tips just like I wanted. THE PROBLEM: Simple. The Car drones at 1500-1900 RPM. If I am cruising on the highway doing 70-80mph at 7th gear, I find myself going into 6th gear on purpose, just to keep the RPM right above 1900. Anything outside 1500-1900 RPM is dead Silent like stock. I dont know much about this, but the simple question is... Can I keep the sound as is and somehow LOSE this drone? The wife hates it, and I am growing sick of it. I've heard about sound deadning material between exhaust and chassis / rear trunk (DYNAMAT? ) I really don't want to go back to my OEM exhaust.... Thoughts? Here are a few pics of the OEM exhaust as it was cut, and the new setup. |
05-01-2017, 01:26 AM | #3 |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
|
Appreciate
0
|
05-01-2017, 10:24 AM | #4 | |
Captain
158
Rep 598
Posts |
Quote:
I disabled ASD and took out the stock resonators to replace it with 3-inch pipes. With the windows up my car sounds almost dead silent as stock too. This is the only thing frustrating with this car. My 4L twin turbo AMG had WAY more rumble and organic noise with no drone. What did BMW do to these cars? |
|
Appreciate
0
|
05-01-2017, 11:46 AM | #5 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
|
|
Appreciate
0
|
05-01-2017, 01:09 PM | #6 |
Captain
249
Rep 881
Posts |
Here's the simple solution that you may not want to hear...get rid of that setup. Been there, done that (Turner deletes). Yes, the drone is not bad if its not your daily driver and you dont drive family around. Yes, it sounds amazingly awesome outside of that RPM range, but cruising speeds will almost always end up in that drone zone....highways, parking lots, etc. It will gnaw away at your patience little by little, but worse, at your wife's patience lol.
__________________
2014 "AW/SO"me M5
Mission Performance/3.5 Bar RK Autowerks/ CSF ICs SSP Spec-R KW V3/ Corsa Axle back |
Appreciate
0
|
05-01-2017, 01:20 PM | #7 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
So,I guess modify oem exhaust to fit my tips and be done with it? Maybe keep valves open to keep a little bit of that Rumble? |
|
Appreciate
0
|
05-01-2017, 01:32 PM | #8 |
Major General
4226
Rep 5,276
Posts |
If you want some more rumble and no drone there are many axle-back / cat-back options that will provide a deeper exhaust note with zero drone (Akra, AWE, Eisenmann etc.). Not the best bang for your buck but you can certainly attain nice exhaust tone w/o drone. Some nice systems for sale on the classifieds.
__________________
CURRENT: 22' INDIVIDUAL M5| CHALK | TARTUFO | CCB | MPE | H&R | IND
GONE: 19' M5C| SINGAPORE GREY| ARAGON|VELOS VLS-06|H&R|iPE|IND|XPEL|CF|RADENSO GONE: 15' F10 M5|BSM|BLACK|VELOS VSS-S2|KW|AKRA|IND|CF |ESCORT 360|VELOS PIGGY GONE: 13' F10 M5|SG|BLACK|AKRA|KW|IND LONG GONE: 09' E60 M5|02' E39 M5 |
Appreciate
0
|
05-01-2017, 01:45 PM | #9 | |
Captain
158
Rep 598
Posts |
Quote:
I'll consider AWE or Magnaflow the next time I revisit the exhaust. For now, those valves are back to not being forced open and everything is fine. |
|
Appreciate
0
|
05-01-2017, 03:38 PM | #10 |
Captain
249
Rep 881
Posts |
I had settled on the AWE catback when a used set of Corsa/Turner mufflers listed in the classifieds....cant go wrong with those. I thought it too quiet at first, but it does open the ears in the high RPMs, and since going catless, its just right at lower RPMs, but with that crackling roar at high RPMs, characteristic of a catless setup.
__________________
2014 "AW/SO"me M5
Mission Performance/3.5 Bar RK Autowerks/ CSF ICs SSP Spec-R KW V3/ Corsa Axle back |
Appreciate
0
|
05-01-2017, 03:50 PM | #11 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
So I guess the valves are the ones that keep this under control? |
|
Appreciate
0
|
05-01-2017, 04:17 PM | #12 |
Captain
158
Rep 598
Posts |
I'm unsure about that. I don't have the stock resonators any more that's why it drones for me. Sounds like you still have them. You might be just fine.
|
Appreciate
0
|
05-01-2017, 04:21 PM | #13 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1098
Rep 1,967
Posts |
if you want to eliminate the drone, you need 1/4-wave resonators. I designed this on my previous car... full straight-thru system
|
Appreciate
2
6lacksheep92.50 Cylenterok136.00 |
05-01-2017, 06:05 PM | #14 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
1/4 wave resonators? Where to buy? How should they be welded on to current pipes... Does it matter where they are welded on? Excuse my ignorance, but im super interested |
|
Appreciate
0
|
05-01-2017, 06:12 PM | #15 | |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1098
Rep 1,967
Posts |
Quote:
They are just capped tubes... so you don't buy them. Need a fabricator to make them. I had calculated this for various RPM's and the resulting tube length. |
|
Appreciate
0
|
05-01-2017, 06:37 PM | #16 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
Shouldn't both tubes be the same length? |
|
Appreciate
0
|
05-01-2017, 06:43 PM | #17 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1098
Rep 1,967
Posts |
Only difference is the speed of sound value. Exhaust is hotter so speed of sound increases over temp. Use the higher value (top table). Same on both sides....
|
Appreciate
0
|
05-01-2017, 06:59 PM | #18 |
Captain
249
Rep 881
Posts |
Those look like helmholtz resonators employed by some aftermarket exhaust systems. I see them mostly in the JDM market...
__________________
2014 "AW/SO"me M5
Mission Performance/3.5 Bar RK Autowerks/ CSF ICs SSP Spec-R KW V3/ Corsa Axle back |
Appreciate
0
|
05-01-2017, 07:25 PM | #19 | |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
Quote:
what diameter should these pipes be? 3? 4 inches? |
|
Appreciate
0
|
05-01-2017, 07:47 PM | #22 |
First Lieutenant
133
Rep 355
Posts
Drives: E39 M5 | F10 M5 | F87 M2
Join Date: Mar 2017
Location: Santo Domingo, Dominican Republic
|
The video states to make sure the resonators are as close to the engine as possible so that it cancels the frequency as quickly as possible.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|