why some of the aftermarket exhaust have drone in low rpm

FVM3 · 09-24-2010, 08:37 AM

why some of the aftermarket exhaust have drone in low rpm? wt brand doesnt hv drone in low rpm...i do lot of driving in city so drone is disturbing me if it happens it low rpm

Daya · 09-24-2010, 09:00 AM

do you have AT or MT? seems to me it is mostly the AT drivers that experience drone at low RPM for whatever reason. I have bastuck, which is one of the more conservative exhausts with 6mt and have zero drone.

vasillalov · 09-24-2010, 09:10 AM

Because at low rpms you have a lot more vibrations and the engine is loaded quite a bit. Low rpms UNDER LOAD are not good for the engine to begin with...

Also, a vast majority of the aftermarket exhausts come either catless or with high flow cats and very high flow mufflers, items that normally muffle the sound. Just so you know, even the stock exhaust "drones" at low RPMS, you just can't hear it because it is very muffled.

FVM3 · 09-24-2010, 09:32 AM

i have automatic and had straight pipe and also custom made muffler before...drone in low rpm.....just wanna know if which brand doesnt have or have the least drone in low rpm

EastCoast335i · 09-24-2010, 01:38 PM

Quote:

Originally Posted by christopherchenm

i have automatic and had straight pipe and also custom made muffler before...drone in low rpm.....just wanna know if which brand doesnt have or have the least drone in low rpm

I know you're just looking for advice.. but i'd take what ppl say here with a grain of salt...

"drone" is subjective... what i consider drone you may not and vis versa...

best way to determine if an exhaust drones or not is to go to a local car meet, and go for a ride along with the exhausts you're considering...

cn555ic · 09-24-2010, 01:49 PM

Very true drone is subjective to different tolerances! I can say my exhaust drones minimal with Cpe exhaust with ar pipes and custom welded vibrant resonators

RocketFuel · 10-08-2010, 04:45 PM

Quote:

Originally Posted by cn555ic

Very true drone is subjective to different tolerances! I can say my exhaust drones minimal with Cpe exhaust with ar pipes and custom welded vibrant resonators

I have a CPE with their resonators and I can't stand the drone. My wife refuses to ride in my 335 because of the noise.

I am trying to find a way to reduce it. Not sure if harmonic dampeners will work or what.

enrita · 10-08-2010, 04:50 PM

you need resonators or a set of high flow cats to get rid of it especially with AT

shockin330i · 10-08-2010, 05:07 PM

my n55 has no cats in the pipes. I had cut the exhaust and it was a straight pipe all the way through.. The drone was so bad the coins in my cup holder would shake...

cn555ic · 10-08-2010, 06:08 PM

Quote:

Originally Posted by RocketFuel

I have a CPE with their resonators and I can't stand the drone. My wife refuses to ride in my 335 because of the noise.

I am trying to find a way to reduce it. Not sure if harmonic dampeners will work or what.

I am totally catless, but as for the resonators I didnt get it from CPE, I order a set of vibrant resonators and welded them on...Weird, I have no drone...I wonder if it can be the location of the resonators..I have mine welded on the midpipes...I wonder if the location also matters as where to weld the resonators! I guess the location of where I have the resonators made it perfectly tuned because yesterday I showed off my exhaust and my friends were amazed it was catless!

triggz · 10-08-2010, 06:31 PM

What do you guys consider drone?

scrufy · 10-08-2010, 06:51 PM

Quote:

Originally Posted by maxnix

Not necessarily for me. A drone is a mistune where a certain frequency hits a harmonic resonance and the voume (and usually vibration) is much higher in acoustic energy. I think few 3rd party after market vendors have the resources to research each exhaust (or intake, for that matter) that it offers for sale. Even some OEM (Porsche Cayman S comes to mind) have some poor resonance tuning.

First answer that was right.... Yup, you could auctaully tune the drone out by adding a length of pipe to the side parallel to the pipe but tuning it to the right length is too much trouble and sometimes too long of a pipe.
FWIW I have the PE and it has no drone. If you get on it more than 1/4 throttle tjough...look out. It gets loud quick.

Belarus · 10-09-2010, 02:23 AM

Quote:

Originally Posted by enrita

you need resonators or a set of high flow cats to get rid of it especially with AT

From my personal experience cat-less AR DPs with aftermarket exhaust system that had HFC (BTW vendor promotes it as drone free exhaust on this forum...

) did minimum to reduce drone on AT. For a DD car it wasn't tolerable to me.

Switched back to stock exhaust, did 'golf tee" mod and I couldn't been happier with the sound, luv it every time I drive my car with roof down and get to hear it. BTW there is still a very minimum drone that I personally barely notice and find non intrusive.

howiedds · 10-09-2010, 12:02 PM

even golf tee mod drones...so its unavoidable...lol

tofu- · 10-09-2010, 12:18 PM

would having more than one resonator per pipe make a difference? i am under the impression that the e92 already has a couple of resonators. i was thinking of adding another couple to really get rid of that low rpm "drone" (although it isn't bad at all) with my bastuck and catless dps. if they're still effective, i could really fine tune my exhaust note

Jeff@TopGearSolutions · 10-09-2010, 12:29 PM

I admit I hate drone...

Drone is a resonance in the cabin more or less by vibration (or harmonic vibrations).

The exhaust can be pretty quiet in sound but can drone at certain rpms and you can almost feel it in the cabin.

I'm curious as to what cat backs dont have this effect, we all know they provide minimal gains.

It's funny barely any exhaust ever mentions the design of the muffler and resonator which are a true sign of how it will perform.

2.5 inch piping is one thing, but if the muffler is baffled, louvered, or perforated core straight through, its going to make the difference in the actual performance.

markkbp · 10-10-2010, 09:34 AM

Hey guys, i just install UR exhaust and the drone at low rpm is driving me crazy!!! Also it's pretty loud

. What can i do???

Belarus · 10-10-2010, 07:42 PM

Quote:

Originally Posted by markkbp

Hey guys, i just install UR exhaust and the drone at low rpm is driving me crazy!!! Also it's pretty loud

. What can i do???

Go back to stock or try cn555ic's solution. BTW curious do you have stock DP's or aftermarket ?

ttomczak · 10-11-2010, 12:07 AM

Between my Vettes, my "former" M6 and now my 335i E93, I am extremely susceptible to drone...

I am running a cat back Corsa / UUC exhaust... There is NO drone at any speed, great sound when getting on it, nice burble during decel...

Quiet on gentle cruising...

Hope this helps...

atlxkevinx · 11-12-2010, 05:10 PM

Quote:

Originally Posted by ttomczak

Between my Vettes, my "former" M6 and now my 335i E93, I am extremely susceptible to drone...

I am running a cat back Corsa / UUC exhaust... There is NO drone at any speed, great sound when getting on it, nice burble during decel...

Quiet on gentle cruising...

Hope this helps...

I just installed the UUC axle-back exhaust and it drones like crazy in the low rpms! maybe because I have all 4 cats? I have a 6MT btw.

Do you think I should replace the 2 cats in the midpipe with resonators to cure the droning issue?

i2iSTUDIOS · 11-12-2010, 05:46 PM

I hear BMW Performance exhaust doesn't drone.

enrita · 11-12-2010, 05:52 PM

the drone is amplified a lot by the way the main mufflers from the axle back are built. My Bastuck for example with AR catless dps and OEM midsection with cats did not drone a bit.
When i removed the middle cats the drone and rasp between 1500-2000 rpm was unbearable.
After putting resonators 3/4 of it disappeared but there is still some rasp.
I am gonna put HighFlow cats now to fix the smell and hopefully the rasp/drone as well.

09-24-2010, 08:37 AM	#1
FVM3 Major General 273 Rep 5,751 Posts Drives: e92 m3, f30 328i Join Date: Sep 2010 Location: Los Angeles iTrader: (2)	why some of the aftermarket exhaust have drone in low rpm why some of the aftermarket exhaust have drone in low rpm? wt brand doesnt hv drone in low rpm...i do lot of driving in city so drone is disturbing me if it happens it low rpm
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09-24-2010, 09:00 AM	#2
Daya Lieutenant Colonel 200 Rep 1,741 Posts Drives: e92 335 space gray/coral red Join Date: Sep 2006 Location: Chicago iTrader: (1) Garage List 2007 E92 335 [9.66]	do you have AT or MT? seems to me it is mostly the AT drivers that experience drone at low RPM for whatever reason. I have bastuck, which is one of the more conservative exhausts with 6mt and have zero drone. __________________ GIAC S2 \| Brembo GT BBK 355/345 \| BBS CH-R \| Michelin Pilot Super Sports \| AR Design: DP, S1 Oil Cooler, OCC \| AMS FMIC \| Bastuck Quad Exhaust \| Borla MP \| KW V1 \| Stett: CAI, CP \| Forge DV \| P3 Boost Gauge \| Arkym: Front Lip, Rear Quad Diffuser \| Vorsteiner CSL Trunk \| LUX H8 \| ModMyNav \| MFD M3 Sideskirts \| BMW M-Tech Front/Rear Bumpers, Edition Grills
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09-24-2010, 09:10 AM	#3
vasillalov Mad Linux Guru On The Loose 1121 Rep 5,396 Posts Drives: 2008 335i Sedan, 2023 M3 Join Date: Aug 2009 Location: Chicago, IL iTrader: (5) Garage List 2023 BMW M3 [0.00] 2008 335i E90 [8.00]	Because at low rpms you have a lot more vibrations and the engine is loaded quite a bit. Low rpms UNDER LOAD are not good for the engine to begin with... Also, a vast majority of the aftermarket exhausts come either catless or with high flow cats and very high flow mufflers, items that normally muffle the sound. Just so you know, even the stock exhaust "drones" at low RPMS, you just can't hear it because it is very muffled. __________________ 6MT \| COBB \| AR \| AE \| Forge DV \| HPF \| P3 Gauge \| Hybrid Intake \| O.S.Giken TCD \| All M3 bits \| TCKLine \| StopTech \| UUC \| ER \| SPEC
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09-24-2010, 09:32 AM	#4
FVM3 Major General 273 Rep 5,751 Posts Drives: e92 m3, f30 328i Join Date: Sep 2010 Location: Los Angeles iTrader: (2)	i have automatic and had straight pipe and also custom made muffler before...drone in low rpm.....just wanna know if which brand doesnt have or have the least drone in low rpm
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09-24-2010, 01:49 PM	#6
cn555ic 441 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	Very true drone is subjective to different tolerances! I can say my exhaust drones minimal with Cpe exhaust with ar pipes and custom welded vibrant resonators
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10-08-2010, 04:50 PM	#8
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	you need resonators or a set of high flow cats to get rid of it especially with AT __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
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10-08-2010, 05:07 PM	#9
shockin330i Brigadier General 798 Rep 4,784 Posts Drives: 2016 ZCP M3 Join Date: Jan 2007 Location: f y'all, I'm from Texas (RGV) iTrader: (1)	my n55 has no cats in the pipes. I had cut the exhaust and it was a straight pipe all the way through.. The drone was so bad the coins in my cup holder would shake... __________________ ERnie 2016 BSM/f80/ZCP
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10-08-2010, 06:31 PM	#11
triggz Banned 56 Rep 1,224 Posts Drives: E92 335i Join Date: Jun 2010 Location: Toronto iTrader: (2)	What do you guys consider drone?
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10-09-2010, 12:02 PM	#14
howiedds D.D.S. 31 Rep 460 Posts Drives: 12 AW E70 X5d Join Date: Sep 2009 Location: Brooklyn, NY iTrader: (5)	even golf tee mod drones...so its unavoidable...lol
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10-09-2010, 12:18 PM	#15
tofu- Banned 87 Rep 2,854 Posts Drives: 335i Jet Black/Coral Red Join Date: Mar 2010 Location: nyc iTrader: (4)	would having more than one resonator per pipe make a difference? i am under the impression that the e92 already has a couple of resonators. i was thinking of adding another couple to really get rid of that low rpm "drone" (although it isn't bad at all) with my bastuck and catless dps. if they're still effective, i could really fine tune my exhaust note
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10-09-2010, 12:29 PM	#16
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	I admit I hate drone... Drone is a resonance in the cabin more or less by vibration (or harmonic vibrations). The exhaust can be pretty quiet in sound but can drone at certain rpms and you can almost feel it in the cabin. I'm curious as to what cat backs dont have this effect, we all know they provide minimal gains. It's funny barely any exhaust ever mentions the design of the muffler and resonator which are a true sign of how it will perform. 2.5 inch piping is one thing, but if the muffler is baffled, louvered, or perforated core straight through, its going to make the difference in the actual performance.
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10-10-2010, 09:34 AM	#17
markkbp Private 5 Rep 71 Posts Drives: 335 Join Date: Sep 2010 Location: ca iTrader: (2)	Hey guys, i just install UR exhaust and the drone at low rpm is driving me crazy!!! Also it's pretty loud. What can i do???
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10-11-2010, 12:07 AM	#19
ttomczak Private First Class 18 Rep 182 Posts Drives: 2015 X5 3.5 M-Sport Join Date: Aug 2010 Location: North Carolina iTrader: (5)	Between my Vettes, my "former" M6 and now my 335i E93, I am extremely susceptible to drone... I am running a cat back Corsa / UUC exhaust... There is NO drone at any speed, great sound when getting on it, nice burble during decel... Quiet on gentle cruising... Hope this helps... __________________ 2015 F15 X5 3.5i M-Sport SG Past Rides: 2001 E39 Dinan 5 - 2006 E63 M6 - 2007 335i E93 - 2007 X5 E70 4.8i - 2010 X5 E70 3.0i 2016 428ix M-Sport Gran Coupe - 2014 E71 X6M
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11-12-2010, 05:46 PM	#21
i2iSTUDIOS Captain 88 Rep 870 Posts Drives: BMW 335i Coupe Join Date: Mar 2008 Location: Cincinnati, OH iTrader: (1)	I hear BMW Performance exhaust doesn't drone. __________________ 2007 E92 335i / 6MT / Monaco Blue Metallic / Gray Dakota Leather / Comfort Assist / Premium / Sport / Heated Seats / Navi / Active Steering / Active Cruise Control / Park Distance Control / Rear Sunshade / Sirius MODS PicoTray / M3 Steering Wheel / Front OEM Aero Lip / Bimmian Aluminum Pedals / CDV / Ram Air Scoops / Painted Reflectors / HID 5000k / LED Angels / M Perf. Shifter / Euro Light Switch / 8500 x50 / Center Armrest Pouch / JB4 / BT
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11-12-2010, 05:52 PM	#22
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	the drone is amplified a lot by the way the main mufflers from the axle back are built. My Bastuck for example with AR catless dps and OEM midsection with cats did not drone a bit. When i removed the middle cats the drone and rasp between 1500-2000 rpm was unbearable. After putting resonators 3/4 of it disappeared but there is still some rasp. I am gonna put HighFlow cats now to fix the smell and hopefully the rasp/drone as well. __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
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