Previous Thread
Next Thread
Print Thread
Page 2 of 4 1 2 3 4
Re: Exhaust drone, how to get it to go away!!!! [Re: 340727dart] #67721
06/05/08 03:20 PM
06/05/08 03:20 PM
Joined: Aug 2005
Posts: 4,861
Riverside, Ca
R70RUNNER Offline
master
R70RUNNER  Offline
master

Joined: Aug 2005
Posts: 4,861
Riverside, Ca
I put dyna-mat under the rear seat, and up the axle well behind the rear back rest, jute behind the devider board. much quiter inside the car now. There's still a very faint drone at 45, not obnoxious but I can tell it would be 100x worse with out the deadner

Manifolds
TTI 2.5"
X-pipe
Dynomax muffs


Current cars: 2000 Dak Quad Cab, 2012 Challenger,1970 Road Runner, 1994 Firehawk


1966 Coronet post sedan, 1988 Corvette, 2005 Magnum RT all SOLD

R70RUNNER<---VP Inland Empire Chapter of the MPM
Re: Exhaust drone, how to get it to go away!!!! [Re: R70RUNNER] #67722
06/05/08 03:39 PM
06/05/08 03:39 PM
Joined: Jan 2003
Posts: 3,329
Melbourne, FL
dwbiggs Offline
super gas
dwbiggs  Offline
super gas

Joined: Jan 2003
Posts: 3,329
Melbourne, FL
I have 1 7/8" TTIs and Dynomax Super turbos w/ 2.5"pipe. I was surprised to find that I had no drone. I to used dynamat but I have no idea whether that made the difference. Oh...and I do have an h-pipe.

Last edited by dwbiggs; 06/05/08 03:40 PM.
Re: Exhaust drone, how to get it to go away!!!! [Re: dwbiggs] #67723
06/05/08 04:33 PM
06/05/08 04:33 PM
Joined: May 2003
Posts: 1,603
germany
440sat72 Offline
top fuel
440sat72  Offline
top fuel

Joined: May 2003
Posts: 1,603
germany
i have headers plus a 3" TTi X.Pipe System with the long Dynomax Super Turbos. Cars is packed with Raamat and Ensolite foam. Everything is fine as long as i have at leas one side of windows shut. As sonn as i open all the windows i have a very bad drone – but only at idle speed (makes me hate stoplights)

Re: Exhaust drone, how to get it to go away!!!! [Re: Weldtech] #67724
06/05/08 10:42 PM
06/05/08 10:42 PM
Joined: Aug 2006
Posts: 247
DuPont, Washington
D
DZJim Offline
enthusiast
DZJim  Offline
enthusiast
D

Joined: Aug 2006
Posts: 247
DuPont, Washington
Well, I'm not an acoustics engineer or any other kind of engineer, but it sounds like you have a passive radiator problem. In other words the panel or componenet that is vibrating is not being excited directly, but is just transmitting the vibrations.
Used to be a stereo speaker back in the 60s or 70s that use this idea to "enhance" bass frequencies.

What you have to do is add mass (undercoating, stick-on insulator, etc to the panel or item, or support it more ridgidly. Something to get the culprit's resonant frequency away from the exhaust system frequecny

The panel or componenet might be behind the headliner or unedr the carpets or in the trunk. Problem is to find it.

Or do what I did after my second set of glass-packs: ditch the duals and glasspacks and install stock single exhaust. Ahhhh peace and quiet....

I'd go for undercoating for sure.

My $0.02

Re: Exhaust drone, how to get it to go away!!!! [Re: Weldtech] #67725
06/06/08 02:46 PM
06/06/08 02:46 PM
Joined: Jan 2003
Posts: 2,805
541 slobovia
A990 Offline
master
A990  Offline
master

Joined: Jan 2003
Posts: 2,805
541 slobovia
Our Dakota had a horrible drone that vanished when the headers were increased from 5/8 to 3/4 primaries.

Maybe you can use larger diameter pipe between the manifolds and muffler? Drone is the most uncomfortable thing to endure, so good luck!

Re: Exhaust drone, how to get it to go away!!!! [Re: A990] #67726
06/06/08 03:23 PM
06/06/08 03:23 PM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



Are you using the factory muffler shield?? It should stop a lot of the noise before it hits the floor.

Oh yea, NEVER buy a Lil Red Express,cause there is some drone....

Re: Exhaust drone, how to get it to go away!!!! [Re: 440sat72] #67727
06/06/08 03:45 PM
06/06/08 03:45 PM
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
torkrules Offline
I'm neurotic
torkrules  Offline
I'm neurotic

Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
Quote:

i have headers plus a 3" TTi X.Pipe System with the long Dynomax Super Turbos. Cars is packed with Raamat and Ensolite foam. Everything is fine as long as i have at leas one side of windows shut. As sonn as i open all the windows i have a very bad drone – but only at idle speed (makes me hate stoplights)




Mine drones at 3000rpm. Almost want to jump out the window (while the cars moving). Right now I solve the problem by slowing down to 55MPH (2500 rpm). Over the winter I'll change the mufflers out to Ultra Flows. Had them on the Charger without tail pipes and there was absolutely no drone.

Re: Exhaust drone, how to get it to go away!!!! [Re: torkrules] #67728
06/06/08 05:31 PM
06/06/08 05:31 PM
Joined: Jun 2003
Posts: 746
Missouri
NFURY8 Offline
super street
NFURY8  Offline
super street

Joined: Jun 2003
Posts: 746
Missouri
I have a super turbo on my V6 Dakota and it has an annoying drone over 50 mph.

My Fury has a healthy 440, TTI headers, 3" exhaust, no cross over and Cherry Bomb Vortex mufflers. I am told it is really loud when followed, it can be heard over a mile away! However it is very comfortable when driving, you can easily hold a conversation at 70 mph with the top up or down. The Vortex mufflers have a very low restriction, slightly curved follow path, but the case is super thick and solid. They have a deep, rich, mellow sound, but they heavy case seems to help funnel all the noise out the back, rather than up through the body. The only insulation in my car is the jute carpet padding.

I have experienced the same results when I used to have iron manifolds and 40" long glass packs. My brother used to have 24" packs on a Duster that was awful, I have had 36" and 40" packs on a couple vehicles with great sound and no drone or cackle.

I think the thicker cases help the drone a lot. i wouldn't use the Vortex on something I raced though, they are heavy, not will never rust out!


C-Body DryDock Bigger is Better!
Re: Exhaust drone, how to get it to go away!!!! [Re: NFURY8] #67729
06/06/08 05:48 PM
06/06/08 05:48 PM
Joined: Jan 2006
Posts: 3,535
Canuckville
68Cbarge Offline
master
68Cbarge  Offline
master

Joined: Jan 2006
Posts: 3,535
Canuckville
If you want a quiet exhaust--buy a Rolls Royce!
Someone is onto something in regards to the undercoating.Not only does it "protect" is also deadens any noise from the ehxaust.
But not everybody likes the look of its black ugliness-especially after all the hard work detailing the belly of the beast.
May I suggest installing dynamat or something similar under the carpet to quiet the cabin.
Nobody sees it,and you can still show the underside nice and purdy.Then run whatever exhaust you prefer.
Much easier and affordable than spending big bux and wasting time on swapping exhaust systems that will still be loud.


'68 Newport Custom Barge on a Budget!! BOAB
1973 Satellite WAGON! 318- 3 on the tree!!
2008 Chrysler 300c HEMI!
Re: Exhaust drone, how to get it to go away!!!! [Re: 68Cbarge] #67730
06/06/08 06:24 PM
06/06/08 06:24 PM
Joined: Apr 2007
Posts: 1,261
ILL
mark7171 Offline
pro stock
mark7171  Offline
pro stock

Joined: Apr 2007
Posts: 1,261
ILL
if your looking for a sound that you can legally get away with on a hot big block....4(2x2) mufflers reducing to 2x 2 1/2" or less outlets.

only way to get these machines quiet.

the resonator you tried meant glasspack, right? or was it just a tip? anyways install the glasspack before the muffler to get that benefit.

no 3" outlets. it opens up a new group of low harmonics that penetrate. its affecting people not even able to look at your car...thats kind of stupid.

didnt some magazine do a backpressure study and found that rear tailpipes account for some "measureable" forward thrust?

Last edited by mark7171; 06/06/08 06:34 PM.
Re: Exhaust drone, how to get it to go away!!!! [Re: mark7171] #67731
06/06/08 07:20 PM
06/06/08 07:20 PM
Joined: Feb 2004
Posts: 7,197
Harrisburg, Pa.
screamindriver Offline
master
screamindriver  Offline
master

Joined: Feb 2004
Posts: 7,197
Harrisburg, Pa.
Insulate, insulate, then insulate some more... That's the best advice...I've got A/C so I added some thick jute carpet padding on the floor,roof, jute padding under the back seat and wheel well areas,on the package tray and rear divider as well as foil type behind the door panels...And I inadvertently quieted the whole seating area down dramatically... I've got Hooker 1 7/8 super comp headers and a complete TTI 3 inch "H" pipe{which is louder than the X}with the super turbos and there's no drone or resonance...You have to roll the windows down if you want to hear it loud...And it definitely sounds different to the people outside or behind the car on the road...

Re: Exhaust drone, how to get it to go away!!!! [Re: screamindriver] #67732
06/06/08 09:31 PM
06/06/08 09:31 PM
Joined: Jan 2008
Posts: 328
Missouri, U.S.A.
J
JSSuperbee Offline
enthusiast
JSSuperbee  Offline
enthusiast
J

Joined: Jan 2008
Posts: 328
Missouri, U.S.A.
Won't all that insulation prohibit the shaped and properly contoured carpet from fitting properly?


James Stinebaker
Re: Exhaust drone, how to get it to go away!!!! [Re: JSSuperbee] #67733
06/07/08 06:36 AM
06/07/08 06:36 AM
Joined: Mar 2005
Posts: 2,060
Pendleton NY
T
terzmo Offline
top fuel
terzmo  Offline
top fuel
T

Joined: Mar 2005
Posts: 2,060
Pendleton NY
I've got hooker 2 inch headers and 3 inch exhaust to the axel and 2 and 1/2 out the rear bumper on My 67 GTX.H pipe.(flowmasters 40,sounds great) 440 stroked and bored to 498. I have that damn drone at 45 to 70 mph ...not real bad..but there...if You figure it out..let Me know. I have zero floor insulation and will give that a shot. Thanks to all for their input

Re: Exhaust drone, how to get it to go away!!!! [Re: Weldtech] #67734
06/08/08 12:24 AM
06/08/08 12:24 AM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



I fought your same problem with my 70 Challenger with the TTI 2.5 and manifolds, both with just the Dynomax and with resonators behind the dynomax.

my car has undercoating and I had lined the interior with sound deadening/heat blocker and from 2K to 2.5K I had a drone so bad my ears would ache all day after just a 20 min ride.


I finally changed everything to a stock style exhaust from Accurrate LTD and now it is a pleasure to drive.

Re: Exhaust drone, how to get it to go away!!!! [Re: Weldtech] #67735
06/08/08 12:33 AM
06/08/08 12:33 AM
Joined: Oct 2004
Posts: 16,489
Canada
CrAzYMoPaRGuY Offline
I Live Here
CrAzYMoPaRGuY  Offline
I Live Here

Joined: Oct 2004
Posts: 16,489
Canada
Try this and tell how oh how you never did it before......

ADD RESONATORS!!!!!!!!!!!

Toss some GOOD resonators at the back, get rid of the drone. Add two more mufflers, get rid of the drone. Add Dynamat and try to mask the drone....


CrAzYMoPaRGuY
Re: Exhaust drone, how to get it to go away!!!! [Re: JSSuperbee] #67736
06/08/08 07:08 AM
06/08/08 07:08 AM
Joined: Feb 2004
Posts: 7,197
Harrisburg, Pa.
screamindriver Offline
master
screamindriver  Offline
master

Joined: Feb 2004
Posts: 7,197
Harrisburg, Pa.
Quote:

Won't all that insulation prohibit the shaped and properly contoured carpet from fitting properly?


No,in this case I did'nt use the original{and heavy} tar type floor insulation and used the newer style jute matting over the floors and hump...It really cut down on the heat and noise in the seating compartment.....And to be honest all the die formed carpeting I've used no matter which model, just does'nt fit as accurately as the manufacturer would lead you to beleive so it had little affect on the end fitting...On that note,I saw a perfectly fitting carpet at a national show one year and just had to ask how it fit so well...Turns out he completely glued the carpet in place !!! .....

Re: Exhaust drone, how to get it to go away!!!! [Re: CrAzYMoPaRGuY] #67737
06/08/08 09:50 AM
06/08/08 09:50 AM
Joined: Jan 2005
Posts: 279
Pacific Northwest
W
Weldtech Offline OP
enthusiast
Weldtech  Offline OP
enthusiast
W

Joined: Jan 2005
Posts: 279
Pacific Northwest
Quote:



ADD RESONATORS!!!!!!!!!!!




I did that with no change whatsoever......


www.weldtechstainless.com Where NOTHING is made in China! 70 Challenger drop top 440 4 speed R/T clone (Re-creation, Tribute, Fake, whatever...)
Re: Exhaust drone, how to get it to go away!!!! #67738
06/08/08 10:08 AM
06/08/08 10:08 AM
Joined: Jan 2005
Posts: 279
Pacific Northwest
W
Weldtech Offline OP
enthusiast
Weldtech  Offline OP
enthusiast
W

Joined: Jan 2005
Posts: 279
Pacific Northwest
Quote:

I fought your same problem with my 70 Challenger with the TTI 2.5 and manifolds, both with just the Dynomax and with resonators behind the dynomax.

my car has undercoating and I had lined the interior with sound deadening/heat blocker and from 2K to 2.5K I had a drone so bad my ears would ache all day after just a 20 min ride.


I finally changed everything to a stock style exhaust from Accurrate LTD and now it is a pleasure to drive.




If I can't get it to go away that would be my next option...

Lots of good suggestions on here but I have pretty much done it all except change to a different style of muffler. I have undercoating on the underside of the whole car AND the topside of the floor with insulation under the carpet, I went from cheap turbos with a single layer case to Dynomax with 2 layers, I eliminated the crossover, I added resonators, all with no change except a slight reduction with eliminating the crossover. Tis hard for me to add anything under the headliner as I don't have one....

I was unable to find any quiet mufflers that would fit, however I did talk to someone at a speed shop about different mufflers, he suggested I try Magnaflow instead of Flowmaster.

I picked up a pair of those and will let you know how that goes.

If anything is going to work I think it will be them as the case is packed with insulation which should deaden any harmonics..... I hope.....

Or I might have to put an amp on my AM 8 Track!


www.weldtechstainless.com Where NOTHING is made in China! 70 Challenger drop top 440 4 speed R/T clone (Re-creation, Tribute, Fake, whatever...)
Re: Exhaust drone, how to get it to go away!!!! [Re: Weldtech] #67739
06/08/08 01:01 PM
06/08/08 01:01 PM
Joined: Oct 2004
Posts: 16,489
Canada
CrAzYMoPaRGuY Offline
I Live Here
CrAzYMoPaRGuY  Offline
I Live Here

Joined: Oct 2004
Posts: 16,489
Canada
Quote:

Quote:



ADD RESONATORS!!!!!!!!!!!




I did that with no change whatsoever......




What kind of resonators did you use? To add resonators and have NO change whatsoever leaves me wondering what you used!


CrAzYMoPaRGuY
Re: Exhaust drone, how to get it to go away!!!! [Re: CrAzYMoPaRGuY] #67740
06/08/08 02:21 PM
06/08/08 02:21 PM
Joined: Mar 2003
Posts: 4,848
Memphis
HemiRick Offline
master
HemiRick  Offline
master

Joined: Mar 2003
Posts: 4,848
Memphis
My 70 Challenger 451 has a complete TTI 2.5 system and headers and it only drones at idle. Interior is completely original stock.


Take care,
Rick
68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451
Page 2 of 4 1 2 3 4






Powered by UBB.threads™ PHP Forum Software 7.7.1