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Update. Exhaust drone, how to get it to go away!!!!
#67701
06/04/08 08:45 PM
06/04/08 08:45 PM
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Joined: Jan 2005
Posts: 279
Pacific Northwest
Weldtech
OP
enthusiast
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OP
enthusiast
Joined: Jan 2005
Posts: 279
Pacific Northwest
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I finally installed the Magnaflows, if anything was going to cure the drone I thought they would do it as they are packed tight with insulation and the exhaust does not actually bounce around inside the empty body of the mufflers.... While it is definitely better the drone is still there, not nearly as bad but.... I give up.... almost! If I can't get used to it I guess a stock type system is next, either that or try Flowmasters, but how many mufflers do I try...  I hope somebody out there can help.... 70 Challenger drop top, healthy 440, 3.55 gears. 1st - Headers and 3" exhaust with Dynomax Super Turbos and X pipe, very loud, pulsing drone/noise and did not like the sound of the X, had trouble with the ceramic coating on the headers twice and decided to ditch the whole system. 2nd - Manifolds and 2 1/2" pipe with crossover, cheap Thrush Turbos, very bad drone. 3rd - changed mufflers to Dynomax Super turbos, no change. 4th - Added 4" dia resonators before the tips, outside sound changed but no reduction in the drone. 5th - Plugged the crossover, slight reduction, the car is still quite loud (vibrates and shakes overhead covers in gas stations) but not bad when driving except at 40 to 45 MPH of course, AHHHHHHH. Anybody have this type of thing happen to them? Any ideas or suggestions? I am thinking of changing to a quiet type of muffler, any good quieter performance mufflers available? Cheerio, Rob
Last edited by Weldtech; 06/28/08 06:50 PM.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67702
06/04/08 08:52 PM
06/04/08 08:52 PM
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Joined: Jun 2006
Posts: 824
NH
72challorange
He's Game
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He's Game
Joined: Jun 2006
Posts: 824
NH
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Re: Exhaust drone, how to get it to go away!!!!
[Re: 72challorange]
#67704
06/04/08 08:57 PM
06/04/08 08:57 PM
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Joined: Jan 2005
Posts: 279
Pacific Northwest
Weldtech
OP
enthusiast
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OP
enthusiast
Joined: Jan 2005
Posts: 279
Pacific Northwest
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Yeah......
What gets me is that I have sold the identical systems to others and they have no drone!!!
Why my car?????
www.weldtechstainless.com
Where NOTHING is made in China!
70 Challenger drop top 440 4 speed R/T clone (Re-creation, Tribute, Fake, whatever...)
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67706
06/04/08 08:59 PM
06/04/08 08:59 PM
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Joined: Jun 2006
Posts: 824
NH
72challorange
He's Game
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He's Game
Joined: Jun 2006
Posts: 824
NH
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Just messin with ya! Maybe a different muffler will do you. I have 40 series and enjoy the drone.LOL Tom 
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67710
06/04/08 09:15 PM
06/04/08 09:15 PM
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Joined: Jun 2006
Posts: 824
NH
72challorange
He's Game
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He's Game
Joined: Jun 2006
Posts: 824
NH
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I use this to drown out the drone.LOL Tom  By tdavist, shot with DSC-P72 at 2008-04-06
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67713
06/04/08 09:29 PM
06/04/08 09:29 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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just a thought
how is your ca finished
just paint on bottom of car or undercoating
how about floor padding to custion the sound resinating through the body
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67714
06/04/08 09:37 PM
06/04/08 09:37 PM
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Joined: Jan 2003
Posts: 8,144
Arkansas
340727dart
master
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master
Joined: Jan 2003
Posts: 8,144
Arkansas
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My DynoMax super turbos had a slight drone around 40 mph. I put some Ultra Flows on the car and they have no drone. Plus, they sound so much better than the turbos.
Your life is not my fault.
My life is none of your business.
Speech is free only if you agree with those in control.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: 340727dart]
#67721
06/05/08 04:20 PM
06/05/08 04:20 PM
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Joined: Aug 2005
Posts: 4,861
Riverside, Ca
R70RUNNER
master
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master
Joined: Aug 2005
Posts: 4,861
Riverside, Ca
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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
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Re: Exhaust drone, how to get it to go away!!!!
[Re: R70RUNNER]
#67722
06/05/08 04:39 PM
06/05/08 04:39 PM
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Joined: Jan 2003
Posts: 3,329
Melbourne, FL
dwbiggs
super gas
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super gas
Joined: Jan 2003
Posts: 3,329
Melbourne, FL
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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 04:40 PM.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: A990]
#67726
06/06/08 04:23 PM
06/06/08 04:23 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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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....
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Re: Exhaust drone, how to get it to go away!!!!
[Re: 440sat72]
#67727
06/06/08 04:45 PM
06/06/08 04:45 PM
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Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
torkrules
I'm neurotic
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I'm neurotic
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
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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.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: torkrules]
#67728
06/06/08 06:31 PM
06/06/08 06:31 PM
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Joined: Jun 2003
Posts: 746
Missouri
NFURY8
super street
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super street
Joined: Jun 2003
Posts: 746
Missouri
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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!
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Re: Exhaust drone, how to get it to go away!!!!
[Re: NFURY8]
#67729
06/06/08 06:48 PM
06/06/08 06:48 PM
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Joined: Jan 2006
Posts: 3,535
Canuckville
68Cbarge
master
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master
Joined: Jan 2006
Posts: 3,535
Canuckville
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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!
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Re: Exhaust drone, how to get it to go away!!!!
[Re: 68Cbarge]
#67730
06/06/08 07:24 PM
06/06/08 07:24 PM
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Joined: Apr 2007
Posts: 1,261
ILL
mark7171
pro stock
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pro stock
Joined: Apr 2007
Posts: 1,261
ILL
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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 07:34 PM.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: mark7171]
#67731
06/06/08 08:20 PM
06/06/08 08:20 PM
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Joined: Feb 2004
Posts: 7,195
Harrisburg, Pa.
screamindriver
master
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master
Joined: Feb 2004
Posts: 7,195
Harrisburg, Pa.
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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... 
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Re: Exhaust drone, how to get it to go away!!!!
[Re: screamindriver]
#67732
06/06/08 10:31 PM
06/06/08 10:31 PM
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Joined: Jan 2008
Posts: 328
Missouri, U.S.A.
JSSuperbee
enthusiast
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enthusiast
Joined: Jan 2008
Posts: 328
Missouri, U.S.A.
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Won't all that insulation prohibit the shaped and properly contoured carpet from fitting properly?
James Stinebaker
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67734
06/08/08 01:24 AM
06/08/08 01:24 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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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.
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67735
06/08/08 01:33 AM
06/08/08 01:33 AM
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Joined: Oct 2004
Posts: 16,477
Canada
CrAzYMoPaRGuY
I Live Here
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I Live Here
Joined: Oct 2004
Posts: 16,477
Canada
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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
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Re: Exhaust drone, how to get it to go away!!!!
[Re: JSSuperbee]
#67736
06/08/08 08:08 AM
06/08/08 08:08 AM
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Joined: Feb 2004
Posts: 7,195
Harrisburg, Pa.
screamindriver
master
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master
Joined: Feb 2004
Posts: 7,195
Harrisburg, Pa.
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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 !!!  .....
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Re: Exhaust drone, how to get it to go away!!!!
#67738
06/08/08 11:08 AM
06/08/08 11:08 AM
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Joined: Jan 2005
Posts: 279
Pacific Northwest
Weldtech
OP
enthusiast
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OP
enthusiast
Joined: Jan 2005
Posts: 279
Pacific Northwest
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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...)
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Re: Exhaust drone, how to get it to go away!!!!
[Re: CrAzYMoPaRGuY]
#67740
06/08/08 03:21 PM
06/08/08 03:21 PM
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Joined: Mar 2003
Posts: 4,848
Memphis
HemiRick
master
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master
Joined: Mar 2003
Posts: 4,848
Memphis
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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
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Re: Exhaust drone, how to get it to go away!!!!
[Re: CrAzYMoPaRGuY]
#67742
06/10/08 03:29 AM
06/10/08 03:29 AM
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Joined: Aug 2007
Posts: 173
East TN.
Moparsky
member
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member
Joined: Aug 2007
Posts: 173
East TN.
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Quote:
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!
What brand & model number resonators would you guys recommend ?
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Re: Exhaust drone, how to get it to go away!!!!
[Re: Weldtech]
#67743
06/10/08 11:35 AM
06/10/08 11:35 AM
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Joined: Nov 2004
Posts: 948
Alliance, Ohio
Valiant_Showoff
super stock
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super stock
Joined: Nov 2004
Posts: 948
Alliance, Ohio
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Quote:
.....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 switched from Flowmaster 40's to MagnaFlow turbo's 4 years ago for the very same reason. The drone at 2800-3000 rpm's was a killer.
I'm very happy with the MagnaFlow's. Pretty quiet at normal throttle or at idle, but they really bellow at full throttle
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Re: HEY!
[Re: HemiRick]
#67747
06/28/08 08:43 PM
06/28/08 08:43 PM
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Joined: Apr 2007
Posts: 1,261
ILL
mark7171
pro stock
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pro stock
Joined: Apr 2007
Posts: 1,261
ILL
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you add mufflers....2 on each side. a hot 440 needs a very large expansion area. since mufflers come 26" you need 2 on each side.
as i said before, even the stock 440 exhaust system came with two mufflers.
H pipes will make the note lower, which is part of the drone.
larger diameter pipes 3" will dramatically increase sound over 2" - 2 1/2".
Last edited by mark7171; 06/28/08 08:47 PM.
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Re: Exhaust drone....
[Re: Weldtech]
#67749
06/29/08 02:11 PM
06/29/08 02:11 PM
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Joined: Apr 2007
Posts: 1,261
ILL
mark7171
pro stock
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pro stock
Joined: Apr 2007
Posts: 1,261
ILL
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maybe its time....
expect that hotrods make noise.
youve spent enough on exhaust. with hotrods everythings a compromise.
Last edited by mark7171; 06/29/08 02:22 PM.
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Re: Exhaust drone....
[Re: mark7171]
#67750
06/29/08 02:33 PM
06/29/08 02:33 PM
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Joined: Jan 2005
Posts: 279
Pacific Northwest
Weldtech
OP
enthusiast
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OP
enthusiast
Joined: Jan 2005
Posts: 279
Pacific Northwest
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Quote:
i would try running 2 x 26" muffler bodies on each side, and see if you still drone.
try fiberglass packed ones, no hollow fully welded.
what resonator....a 26" long glasspack?
could it be road noise reflect up through the 4 speed hole? where does the most drone come from? could be also be timming, and carb tune...
Both mufflers and resonators now are glasspacks and yes are fully welded, I thought it would make a big difference over the hollow bodied ones.....
When I added the resonators there was no difference in drone at all, just changed the tone from the outside rear of the car.
The timing is right and it is tuned as best as it can be.
The drone is coming from from the rear area, can't pinpoint it that is for sure, I have undercoating on the underside and topside of the floors, Before that I stitch welded and seam sealed every seam in the car so I can't see it being a panel vibrating.... I think I am going to try stuffing insulation under the rear seat to see if it does anything!
It was suggested to try Spintechs, another hollow muffler, I just can't see that changing anything, but???? How many mufflers do I try
www.weldtechstainless.com
Where NOTHING is made in China!
70 Challenger drop top 440 4 speed R/T clone (Re-creation, Tribute, Fake, whatever...)
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Re: Exhaust drone....
[Re: 69charger R/T]
#67754
06/30/08 09:33 AM
06/30/08 09:33 AM
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Joined: Sep 2007
Posts: 14,889
up yours
Supercuda
About to go away
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About to go away
Joined: Sep 2007
Posts: 14,889
up yours
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I assume you went back thru and double checked nothing was touching anything? Only time I ever had a drone issue was when the shop overtightened a hanger and basically squished the rubber out and had metal on metal contact, was a tricky one to find.
They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
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Re: Exhaust drone....
[Re: Weldtech]
#67756
06/30/08 11:53 AM
06/30/08 11:53 AM
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Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
Clair_Davis
master
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master
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
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My Valiant kind of goes against the grain for some of the experiences & theories out there. It's a mild 340 (300hp), with 1-5/8"x1-3/4" TTI step headers in to 3" H-pipe & Super Turbo exhaust. I have no carpet on the interior of the car (leaks), and I have no drone at all. Same system on a stone-stock 74 318, no drone. The previous system was a 2" dual with cheapo turbo muffs and no H-pipe, and it had a light drone at certain speeds with the 318. Never tried it with the 340. The TTI 3" system is actually quieter on the road and deeper at idle than the cheapo system with both engines. I think it's louder at WOT, though.
The passive radiator situation could be the culprit, as my carport buzzes and hums loudly when my Valiant sits at a warm idle under it. Really strange sounding. Something like that could be going on with your car as well. I'm guessing that the window bumpers and trunk seals are in good shape and functioning?
Another issue I haven't seen mentioned is driveshaft or u-joint harmonics. I got a bad drone when I replaced my axle and the driveshaft angle wasn't just right. Adding adjustable hangers in front made that go away. Maybe try rotating your driveshaft 180* on the rear yoke and see if that does anything.
Clair
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Re: Exhaust drone....
[Re: Weldtech]
#67757
06/30/08 11:57 AM
06/30/08 11:57 AM
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Joined: Feb 2003
Posts: 1,665
Milwaukee, WI
Prince_Valiant
top fuel
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top fuel
Joined: Feb 2003
Posts: 1,665
Milwaukee, WI
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Might I suggest these:  noise canceling headphones  I jest, I jest...but seriously, in my brother's airplane, they work like a dream.
1979 Dodge Lil' Red Express - 360 rwhp, 13.2 @ 103mph
1968 Coronet: 318, 2.76, 15.2 @ 92mph! (SOLD)
1976 Valiant: 360, 3.90, 12.90 @ 106 (SOLD)
1989 Shelby CSX #500/500
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Re: Exhaust drone....
[Re: Clair_Davis]
#67758
06/30/08 12:28 PM
06/30/08 12:28 PM
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Joined: Apr 2007
Posts: 1,261
ILL
mark7171
pro stock
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pro stock
Joined: Apr 2007
Posts: 1,261
ILL
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a hot 440 and a mild 318 aint beans fer comparison.
his cam probably has some overlap, and the way cancelling mufflers work they dont cover all harmonics at all rpms.
if its that bad...seriously try minekie gold econo flo's(not a performann, but luxury) mufflers . i think they did a test and those beat all other econo SUV mufflers in sound. gabriels preimium and monroe hush-sonic had less reduction.
Y them off the collector and run 4.
my 323"(318) 4spd has 340hp cam, sp streetmiester 318 (idle-4500)intake, headers, 3.23 highway gear.
in order to quiet it, i used summit 19" glasspacks $12.99 after the collectors, and the then 19" summit $9.99 performance mufflers. no H or X.
Last edited by mark7171; 06/30/08 12:40 PM.
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Re: Exhaust drone....
[Re: mark7171]
#67759
06/30/08 02:29 PM
06/30/08 02:29 PM
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Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
Clair_Davis
master
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master
Joined: Feb 2003
Posts: 4,204
Fort Worth, TX
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Yeah, I know that, but I wasn't saying they would be the same. I never had a droning exhaust problem in my 440 Dart either, and it had 1-7/8" headers, 2.5" exhaust, H-pipe, and Sonic Turbo mufflers. Of course, it's not a convertible E-body, just a hot 440 in a hard top A-body.
With my Valiant, I was just offering a point of comparison that differed from some of the experiences stated previously. In particular, the larger=louder situation didn't play out for me, and adding the H-pipe softened the "pop" of each exhaust pulse. Since he's already gone through a multitude of pipe sizes and muffler designs, it sounds like a resonance situation with some other system in the car to me. Maybe dropping the rear gears down to 3.23 or changing the trans to a Passon OD would put the engine in a better place for cruise RPM to avoid the resonance. If we try hard enough, I bet we can spend all his money...
Clair
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Re: Exhaust drone....
[Re: Weldtech]
#67760
07/01/08 04:21 AM
07/01/08 04:21 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
maybe its time....
expect that hotrods make noise.
youve spent enough on exhaust. with hotrods everythings a compromise.
Ya, that is one way to look at it but when it is uncomfortable to drive it is no fun....
I have no problem with noise like rumbling etc (Wow is it loud at WOT with the Magnaflows!), and the fact I have put identical systems on very similar cars with nowhere near the drone has me mystified.
accurate exhaust ltd. 6 pack system.
do it, be done with it, enjoyyyyyyy........
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Re: Exhaust drone....
[Re: Weldtech]
#67763
07/07/08 08:13 AM
07/07/08 08:13 AM
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Joined: Jan 2006
Posts: 8,162
USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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a cheap way to prove to yourself that the 'science' of an exhaust system is like the 'science' of a pipe organ or flute is to buy about a 4 foot long piece of tailpipe expanded on one end, and clamp it onto your existing pipe tip. Drive around with this extension notice the drone and at what rpm it appears, then cut off six inches and repeat In a similar way if you want to use 'resonators' and don't know where to place them to cancel a particular drone/rpm buy four stainless steel pipe clamps http://www.jegs.com/p/JEGS/753274/10002/-1/11527two lengths of exhaust pipe and a resonator ...then cut and fit the resonator into the exhaust pipe section from main muffler end to exhaust pipe tip. Start with the resonator about 2 feet from the muffler end, and go about 6 inches at a time outward it is easier to just put a stainless steel, round six inch diameter, 16 inch long DynoMax UltraFlo muffler on as a tip....this will cure most drone are you good with math or have a child/friend/wife who is? {don't laugh about the wife part...it made all the difference for Albert Einstein} The basics of the exhaust noise math is here, in GM's home study course for engineering: http://www.gmi.edu/~drussell/GMI-Acoustics/Filters.html
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