Will Removing The Resonator Eliminate "Drone"?

[boonsur]

I just had a local shop replace my muffler with a straight pipe, leaving the resonator in place. I don't like it! I now have a serious drone at all rpm's. I don't think the truck is too loud, it's just the monotanous sound drives me nuts.

I'm thinking the resonator is supposed to "excite" at a certain frequency and cancel out other noises. I'm wondering if this is causing the droning sound. Will removing the resonator fix this problem, or just make things worse? Has anybody been down this avenue?

I'd like to get this figured out before the wife has to ride in it - she'll kill me!

 

[jthorpe]

I know this isn't helpful for your situation and for that I apologize, BUT, your wife sounds a lot like mine. I won't straight pipe my rig for the very reason that she would never ride in the thing again!

Oh wait, maybe that's a good reason for me to go ahead and do it.

 

[boonsur]

Yea, but my wife drives a minivan. Sooner or later, we'll probably take a trip where driving two vehicles doesn't make sense, and I refuse to let hers become the family car.

HELP! You can see my urgency!

 

[Evan A. Beck]

Try removing the resonator, and install a piece of straight 3" pipe. The drone should go away. #ad

 

[Sean Flanagan]

I heard that removing the resonator will make the drone louder! Havn't tried it though. With just the muffler out, I can't tell much difference in the cab from before when it was in (with the windows up) Maybe some drone at about 2000rpm.

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98. 5 2500 QC LB 4x4 5spd, white. Pathfinder ATR 285x75x16
Cummins 24v w/ TST PowerMAX w/EGT and Boost gauges on A-Pillar. VanAaken CPC. K&N In the factory air box. Stock Injectors, Stock Exhaust (Geno's Muffler Eliminator). Re-routed breather stink tube, 2WD-low kit, Stewart-Warner Fuel Pressure Gauge, SnugTop, JJ Stainless Running boards, Tow Hooks, Bushwacker Street Flares, and a Cup Smoothie.
95,000 miles (5/10/01)

 

[Hyper]

where are these resonators at??? My truck has a muffler and a cat... no resonator!

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1993 Dodge Prostock Daytona 7:70@172, 1987 Grand National 11:77@115, 1996 Dodge Ram 3500 Dually. Stock with a 5 speed, Home page http://www.home.earthlink.net/~whra3

 

[joesoot]

Hyper-
your truck does not have a resonator as it's a 12valve, after 1998. 5, the development of the 24v head the engine didn't need a cat to pass fed emissions. But I guess the noise emissions were a bit more dB at certain rpms on the 24v therefore ma mopar added the resonator.

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2001 2500 4x4 ETH/DEE
3. 55 LSD, Straight pipe.

 

[1tuffram]

I agree with Evan, you might have to do a little experimenting to eliminate the drone. If removing the resonator does not solve the problem you might look into putting one of those "straight thru" type after market mufflers on. I've heard they take care of the straight pipe drone problem and is only a little quieter than a straight pipe exhaust.

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'95 2500 SLT 5 speed 4x4

 

[Hyper]

thanks joesoot... I now understand. . whew thought I was missing something

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1993 Dodge Prostock Daytona 7:70@172, 1987 Grand National 11:77@115, 1996 Dodge Ram 3500 Dually. Stock with a 5 speed, Home page http://www.home.earthlink.net/~whra3

 

[boonsur]

What do they sound like with no resonator, but with a muffler?

My next step may be to try getting rid of the resonator, but I have nothing but regret for getting rid of the muffler. I'd hate to be buying a new muffler AND a new resonator in the near future.

Now that I plan on getting a new muffler, I need some help deciding. Should I go up to 4", or just get a 3" and be back to square-one? I want a little rumble, but right now I'd be happy to have "quiet" back :-(

 

[big barney]

I got rid of the muffler and resonator and replaced it with a walker 21468. It sounded terrible. There was this high pitched whistle sound at all rpms that would drive you nuts. It was really bad when I up shifted. I put my stock muffler on a week later. I recently added the Jardine 4" and couldn't be happier. It seems queiter than my stock system.

 

[Great White]

I went to West Marine and purchased a sheet of marine sound deadning foam 1" thick. This was installed glued to the inside of the cab behind the rear seat. Seemed to make a significant reduction in sound. Next was Thermo-tec tape wrapped around exuast pipe from turbo back to rear of cab. Again some noticable improvement.
I am waiting for Marco's MAD ECM then the "BOMBING" will begin. After the mod's are complete then off to ATP's shop in Anaheim, Ca. for complete engine blanket install. There have been posts regarding engine blankets and their effectiveness. one of the noisiest locations on the engine appears to be the bottom near the pan. Sound levels have been tested at 110Db... . So I intend to make an effort to obtain some "deadning" material there also.
After 20+ years of sound exposure I have significant hearing loss.
Check older threads and many people have found ways of reducing noise (or increasing)!

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2001. 5 2500 ETH/DEE 4x4,Patriot Blue over Silver,Camper pkg, Trailerpkg,3. 54LSD, Agate Leather,Stainless Smitty Bars,Tow hooks,Amsoil,Window Fix... ... ... Except snowplow!

 

[boonsur]

I had thought about better insulatation for the cab. In my car stereo days, I used to use carpet padding (thickest available) to line my boxes, etc.

How hard is it to remove the back of the rear seat (quad-cab)? It's cold and raining here, so I'm not really in the mood to play with the truck today. I figure I'll be shopping mufflers next week.

 

[big barney]

I installed a complete turbo to tail pipe system. I got the bigger muffler, not sure of the make. It sounds a little louder when you get on it, but just crusing down the freeway it seems quieter.

 

[johnwen1]

I replaced my muffler and resonator last week with the Walker and I can't stand it either. It also has a very annoying whistle coming from it and it's awful sounding. I'm thinking of going with the Flowmaster and see if it's better. Anybody tried the Flowmaster and if so, how does it sound?

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99 QC 3500, Automatic, 3:54 LSD, "Big Ole White Truck", PE EZ, DTT VB & TC, Chrome bed rails, Nerf Bars, Billet aluminum grill and fog light openings, stainless bug shield and eyebrows, billet aluminum "RAM" third brake cover. Amsoiled.

 

[Kodiak]

johnwen1

I had a Flowmaster 3-chamber for about a year, and it had more resonance that the Walker I have on now. It was also more restrictive, judged by EGT and boost behavior.

The Walker ain't thrilling me either, though. The 2K resonance is downright invasive, so I'm looking...

Flowmaster has just come out with a kit for diesels pickups that is comprised of a resonator and 2-chamber muffler into a 3. 5" tailpipe. From my recent experience, I am personally a little bit leery laying down the bucks they are asking for this, but, on the other hand, I think they are considered by many to be the best exhaust R&D in the industry.

If you do go the Flowmaster route, please post your opinions.

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'95 2500 CC, SLT, LB 2WD, auto 3. 54, 74,000--Westech gauges in Autometer pod, Prime-loc, Brite box, Back-off Box, White Night back-up light module, Line X, Walker muffler, Borgeson steering shaft, Geno's Crankcase Breather/Vent Tube Catch-All

 

[boonsur]

From the sounds of it, the best setup for a 3" exhaust is probably the stock system. I will not get the desired rumble until some, or all of it is 4".

I also remembered an old co-worker who left to go to a company that manufacturers mufflers. I believe the name of the place is Bentler Industries in Grand Rapids, MI. I think I'll look him up and bounce a few ideas off him. Might be good to have an "expert" opinion. Maybe there is a way to "tune" the pipes for a better sound.

 

[boonsur]

Big Barney, did you do the complete system in 4"? Which muffler did you get with the system?

Quieter is better, but I expect the 4" will give a deeper tone. I'll probably end up with a 4", I'm just not sure how far up the system I'll go.

 

[David_VT]

Seat comes out real easy! I pulled mine to do some wiring in the cab so I could roll the carpet up. This is a no brainer, just take your time figuring out the bolts and then lift the entire seat out! No need to take the seat apart or anything radical like that.

I have a roll of eve guard (the rubber for the edges of a roof) and some spray adhesive. This summer's project is to get the rubber on the back wall of the cab to help with the lack of insulation there.

 

[dmurdock]

Boonsur, check to see how "loose" your exhaust system is after the replacement. I had a local shop do the same thing to mine, and I have no drone at any rpm. However, this is an old school shop (they bend all their own stuff and weld everything). The new pipe was welded in and he put new hangers in the brackets (which he made out of stock), pushed the exhaust system up until it was real snug, and then welded the hangers on while another guy held the system up. I think the droning is most likely caused by oscillations in the whole system. Before you try to hide the noise, try to eliminate it. I'd try some (gasp!) bailing wire wrapped around the exhaust and then around the frame (or something) to hold the system real tight (keep from moving). see if that works