I've got about 500 miles on my single Street-pro and it drones at around 2000 RPM or about 70 MPH. If it doesn't mellow out by the end of April when I go on vacation for two weeks, it's coming off and the stocker is going on for the trip!
57 Heavy

 

I thought Drone was that RICEY Sound ? After 2k Rpm or so

 

Nope. More like a constant "ooooooooooooohmmmmmmmm" sound

 

You said the guy welded a 1 lb. piece of metal on the back top side of the muffler. Do you mean it was installed on the top part of the muffler can? Or was it installed on to the pipe going in to the muffler?
The stock mufflers on the V6 single exhaust have a damper welded to them on the back end of the tip or exhaust side of the muffler.
As I recall the damper is a hollow metal tube with rubber fused inside of it.
I wondered about doing this to my Street Pro mufflers before I decided to replace them with Flowmasters which don't drone.
Both are chambered mufflers. One drones and the other doesn't.
The Street Pro is stainless all the way through and it drones.
The Flowmasterhas apainted can and only the exhaust tip is stainless and it doesn't drone.
Hmm.
I doubt the paint can make any difference drone wise. Must be the baffling inside.
Neither of them have the external damper as with the stock muffler.
If a 1 lb. piece of metal isattached to the can, that will change themuffler's resonant frequency where the main body is concerned. It will push it up to a higher frequency that should suppress the drone. Makes sense. I suppose that if it drones at all after that then it would be only at a higher frequency that would not tend to permiate the driver's environment with that awful ear pounding drone.

 

Hi Wolfey,

Wouldn't adding weight to a muffler increase its weight and correspondingly decrease the speed of vibration? The added weight should lower the harmonic frequency of the vibration of the muffler.

However, I understand "drone" to be the actual compression of the exhaust flow, which, with low restriction, should not make the muffler physically move much. Equal length pipes create the drone as the 2 sides mirror each other in tone. Resonators added at different spacings break up the similar pulses, and reduce/eliminate drone.

I'm getting my Pypes with Street Pros next week, so I'll be in the same boat as GstangT.

However, I also remember your comments Wolfey, and opted for the GT Appearance package which also includes 2 GT mufflers to go with the bumper.

That will be my option #2.

Oh, GstangT, question: Does the drone HAPPEN at 2000RPM or START at 2000RPM?

Just want to know if going faster eliminates drone or just ruptures your eardrums...



I'm game for both, just sick of the stock can...

I used to run a 429CJ so I don't mind the drone so much. That 429 on a long cruise (3" pipes) used to play Hell with your bladder!!

Good luck!

SOHC

 

It STARTS at 2k rpm, so the more u push, the louder it gets! lol, but I may be somewhat used to it by now, but sometimes I still don't like to hear it.

 

Can you make a short video from inside your car?

I'd like to know what to expect next week.



SOHC

 

I would, but I don't have a dig. camera right now or anything to record it with. But I don't think these videos show how it really sounds in real life..

 

I had and MRT and hated the drone it drove me nuts and dd sound ricey. I went to a GT take-off and to me it sounds great NO drone,quiet at cruise but when you hit it it sounds great!

 

429CJ, oh those were the days eh? ;-)
I had a 68 Challenger, a 69 Charger RT, aRoad Runner and a 68 Mustang 289 Hipo from my teens up into my 20's,all monsters in their own right. Wish I still had em!

In theory and in practical application as well, adding a weight to the side of the can doeslessen the drone because it increases the overall frequency of the can's natural resonance. Take a string about a foot long and stretch it, flick it with your finger and listen to the tone it generates, now shorten it and do it again. You'll hear the tone go up / frequency increase. Same deal with the weight on the can.
The weight simply decreases the can's ability to vibrate. That's litterallyor physically what happens.

If the manfuacturers used a thicker/stiffer material for the cans then we'd have no issues with drone in any case. However, there is still the problem with pulsations moving up and down inside the pipes and the cans.

The baffling in the can takes care of that or tunes it and the resonators in the pipes take care of that mess. There's only so much that can be done before one starts adding too much restriction to flow.

But in our case, the can's are the main culprit. I do feel that if the cans were farther up toward the cat's, we'd have no drone issues at all. The exhaust might sound better too where that meatymuscle car sound goes ;-).