Drone comparison

[Sixtyeight]

Hi,

I'm in the lucky position two own 2 Chargers, a 68 and a 69. Both with a fresh rebuild 440 engine. One sounds absolutely fantastic and the other one has a drone from hell in it...

This is the difference in set up:

68 = headers / 2.5 RVS pipes / No H-pipe / Flowmasters Delta Flow 40 = sounds fantastic...no drone whatsoever
69 = Original stock HP manifolds / 2.5 standard pipes / H-pipe / Flowmasters Delta Flow 50 = heavy drone in the car...

According to the experts the Flowmaster 50 should have a lesser drone instead of a bigger one, and the biggest difference are the headers or the H pipe, or the combination...

Who knows the cause of this difference in drone sound?



Thanks
Jeroen.

[c00nhunterjoe]

They will all drone at some range. Its a combination of the specific engine build, load, gears, and sweet spot rpm.

[Sixtyeight]

They will all drone at some range. Its a combination of the specific engine build, load, gears, and sweet spot rpm.

As said, the 68 has no drone whatsoever...

Jeroen.

[cdr]

are the distributors set up the same, timing,vac adv, ? late ign timing can make the exhaust loud & drone.

[Sixtyeight]

Yes settings about the same...

Jeroen.

[c00nhunterjoe]

I have never seen any brand 2 chamber muffler that did not have a drone of some kind. As i said, you are just not in the sweet spot in your driving habits. Thats not a bad thing. The reason you only experience in 1 of your cars given identical engines is because you have 2 totally different exhaust systems on the exact same build.

[Just 6T9 CHGR]

Both engines have the same cam, compression ratio, carb etc?

Usually the H-Pipe will help with resonation but it looks like this is not true in your case?

[don duick]

one engine may have  a better balance. I had a really bad drone that was caused by a converter that was out of balance or wrong for the motor.

[JR]

I have no idea, but I can tell you back when I had HP manifolds, 2.5 inch exhaust with H pipe, and 40 series Flowmasters with no resonators, the drone was awful.

I got fed up with them one day and put a stock style muffler back on, and all the drone is gone. I have shorty headers now, and still no drone.

Just hearing the name "Flowmaster" sends me into a nervous twitch, I'll never buy another set of them again.

I know this isn't a helpful post, but it felt good to get that out.

[BSB67]

I think there are a set of conditions, both car (weight, gear, converter, cam...) and exhaust related that will make the drone condition better, or worse.  However, everything else being equal, I think that manifolds always worse.  If you use a Dynomax 17747 muffler the drone will either disappear, or nearly disappear initially.

[TommyGun]

On my 68 with 440, when it had manifolds it had a bad drone. Couldn't talk at all or hear radio. I changed to headers and now it doesn't drone at all.

[bsakal]

If you use a Dynomax 17747 muffler the drone will either disappear, or nearly disappear initially.

I had a set of the Dynomax 17747 on my 69 Satellite with a built 383 and HP manifolds, droned like crazy. I took them off and put on AP 6493 mufflers (they are their Big Max Turbo mufflers, long case with dented corners like the hemi muffler), and the drone was in a different range. I added a pair of 4 inch round AP mufflers as resonators like the Hemi cars had - drone gone. The Dynomax 17747 also droned on my stock 66 big block Newport.

[Kern Dog]

It is the manifolds, man....No matter what people say, they are like trying to empty a pool through a garden hose compared to headers.

[Challenger340]

Very little to No Drone at all, almost to the point you wouldn't know the Engine is "on" when driving unless you roll the windows up/turn down the radio, very quiet.

'69 R/T SE, factory original Manifolds/H-pipe/Tailpipes, 2 new "correct" style resto mufflers 6 years ago.

[Sixtyeight]

Tried the Walkers Sound FX now on the one with the drone.... Drone gone, but just because they really are silent mufflers....

I think I agree with Kern Dog...I believe it´s the manifolds...if you want a louder open chamber muffler, I think you also need the headers.


Jeroen