[64speed]

The guy that had my car before me put brand new exhaust on it with flowmaster copies which I think are thrush. To make a long story short the drone is horrible at cruising speed. I am tempted to put regular quiet turbo mufflers on it it's so bad. I will have to redo the exhaust when I install the new motor and headers etc. down the line. I just want to quieten it up right now. Will an h pipe help?

[tom s]

a H pipe cured the drone my car had at 2K with a X pipe.Tom

[OCMDGTO]

Neither H nor X worked for me(2 1/2", RA manifolds) but Dynomax VTs helped reduce but not totally eliminate the dreaded 2000 rpm drone.

[cmk-2]

That's what I have on my 1978 W72 T/A with auto. RA manifolds an X and 2 1/2 exhausts with the Dynomax VT's. Really helps ALOT with the drone.

[fiesta62]

I had the gardner system on my 67 gto and zero drone, looking for more power i installed 2.5 inch Pypes system with X pipe and race pro mufflers, maybe mild power increase but definite drone very annoying ,
then bought some magnaflow mufflers as many said they don't drone, bollocks no different to the race pros they all droned, I tried attaching weights to the system here and there as some suggested but this did nothing,
then I bought dynamax VT mufflers and the drone is about 80 percent gone, I have to listen and concentrate to hear drone now its so mild its not a issue really, the VT are real quite cruising but stomp on it and the door inside opens to give a nice muscle tone,
its very hard to tell but there is possibly a very slight loss in power compared to the race pros or magnaflows, but they are louder so it may just be the louder sound that make me think more power, bottom line don't waste money and time looking for a fix, just buy some dynamax VT'S

[lfdsteve]

I like the vt's fwiw

[Tfisher15]

VT's worked on my Firebird.

[rohrt]

I researched the drone issue to death reading hours of archive data and noting the results.. I could never find much consistency on why some cars drone and others didn't. However there was some things that made them more susceptible to having drone issue. #1 was the drone master mufflers (including any strait through design muffler). #2 was X pipe install.

VTs did solve the issue on my bird. I went from a straight through muffler to a 14" Dynomax ST then to the VTs. The ST mufflers helped alot but not enough.

Its never fun just throwing money at something and then just crossing your fingers. The nice part about the A-bodies is you can use a longer case mufflers, this will give a better chance of eliminating any drone. My brother has Ultra flows on his 66 GTO and it sounds nice. I love my VT's too. Nice and quiet at idle and opens up nice at WOT.

[64speed]

I didn't have this problem with my previous GTO's so I know it's just this particular muffler brand. My little 2 barrel 326 sounds like a monster at idle and just gets worse as you drive. Does anyone have a recommendation for economy mufflers cause I plan to do a full exhaust when I do my engine swap but I have to quiten it down now.

[A.J.]

Just a thought, would there be any difference in drone between the material used in pipes and mufflers. For example is stainless much harder than carbon steel and could it due to this maybe add drone or resonace?

[sts]

I recall reading somewhere that hangers can cause drone. The ones with the rod-in-rubber reduced drone. I read it on the internet, so take it for what it's worth

[fiesta62]

been there now done it all asked everybody, its plain and simple just install vt's problem solved....

[Formulajones]

I have various cars here with drastically different exhaust systems, using Flowmaster, Dynomax, and Pypes, in different sizes with "X" and "H" pipes.

From what I've experienced the biggest changes in sound and resonance comes with muffler changes, not so much the style of cross over.

The last 4-5 years I've become more of a Dynomax fan. I've had more consistency with these mufflers and pipes in sound quality, with great sound and no drone to speak of. Never tried the VT's but I've had a couple sets of Dynomax Ultraflows on 2 cars with no drone issues at all. I've really grown to like this muffler, great flow, love the sound, yet very tolerable, almost docile, on the highway.

[FrankieT/A]

I'm trying these in the 3 inch version...Power Sticks

http://www.classicchambered.com/classic/products.html

I'll report back...but it's going to be about a month to get my engine back in.

[Formulajones]

Hehe, those will be LOUD. You won't have to worry about drone with those, because they make so much noise anyway.

Buddy of mine used those on a Yenko Nova build, thought he could mimic the factory Chamber Exhaust that GM offered back then but do it in a 3 inch system. Sheesh that thing was loud EVERYWHERE, and when he stood on it the car could be heard for blocks, lol. Talk about a cop magnet.

Even the factory style reproduction chamber systems that are offered today in small 2 1/4" piping are pretty daggum loud, and they even have no less than 4 of those sticks integrated into the system. Thought about installing the factory chamber setup on my 69Z, but it's just too noisy.

[FrankieT/A]

Well, I checked out the videos, and ruled out anything late model that could possibly have cats. They have one of a Durango showing the underneath, no cats and doesn't sound too loud. They look to be the 26".

Here's my thought, I'm putting on a 3.5 X pipe. I'm going to cut the legs off of it and install their 3 inch X 40 inch long Power Sticks thereby eliminating my Dronemasters. I realize the 3 inch power sticks will be louder than say 2.5, but I'm hoping the 40" length will help. The only reason I'm considering this is they seem to be the free-est flowing. I won't consider the VT's because I don't want apparatus in my muffler. After a while that has to fail because of corrosive exhaust. Either they won't work after while or an axle (for lack of a better term)will break. Inside a muffler is a hostile environment. Same reason I won't use a muffler with a packing, they ultimately blow out. Either way I don't want buy another set mufflers in they future. That's the one reason I like Flowmasters...they last forever...

[Formulajones]

If you don't mind the noise they make then definitely worth a try for you.

In late 68 GM issued a recall on the Chamber system for noise complaints, (early on it was standard issue) but because of the complaints the system was made "optional" around October 68, and by May of 69 the system was removed from the option list completely.

The 40" long power sticks were used on my buddies 3" system. It was really loud. It also had the typical Chamber style cackle sound. If you don't mind that they'll serve you well.

I agree with you on the VT's. There is just something about having moving parts inside a muffler that doesn't interest me in the least. That will eventually fail. I tend to think it will either stick in the open or closed position, or just fall apart all together. Might take a few years, but just not something I'm willing to experiment with considering the cost.

[FrankieT/A]

I think ultimately it's going to be a "crap shoot"...

[FrankieT/A]

What I am really looking for is that 180 degree header sound. Ground clearance with 180 degree headers is a major issue. I don't know enough people with different types of mufflers to listen to to make a decision. Video of sound, if that makes any sense, is not to me accurate enough.

[tom s]

I think the only way to get 180 sound is to do 180 headers