[Formulajones]

I'm running a set of Dynomax Ultraflows on one car, small case offset inlet and outlet, 2 1/2" with an "X" cross over and tail pipes, and a set of headers up front.

No droning on that one. Actually it's very tame at cruise and requires 1/2 throttle or more to get any bark out of it.

[ta man]

https://photos.google.com/share/AF1Q...RzYmhYUmhhVTRR


3inch Ultraflows cruising down the highway, 1 3/4 Hooker Headers ,3 inch tailpipes, dynamat on the floors..high 10 second car with 308 gears

Speedo reads 10 percent high

[allenga]

Originally Posted by moontower69

The Dynomax Ultra flow will still drone.

Get the #17749 DM super turbo (offset/offset) with 2.5 pipes and it will rumble like stock muscle from 70s and still roar a bit when you mash it down.

Its the only way to go if you value your ears, sanity and want to be comfortable on long trips talking to people in your car or on phone.

You are right. Dynomax Ultra flows that I just put on the car drone

[Formulajones]

What's the rest of the setup?

I love the Ultraflows, my favorite go to mufflers. I 'm using them with a full system, tailpipes, 2 1/2" throughout, with an "X" cross over and a set of headers.

No drone at all. Very comfortable to cruise. Even wide open throttle isn't that loud inside the car.

[allenga]

Originally Posted by Formulajones

What's the rest of the setup?

I love the Ultraflows, my favorite go to mufflers. I 'm using them with a full system, tailpipes, 2 1/2" throughout, with an "X" cross over and a set of headers.

No drone at all. Very comfortable to cruise. Even wide open throttle isn't that loud inside the car.

Pypes 2.5in, X pipe, Hedman Street Headers, full duals, tail pipes.

I also have vibration transmitting up through the console and shifter. Nothing seems to be touching the car.

[OCMDGTO]

Allenga, I feel your pain since I've had at least 5 sets of mufflers on my car over the years trying to quiet it down. One thing I didn't see you mention is your power level. If you are stock I'd try a long case Dynomax ST. Only reason I never tried them is their sales rep said they start restricting power around 375hp. Best ones I ever had on were Dynomax VTs which still very slightly droned but are now unavailable

[allenga]

Originally Posted by OCMDGTO

Allenga, I feel your pain since I've had at least 5 sets of mufflers on my car over the years trying to quiet it down. One thing I didn't see you mention is your power level. If you are stock I'd try a long case Dynomax ST. Only reason I never tried them is their sales rep said they start restricting power around 375hp. Best ones I ever had on were Dynomax VTs which still very slightly droned but are now unavailable

Thank you Sir. I have a stock W72. Interesting. Prior set up. When I had factory exhaust manifolds, duals with no X pipe and Flowmaster 40s, no drone or vibration.

[moontower69]

You're gonna keep chasing your tail trying different recommendations of folks here to "tweak" your muffler set up (X v H pipe, etc). Most of the folks here dont drive their cars daily. If you do, there's no really good drone free option but the Super Turbos - best balance between sanity and power and decent sound.

But just put the Dynomax ST long case mufflers in and problem solved. PERIOD. And they DONT rob power at all unless you're worrying about a tenth of second on the quarter mile race times....I think Jim Hand tested them and showed they dont really rob power at all unless you're making 500 HP or more....

[69 Limelight]

I too am one of those who have chased my tail trying to get rid off drone. Swore I was done and just going to live with it. A member on here got a stock reproduction system from Inline Tube. It came with two different length mufflers. Obviously the factory put a shorter muffler on right (passenger) side for some reason. Has anyone that's been chasing this drone issue tried two different length mufflers of same kind. I currently have 18" Race Pros and since they're available in 14" I may give it one more try, sometime in the future, unless someone has already tried it and responds negatively on here.

[burd]

Borla SS lifetime mufflers. The best.

[Firebob]

To do this right I think there would have to be some sort of std testing guidlines( never gonna happen) like decibel level at so far from the back of the car,. Also inside and out. Drone is some else entirely. It will have everything to do with hp, size of pipe, components used and design of the exhaust system.

I have had my UltraFlows on for about 10 years now. Currently behind Dougs headers, X pipe, and tailpipes, all 2.5 inch pipe. I get no noticeable drone at any rpm. It's a bit loud inside and will wear on you after a few hours of constant driving but I think it sounds great. I'd buy them again.

https://youtu.be/eaWBd3M9MN4

[moontower69]

In theory different lengths can help with drone at the MARGINS because its like a tuning fork if they're the same length. A shorter muffler helps (at the margins) keep it from resonating back and forth at exact same wavelength.

That could be why factory did it (or to save money, who knows for sure?)

But a 14" RacePro and 18" RacePro won't matter one crap towards helping with the dreaded drone (those muffler are definitely louder than Dynomax STs and drone to varying extents depending on setup).

That's my experience after lots of ringing ear drives.

[allenga]

I'm going to try one more set. Thinking Hooker Aerochambers. ?

[tom s]

I put a set of STs on my 69 bird.Have a H pipe and no drone but they are louder than my Hushpowers at cruise.A little more quiet at idle for the STs but not at cruise.The bird is going in for custom headers on the RA V and im thinking of putting the Hushpowers back on.BTW they are made by Flomaster.Tom

[ta man]

Each engine combination itself and cruising rpm can cause a drone at certain speeds.

[Formulajones]

We daily drive our stuff so I'd never hear the end of it if we had a bunch of stuff that droned.

We have various different types of exhaust on the cars, some I've modified further from what is offered. A couple cars I've had several systems on over the years until I found something I was satisfied with.

I have 2 F-bodies, both of them daily driven. Both use the Pypes transverse system with a cross flow muffler that Pypes says is patterned off of their race pro design. One F-body is a Pontiac with RA manifolds, X cross, etc... It's not overly loud cruising, it does make some noise at WOT but it's not horrible. There is no drone with it.

The other F-body uses the same Pypes transverse system, with Dougs headers. I didn't have drone but it was a little louder at all levels than my wife wanted. I didn't like the tailpipes from Pypes on this particular car anyway so I removed those, grafted in a pair of 2" factory tailpipes that are reproduced for the original system. This tamed down the sound at all levels and actually made the car a little more quiet than I prefer, but my wife is very happy with it, and it gets compliments on how it sounds all the time. It's not even close to producing any drone and is so quiet inside the car that if I really want to hear the engine I have to roll the windows down. Wife drives it every day.

My sons mustang runs the Dynomax Ultraflows and it's not all that loud anyplace. You have to romp on it pretty good to really wake up the exhaust, but at cruise it's very comfortable, no drone, he drives it daily to and from college.

I do have one car that drones horribly at 2,000 rpm. But it's a 3" system with 3" tail pipes from Torque Tech, and Flowmaster super 40's, with a Dr. Gas X pipe, 2" hooker super comps and an engine making 600hp. It's just loud all the time. I don't drive this car that frequently these days, I've grown tired of the noise. It will get a pair of Dynomax mufflers in the future to tame it down just a bit.

Oddly, dad's car with over 700hp and a much larger exhaust system with race mufflers that can't be any longer than 10-12 inches, doesn't drone at all and for what it is, it's surprising how quiet it is inside the car. Easily carry on a conversation and it's another one that with the windows up, it's very comfortable at cruise and quieter than you would expect.

Just goes to show that a well designed system with the right mufflers can tame down even a large amount of HP on the street. They don't have to be horrible to drive if you're willing to experiment and find what works for you.

[Charlie Brengun]

Originally Posted by allenga

I'm going to try one more set. Thinking Hooker Aerochambers. ?

For what its worth.. I have a flowmaster exhaust kit with h pipe on mine and it uses aerochambers instead of flowmaster mufflers. I have not noticed any drone and am happy with the sound of the aerochambers but i have to admit i have not driven the car much at all...

[Formulajones]

I'll add some more. I've used all kinds of stuff like Spintech, Magnaflow, 4 different types of flowmasters, Dynomax Ultraflow, Pypes race pro and street pro, as well as the Dynomax turbo style mufflers.

I used a dual system with race pro and street pro mufflers on the same truck, just swapped the mufflers, and I can say without a doubt the street pros were quieter at every rpm level and produced no drone. I did not like the race pros at all, they were just loud everyplace and they quickly came back off.
I even tried a pair of Mac mufflers, don't know if anyone remembers those. I don't think they are made anymore. They were pretty loud too and I grew tired of those after a few months, they came off.

One truck I ran a BBC with hooker headers and 3" dual exhaust with no cross over at all. Full tail pipes. When I had flowmaster 2 chamber mufflers on it, it was obnoxious and sounded like 600 hp was coming at you. Just absolutely ear bending. Wife hated it. All I did on that one was simply switch over to a pair of Pypes street pro mufflers and it completely transformed that truck into a very nice rumble, completely quiet at highway speeds, no drone, and she then daily drove it for a couple years without a single complaint.

[allenga]

Originally Posted by Formulajones

I'll add some more. I've used all kinds of stuff like Spintech, Magnaflow, 4 different types of flowmasters, Dynomax Ultraflow, Pypes race pro and street pro, as well as the Dynomax turbo style mufflers.

I used a dual system with race pro and street pro mufflers on the same truck, just swapped the mufflers, and I can say without a doubt the street pros were quieter at every rpm level and produced no drone. I did not like the race pros at all, they were just loud everyplace and they quickly came back off.
I even tried a pair of Mac mufflers, don't know if anyone remembers those. I don't think they are made anymore. They were pretty loud too and I grew tired of those after a few months, they came off.

One truck I ran a BBC with hooker headers and 3" dual exhaust with no cross over at all. Full tail pipes. When I had flowmaster 2 chamber mufflers on it, it was obnoxious and sounded like 600 hp was coming at you. Just absolutely ear bending. Wife hated it. All I did on that one was simply switch over to a pair of Pypes street pro mufflers and it completely transformed that truck into a very nice rumble, completely quiet at highway speeds, no drone, and she then daily drove it for a couple years without a single complaint.

Interesting. Pypes web site says street pros are louder than race pros. Looks like street pros are just a hollow muffler.

[Formulajones]

Originally Posted by allenga

Interesting. Pypes web site says street pros are louder than race pros. Looks like street pros are just a hollow muffler.

Yep, and I've never understood why their site says that because I've never found that to be the case at all. I've swapped them on the same vehicle with no other changes and the street pros are absolutely quieter in every respect.

I had a 72 blazer with a 6.0 LS swap, used the LS truck manifolds, and then I built the exhaust system from there. Used an H pipe, all 2 1/2" piping, and full tail pipes to the rear bumper. This was a daily driver so comfort was priority.
I first tried a set of Mac mufflers on it that I had laying around. It was a bit too loud for my taste. I knew I didn't want flowmaster on this thing so I went straight for a pair of Pypes race pro mufflers. They were louder than the Mac mufflers and also droned. They were just loud everyplace, low throttle cruise around town, idling, highway, and got even louder at full throttle. They just weren't going to work.
I bought a set of the street pros, same size, and installed them. Immediately on start up the idle was tame with a mild rumble. That same mild sound was present at light throttle cruise around town and highway was almost quiet, no drone, and best of all I could now carry on a conversation with passengers in a fully open passenger compartment. They did growl a bit at full throttle with a bit of cackle which was fine with me, so it made a little noise when you wanted to.
That's when I pulled the flowmasters off my other truck with 3" exhaust and bought a set of street pros for that one as well. Again it was a complete transformation and my wife was happy. I've never bought another set of race pro mufflers, and don't plan to.