[allenga]

Originally Posted by 78w72

sorry to hear you're not happy with them. keep in mind, they will get a little louder over time as the fiberglass packing gets blown out or compacted, or whatever happens to it over time, that was my experience with them.

& i'm curious how or where you spent $2500 on exhaust? pypes system is $400-500 & the mufflers are about $100. plus a few hundred for splitter tips, hangers & install etc, i'm not seeing $2500 worth of exhaust in your pic.

ceramic coated headers and three sets of mufflers with 3x install charges

[78w72]

Originally Posted by allenga

ceramic coated headers and three sets of mufflers with 3x install charges

gotcha, didnt realize new headers & 3 sets of mufflers were part of it.

[JUDGE3]

[QUOTE=Formulajones;6125891]If you have the room, the dynomax ultra flow 17546 is my favorite. 20" case so it helps subdue the sound to some degree, but they sound great, and I've never had drone issues with them.

does the 20" case fit ok in dual form under the firebird? or are you meaning the transverse muffler stock set up.

I like the soundbites I hear on the ultra flows and plan to use them. didn't find a part number 17546.

[Formulajones]

The 20" case dual mufflers would be big for an F=body. Actually I avoid that style system completely on F-bodies and go straight for a transverse system.

My 2 favorites are the Pypes setup SG70 and the slightly quieter Dynomax 89021 that uses a dynomax transverse muffler designed much like their ST muffler or you can substitute that for the ultraflow cross flow 17231.

Oops sorry typo I'm off a digit, if you're interested in the 20" case offset/offset it's 17547. I also forgot that's the one I use for 3" systems so it doesn't help those with 2 1/2" pipes.

[BAD2000TA]

So, not to hijack this thread, but I read that a lot of people like the Dynomax Ultra Flos. I replace my entire exhaust when I switched to the Holley Sniper set-up. I now have Hedman 1-3/4 headers, to a Flowmaster 815932 Scavenger X-pipe, Dynomax Ultra Flo SS #17283's, and Pypes Mandrel Bent 2-1/2" tails and tips.

The problem is that I have a terrible resonance/drone. However, it's only really bad in gear at idle. My idle is set at 750 and the sound at a light is extremely annoying. So, those with Ultra Flo's, do you have the same thing in gear at idle? I'm thinking of switching the mufflers out for the Dynomax Super Turbo #17734. Thoughts??

[Formulajones]

Originally Posted by BAD2000TA

So, not to hijack this thread, but I read that a lot of people like the Dynomax Ultra Flos. I replace my entire exhaust when I switched to the Holley Sniper set-up. I now have Hedman 1-3/4 headers, to a Flowmaster 815932 Scavenger X-pipe, Dynomax Ultra Flo SS #17283's, and Pypes Mandrel Bent 2-1/2" tails and tips.

The problem is that I have a terrible resonance/drone. However, it's only really bad in gear at idle. My idle is set at 750 and the sound at a light is extremely annoying. So, those with Ultra Flo's, do you have the same thing in gear at idle? I'm thinking of switching the mufflers out for the Dynomax Super Turbo #17734. Thoughts??

Those 14" stainless steel polished are the same set I installed on my sons mustang, with a "X" cross, and complete tailpipes, all 2 1/2". It has shorty headers.

I usually don't go for the short mufflers like this but that's the only size that fits this particular car. the only difference between yours is that mine are offset/offset. I've been very pleased with them, no drone in the car and the noise level is actually fairly tame at part throttle. It barks if you get after the throttle but cruising is very comfortable.

[BAD2000TA]

Originally Posted by Formulajones

Those 14" stainless steel polished are the same set I installed on my sons mustang, with a "X" cross, and complete tailpipes, all 2 1/2". It has shorty headers.

I usually don't go for the short mufflers like this but that's the only size that fits this particular car. the only difference between yours is that mine are offset/offset. I've been very pleased with them, no drone in the car and the noise level is actually fairly tame at part throttle. It barks if you get after the throttle but cruising is very comfortable.

So, do you think that the Flowmaster Scavenger/X-Pipe could be the cause of the drone at idle? I like these mufflers, but can't handle to the drone. The Flowmaster isn't you're typical X-pipe and I wonder if it's the issue.

I'm thinking of trying an experiment: I'll remove the X-pipe and put in straight pipe to the muffler. See if that changes the tone before I spend more money!

[Formulajones]

I've never used the Flowmaster "X" so I'm not sure how those are constructed. It might be worth trying without if it's easy enough to switch.

I've never heard of drone at idle though, unless something is rubbing, but what I think happens a lot of the time is people using aftermarket hangers that come with these kits that really don't have much rubber isolation to speak of, and then they are bolted right to the floor pans of the car using seat belt bolts. I see this a lot. So any vibration from the engine and exhaust, resonates throughout the car. I can't help but wonder if that's part of what's going on with so many different experiences here.

That's a big reason why I go through the trouble of using factory style hangers with aftermarket exhaust. They are more generous with the rubber isolators built into the hangers so they do a much better job controlling any vibration. Plus they fit like they are supposed to and hang the exhaust at the proper distances where it's supposed to be without drilling or welding on the car. It costs more, over and beyond what the exhaust will cost, but in the long run it's a worthwhile investment.

[Formulajones]

I'll show a couple of examples of factory exhaust hanger styles for a couple different cars we have here. All of this stuff (and more) is reproduced today.

First picture is the type of hanger that is used on my son's mustang. Basically it's a rubber isolator that has a hook on either end and the entire exhaust system simply hangs from this. There is a series of maybe 4 or 6 of these things throughout the car holding the exhaust. Basically the only solid point of attachment for the exhaust is on the shorty headers. This allows the exhaust to swing or move (to a degree) without bind or vibration. It's likely the reason why I can use these short 14" Dynomax Ultraflows on this car, with an X and have literally no drone or resonance.

The second picture is the type of hangers used on my wife's 69 Camaro. Again it's a circular strap material made of a mix of rubber and fiber strand and the exhaust simply hangs from it. These also allow the exhaust to move or swing to a small degree. The only point of solid attachment is again just at the manifolds/headers. Most all of your factory style hangers are designed in a way to allow the exhaust some movement, and that's done for a reason.

I can literally grab the tailpipes on these cars and move them about a 1/2" to an inch in either direction, it's not solid back there, and that's the way they are supposed to be. If your exhaust is mounted so solid that you and a couple guys can do chin ups off of it, then you're just about guaranteed to have some sort of vibration and resonance throughout the car. The cheap strap hangers you buy at the auto store, which is usually the same thing you find in exhaust kits, are notorious for being extremely stiff and really not offering any cushion or vibration absorption. Then you bolt that to the frame or floor of a car and everything is transmitted inside the cabin.

[JUDGE3]

crap. this thread has me re thinking. my experience is I love the sound of flowmaster 40's. but not the drone. I wanted a bit quieter so tried flowmaster 50's on my 69 Judge clone. real bad...made it sound like a pick up truck and when a sister in law said "sounds like a truck" off they came back to 40's. had the 50's on a month so I know what you mean on eating costs.

I am going with 2 1\2" pipe and an H pipe reading these type threads it sounds like the H pipe is a bit quieter. the dynomax ultra flow sounds good but finding out the ones i'm hearing are 20" case's on the larger Gto size cars. so now i'm afraid a small case ultra flow on a 70-81 firebird will be to loud.

there's just to many choice's now-a-days. and the car has to sound cool! back when it was nothing but glasspacks or the turbos. I don't have room or really like the stock transverse install, I like the looks of the 2 mufflers under there and don't recall any ground issues when I put duals on my 1980 TA way back in the day.

[69 Limelight]

Formulajones, seems like I remember you saying you use Dr. Gas X's in your installations. Maybe that's the common denominator in your "no drone" success especially, now that there's a post from someone about having drone even with your go-to Ultra Flows and Alenga turned out with some drone even with ST's?

[Formulajones]

Hmm,
I was just under one of the cars thinking about what I want to change.

So I 'm going to install those 20" Ultraflow 3" mufflers on my chevelle, it has a Dr. Gas X. I'm removing the 14" long Flowmaster Super 40's that are currently on the car. I like the sound but the drone on this one is pretty noticeable around 2,000 rpm.

We'll see what happens.

[ta man]

One thing no-one mentions..the Ultraflows are the heaviest built muffler with the thickest gauge steel..I wonder if that helps?

[Formulajones]

20" Ultraflows ordered. Will be here next week.

Muffler swap only on this car to see what kind of sound and drone difference we have.

The super 40's are like new. Will be for sale shortly if anyone wants a set

[Formulajones]

Dynomax Ultraflows installed. Took it for a spin. The horrible drone this car had is now completely gone. It's so much more pleasurable to cruise through town at 35 mph now. No more resonance inside the car at that speed, which subsequently always gave my wife a headache when she rode in it. She'll be happy that is all gone now.

[cnc]

Originally Posted by Formulajones

Dynomax Ultraflows installed. Took it for a spin. The horrible drone this car had is now completely gone. It's so much more pleasurable to cruise through town at 35 mph now. No more resonance inside the car at that speed, which subsequently always gave my wife a headache when she rode in it. She'll be happy that is all gone now.

Pic of the install if u would be so kind ...I'd like to see the fitment on the floor...

[Formulajones]

Originally Posted by cnc

Pic of the install if u would be so kind ...I'd like to see the fitment on the floor...

It's a Chevelle, so it's made for dual mufflers under the floor. Is that what you're looking for??

[Formulajones]

Originally Posted by ta man

One thing no-one mentions..the Ultraflows are the heaviest built muffler with the thickest gauge steel..I wonder if that helps?

They are pretty heavy gauge steel. They weighed quite a bit more than the Flowmasters I just took off, but those were only 14" long too, the new Dynomax Ultraflows are 20". I did notice that while I was welding to them I could turn the heat up quite a bit more, with more metal to work with.

The Dynomax Ultraflows I have on another vehicle are the shorter 14" version. They are also polished stainless with a slightly different case design with no visible welded seams, unlike the 17557 20 inchers I just bought which are plain stainless and welded seams everywhere.

I'm happy with both versions, neither exhibit any drone issues and they both sound pretty nice.

[Firebob]

Allenga, you want the best of both worlds? Cool at the car show and quiet when you don't need to be so cool. Boom! Here you go.
https://youtu.be/JOM7uA22Z3o

[69 Limelight]

Formulajones, do both these cars (one with 20" Ultraflows and 14" Ultraflows) have the Dr. Gas X? Just wondering, if they do, that's maybe why you have unduplicated success eliminating drone with Ultraflows. Know I had a conversation with the owner of Dr. Gas sometime back and he claimed his X's are not just 2 curved pipes with holes in them welded together, like other brands, that his have been engineered and tested.
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