Dynomax Super Turbo Mufflers " 17747

Anyone have the Dynomax Super Turbo Mufflers " 17747 on their car ?





Im looking for feedback. Ive listened to some cars with them and so far so good. That said, none of the ones Ive found were hemi cars or even big block mopar cars . Mostly small block A bodies and some GM cars

My car has old Year one repop hemi mufflers from 20 plus years ago,,,. and quite simply,,,are too quite. And Im looking to upgrade without getting obnoxious.

Pretty sure I had them on my old Hemi car - full 2.5" system, modified the tips to take 2.5" in - and they were crisp, fairly loud @ full throttle.
That car sounded great, and like it meant business.
Have them on my '68 383 car, otherwise stock system, no tips (base model RR), much quieter no matter what.
The 383 has less CR (9.5 vs the Hemi's 10.8), which does flatten the tone, so to speak, not as crisp-sounding.
My '69, with more CR (actual NHRA spec) but replacement stock system with tips, and a slightly bigger cam than the '68, sounds great, more like my Hemi car.
Tailpipe size matters for decibels, as you likely know; and '68-'70 cars with the factory tips always sound better to me.

You might try the straight through "turbo" mufflers - sounded good on Engine Masters, and IIRC, less loss in HP than the U-turn architecture.
I don't recall if they have a welded case instead of the stock or stock-ish crimped style.

Bill are your "hemi" mufflers like this with center in and offset out, a perforated inside pipe?

The Dynomax Super Turbo Mufflers 17747 and listed as the quietest of the bunch?? I had the Ultra Flo SS polished on the '68 RR and really, really liked them. For what it's worth I currently have the Flowmaster chambered mufflers Series 40 on the '69 GTX and they are TOO LOUD and they have it terrible, terrible resonance right at normal cruising speed (4-speed/3.54) and my wife can't stand it....I guess that's why I haven't changed them to the Dynomax Ultra Flo SS that are new and sitting on the shelf . IMO you might like the Ultra Flo welded as they are even louder than the Ultra Flo SS and for sure louder than the Super Turbo's.

One thing I can't understand is why the "welded" Ultra Flo (bottom or last image) is listed as "louder" than the, what looks to be the same internal design, Ultra Flo SS polished muffler (first muffler image)??

#1 muffler image = Ultra Flo SS Polished

#2 muffler image = Super Turbo 17747

#3 muffler image = Ultra Flo Welded

Mike

Bill another not so good thing about the Super Turbo muffler is the "flow rate" as compared to the Ultra Flo and the X, BIG difference!

https://www.dynomax.com/mufflers/

Ok so if you are taking. About super turbos, I had them on an e body and maybe was what I had on the last 69 rr. They were what I’d call a generic street performance sound. With the heat riser blocked, they drone around 2500 rpm. You might want to run some sort of little resonator. I had an x pipe on the challenger, an h on the rr.

I’m thinking of getting repop hemi muffs from accurate and running factory style resonators to factory style tips on the GTX. I’m tired of the ca turn down bs.

Were they the short case super turbos ? I have those on my 69 383 dart , no H pipe , full 2.5" system and the drone is horrible , I have the mufflers Bill is asking about but haven't installed them on anything yet. I'm going to switch to the Ultra flow and probably put an X pipe on the Dart .

I have them on my 'Cuda. First behind the 500" wedge and now behind the 540" Hemi. Typical glass packed muffler; they get louder over time (years) and the drone is noticeable. But the drone is easily addressed by putting any cheap glass pack (bullet) behind the axle.

Personally, I like the sound; not too loud, I can listen to the radio at cruise. But enough rumble to get noticed. Much like the original exhaust sound, just louder and with some more rumble. Some brands of mufflers change the sound. Everything sounds like a rustang or pick up truck with certain brands of mufflers. The Super Turbos don't do that.

The Dynomax Super Turbos are great if you don't like power. They sound good, fairly quiet compared to some other mufflers, but they are very restrictive.

My car is street hemi with approx 11.2 to one compression. A VERY mild flat tappet cam in the 500 lift range ( dont have cam car handy ) But it can idle just under 1000 with no problem or noticeable lope

Stock H pipe in ft and stock tailpipes out back

My car
https://www.youtube.com/watch?v=qz5UFRtnWWw


https://www.youtube.com/watch?v=0wV1myYnCn8

Im not after every ounce of power. I dont race it and rarely beat on it.

Ive had a lot of people comment its doesn't sound like it should considering its a hemi car

The 383 car I owned. But these were a 2.5inch TTI system

Im more than a little curious how much a change , if any it will be with my hemi car and 2.25 tail pipes

https://www.youtube.com/watch?v=H1eP_QMFfMU


Something tells me if I go with the Ultra Flows and a straight thru design, Im not going to like it, I have a feeling its TOO loud

How about a side by side test?

I also have Doug's electric cut-outs. Have had them for 20 years on both the big wedge and this big Hemi. We have a cool 1/8th mile strip 5 minutes from me that I used to hit regularly. Especially when they had the KOS series going. My car was 2 time class champion. So, I have ran it many times through the full exhaust and with the cut-outs open.

Why don't you guess the actual difference in ETs?

Same here. Ive looked / listened to multiple vidoes of the short case design, and everyone mentions a drone. At which speed seemed to depend on car and exhaust type ( Headers or not ) And THAT is not acceptable for me

Mike, Offset in and center out

No idea on the interior design.

My car has 3.91's and exhaust manifolds , drone was around 30-40mph , right at the speed I mostly drove it. The car is basically going to be a race car so I shouldn't be too bothered by the sound of the ultra flos., but like you on a cruiser I don't want something obnoxious .

I don't think the hemi mufflers have the u bends in them like the super turbo ... I'd love to cut one open ... which I read is based off a design by David Vizard ... Sonic Turbo ... according to Vizard his design didn't cost HP, he has a youtube video about them.

I remember having them on my dads 340 duster with headers back in the early 80's ... this period of my life wrecked my hearing ...

Some years ago, Car Craft (Frieberger?) did a flow test and maybe a dyno test on a bunch of mufflers and the Super Turbo did really well.

https://bangshift.com/forum/forum/bangshift/tech-section/3202-some-muffler-test-info

Somewhere I have the issue with the test in it, but who knows where it is anymore.

Once I change them up. I'l cut one of the repop hemi mufflers open for a look see

Don’t remember. 15-20 years back. I’d have to say they weren’t a super long case.

No need to cut them Bill if they are correct, you should be able to see through the "Hemi" mufflers as they are the same design with the angled, perforated inner pipe as the Dynomax Ultra Flo SS and welded from what I remember? I have a set still in the boxes that I got back in the '90's that I might be able to get to, but do I want to open the unopened boxes ? Someone here has to know if they are the same design as the Ultra Flo's ?

hi

i am going to change my pypes brand street muffler to their race muffler , quieter than their street muffler !

look it up !

511 cu hemi

I never had a set of them , that is very interesting .

Accurate has sound clips mufflers

Super Turbo with a center exit. The exhaust has to flow around the exit pipe. Not my picture. This topic has come up before and I saved the picture.

I'm running those mufflers on my Challenger.

TTI 3" exhaust, 402ci Magnum, 9.8:1CR

https://youtu.be/7KEn2UltCJc

I've used 17748, the 2.5" version on my 2005 5.7 Hemi Magnum.

*It's important to differentiate between the short case one that usually drones, and the long 20" case model that usually doesn't.

The car had no cats and an H pipe, so very similar to an older car in that regard.

I loved them, they were just right for a good, throaty sounding driver that was never annoying.
Long distance drives, 3-5 hours, no problem at all.

They do not flow well. The car felt faster with 2 chamber flowmasters, and even those don't flow well.

But they do keep the car pretty quiet and sounding good.

I feel they are a little too quiet for an occasional short distance Hellraiser kind of a car which is why they make the race bullets and the ultra flo.

That was my line of thinking , I was going to try to fit the 20" case muffler in place of the short case to see if it was the case.

Only time I've experienced drone in my cars was:
1. 3" system with Flowmaster 40s with before-axle turndowns - 2.5" tailpipes cured it.
2. '64 Savoy wagon 3" system with almost anything - tried 3 different sets of mufflers to get the right sound - and tailpipes cured that.
Both had quite "healthy" RBs that seemed to merit big pipe.
I think the interior volume on the wagon - basically a big drum - was a large part f the problem.

As for case length, it seems to me that the more volume in the case, the less restrictive it is.
But I have no date to prove/disprove that.

I have this video,
1967 GTX , basically stock 440

It has just a tad more rumble than my car presently does. I think I like it


https://youtu.be/lnO333xn7zY

Just took this.
I just put a fresh set of plugs in. So ignore the smoke

https://youtu.be/7PfxZ13QXPE?feature=shared

Well, I used to work for Dynomax & I can assure you, a 2.5" version of the Super Turbo flows better than a 2.5" or 3" 2 chamber, 3 chamber, or Delta flow Flowmaster. The 3" Flowmaster versions had flow rates of around 350 scfm, while the 2.5" Dynomax Super Turbos have flow rates of around 410-420 scfm. Comparative OE mufflers have flow rates of usually under 200 scfm. I remember buying a pair of 16" bodied Chrysler "Hemi" mufflers from Mitchell Motors back in the early 80's - to replace the 20" bodied originals on my old '71 Hemi Charger. The mufflers from Mitchell flowed like CRAP - I could immediately tell they were restrictive. Back then I didn't know crap about exhaust. I should have installed a set of Walker Red Line Z mufflers, which evolved into the Super Turbos.

The big differences internally between a Dynomax Super Turbo & an OE muffler are two things: the size of the internal perf tubes, & the Super Turbos have flow directors (bank turns) at each end, & OE's do not, and most other performance mufflers won't either. If you buy a 2.5" in/out Super Turbo, it will have 2.5" flow tubes inside. An OE type muffler with 2.5" inlet/outlet, will usually have 2" dia internals. A CHEAP, crappy turbo muffler (like the Thrush California Boss Turbos) have 2 flow tubes internally & NO packing, plus the flow tubes are smaller diameter. Super Turbos have a fiberglass mat that wraps around the center section of the muffler (you can see it in the photo someone posted), but this mat breaks down in about a year or two, & the mufflers will get louder - especially the 14" ones. Some oval mufflers have two flow tubes, some have 3. The Super Turbos are GOOD turbo mufflers. The Dynomax Ultra-Flow mufflers are straight-through, & they do not "tune" the sound like Super Turbos do, so they sound different than each other. From a flow standpoint, the scfm of a 2.5" 14/20" Super Turbo offset/center is around 410, and a straight-through Ultra Flow is around 1100. There is a HUGE difference in flow, but do you really need the extra flow of the Ultra Flow? Only a few dyno runs could tell you. Bob Karakashian & many of the other guys running in the Pure Stock Drags are using the Dynomax Ultra Flows. Those WAAAAAY outflow flowmasters & all other non straight-through oval mufflers. The stainless Ultra Flows with the stock-style spun-locked heads, flow the same as the Dynomax race series welded construction mufflers - also now called Ultra Flows. The welded series are offered in bigger flowpath & bigger in/out than the stainless ones, so there is more variety. On a closing note, I don't know what the internals are like in the Accurate mufflers, & I don't know who is building them for them - I doubt they have the equipment to build them & especially fab the spun-locked heads. If they do, then that's impressive.

There are quite a few mufflers currently in the Dynomax & Thrush line that I suggested & partially designed. There were also ones that I tried to get them to bring to market, but was unsuccessful. One was reverse flow Super Turbos in 2.25" & 2.5" versions for AAR's & T/A's - the standard oval size but 20" long. *They currently offer these reverse flow mufflers, but they are only 14" long bodies - not long enough. Those were referred to as "fabricator" mufflers. I have been building my own chambered exhaust mufflers & mufflers for AC Cobras since 2002.

Do the 6" round ultra flow sound or perform different than the more conventional oval shaped ultra flows? They might fit on each side of an ebody gas tank.

Found a pic of what I am considering.

A good pair of headphones is the best way to listen to this Dynomax "Sound of Dynomax" link

https://www.dynomax.com/sounds-of-dynomax/?muffler=ultra-flo-ss-polished-muffler

SOUND OF DYNOMAX LINK CLICK

Mike, Listening to them . along with the 67 GTX video I posted earlier today. Im no closer to picking a muffler than ever.

Bill, honestly I think you would like the Ultra Flo's SS or welded. Nice muscle car throaty sound at idle, quiet and no resonance or buzzy sound at cruising speeds and then a great sound during acceleration or kickdown or down shift acceleration. I forgot that I do have a brand-new set of Ultra Flo SS also still in the boxes that I bought to replace those Flowmaster 40's currently still on the GTX.

Is it possible to pair a resonator with the super turbos that will tame it down, kill the drone and maybe some overall sound, without knee capping performance?

I have some stupid thrush ones that my exhaust guy is fairly sure are flowmaster knock offs. I don’t like these and one is starting to do the popcorn thing from internal rust. I’d love to add an h or x pipe, new mufflers, and add factory exhaust tips behind my stock 440. I had been leaning towards getting the accurate stuff, maybe the hemi ones, and some sort of resonator, their stock ones or otherwise.

I just don’t know.

As I mentioned earlier, putting any cheap glass packs (now they're called bullets) in the tail pipes behind the axle will pretty much kill the drone. And they won't 'kill' the flow.

Everything I've found says the 17747 Dynomax is a 2.25 tube muffler. Is this truly what you are after because most replies in this thread are speaking to 2.5 or 3 inch diameters?

Some things people in here have stated and I think most of us would agree to - 2.5 and 3 inch tailpipes will increase the sound. Straighter thru mufflers will increase the sound. Higher compression ratios will increase the sound. More cubic inches will increase the sound.

Since your engine is built, you can't alter the displacement or comp ratio. That leaves exhaust system as the only mods. A change to 3" tail pipes could give you the extra sound you want. If you don't want to change your pipes, then put a more straight through or free flowing muffler on it. Super Turbo and Ultra flow both achieve that. IMO ,the reproduction system was designed to match factory specs which wanted to meet a certain NVH requirement that the factory set at the time. Anything that flows better will be louder, only question is how much so. Despite what the sound clips are putting out there, I'd venture the extra turns inside a Super Turbo will be quieter than the straight through Ultra Flow. If you are afraid of it being too quiet, you can go Ultra Flow. If its too loud, then add resonators.

These places both have big block sound clips on similar cars that might be more accurate than the Dynomax site and might be able to help you find what you want:
https://www.gardnerexhaust.com/sound-clips/
https://www.accurateltd.com/B-Body-Mufflers-_p_192.html

Correct the 2.25 is what I need / want. My exhaust is in excellent shape so In not changing pipes . I just want a little more rumble.

Ive looked at the Accurate hemi HP mufflers and their standard hemi mufflers . But at almost $500 for a pair.
Im looking for less expensive alternatives

Keeping it 100% OE stock appearing isnt top of my priority list

Like I mentioned earlier.

This is my 383 car and has the Dynomax Super Turbos only in a 2.5inch version and If I thought my hemi car would be similar to or maybe even a tad quieter. I would pull the trigger on the 2.25inch version and move forward

https://www.youtube.com/watch?v=H1eP_QMFfMU

Whats interesting is this 67 440 powered GTX and my 66 383 powered Satellite have the exact same exhaust system on them . 2.5inch TTI and Dynomax 17748 mufflers all thru the OE stock exhaust manifolds on both car
The only difference is the tips. And to my ear they have a huge difference in sound

https://youtu.be/lnO333xn7zY

Is that GTX even running? IMO, there is too big a difference in recording quality to even consider that a valid comparison. No way they should be that different.

IMO, Super Turbo it. $110 for a pair. You already have experience with those and are happy with them on the Satellite. At 2.25, I'd guess they may be just a skosh more quiet. If your unhappy with the sound on the Hemi, then Ultra Flow it at $170 a pair. Heck, buy both and your still only 50% of the Accurate system mufflers. Sell off whichever pair you don't want and recoup 90 percent of your money back. You then will have a side by side comparison you can use to come back here and use to convince someone to buy what you don't want.

"Im no closer to picking a muffler than ever"


ahh, just leave 'em off............

That's quite a difference between the two: I like the yellow car much better. It has a crisp sound to it, whereas the GTX sounds like a 318 car.
Maybe '66-'67 cars are different from '68-'70, but IIRC the later 440 cars had an H and larger pipe before the mufflers.
Plus, the manifolds on the RBs should be further apart due to deck height, no ?

FWIW, my yellow car sounds pretty much like your yellow car - and it isn't because of paint - but my blue car sounds pretty much like the GTX.

Both cars are equipped with a full 2.5inch TTI system , both are H pipe equipped
The 440 GTX is box stock.
the 383 Satellite had a small cam, approx 10-1 comp. and stealth aluminum heads

Nope - they are straight-through just like the oval versions. These are great mufflers, but they just sound "flat" to me - they do NO tuning. They are more like resonators.

Here's the chart for the Super Turbos. All of the single in/out Super Turbos will flow in either direction, but for an A-Body or B-Body you will enter next to the driveshaft on the offset, & come out for the tailpipe center.

Here's a pair of my chambered mufflers on a 68 B-Fish w/340: https://youtu.be/PdW5Vy1Dtv4 (I think it's one of our Moparts members' cars)

I wonder what the difference is between 17767 and 17747 . appears to be the exact same specs


Edit, per Summit. the 17767 is not avail


Either way, I have a set of the 17747 in the wifes Amazon cart for her next order . So they should be here in the next week max

A bit late to this party, but my Charger has a 440, tti headers, 2.5 pipes into Super Turbos. Nice rumble but not obnoxious.

I have the 17733 on the Dart and 17748 that I got from TTi when I bought the system for my Bee .I just realized the 747 is 2.25 tail , 748 is 2.5.

I wonder if Dynomax changed the design because the charts says 410cm flow but the box , I still have them with 3" borola xr1's in them , says 376cfm ?

This is exactly why I find it hard to pick mufflers. You hear a much different sound on two cars that should be pretty close.

One thing I’ve wondered about is if the Accurate (or other) repops would flow like factory? Reading old road tests I have, a 68 GTX 440 with ac could punch just under a 14 second ticket at the strip. I’m sure that was a worked over car they gave the press, but did they swap mufflers on such? If a true factory muffler can flow like that, it should be all I need for a stock 440 car, if repops are spot on that is.

My two cents on the subject of Dynomax mufflers is that over 20 years go I went with the longest “RV” stainless steel straight through Dynomax in the 2.5 inch diameter. Its price was lower than the heavier advertised performance SS Dynomax models, I suspect because RV owners pay more attention to value. As a single muffler it had a low deep tone with very little high frequency noise and cut backpressure to half that of the Walker Quietflow square case before it. I then bought the shortest stainless steel RV Dynomax as a “resonator exhaust pipe end” The resonator addition dropped the 1600 to 2000 rpm part throttle highway cruise sound level.

Mistakes I suspect I made back then:

I did not know how to “guest-i-mate” the effective length of exhaust pipe from main muffler to resonator to “fine tune” frequency range of noise.
I was not aware of what “T Stub pipes” could accomplish noise & frequency wise.
I did not have, or attempt to borrow, a dB meter with frequency range adjustment. (free Apps for that today)
I did not understand the pros & cons of changing the EGR tap point from exhaust manifold to way back somewhere behind cat con and/or muffler(s).

The stainless steel exterior of both main muffler and resonator still look great after all these years.

Interesting how they define sound profile by "street" or "sport". I'd assume the street nomenclature to mean somewhat quieter that a sport call out. Would have been nice to a certain engine combo test notation with resulting decibel levels at idle and cruise.

I'm looking at this picture and I can't fathom how this is not a pretty restrictive design with that exit pipe blocking the flow. The next set of mufflers I get will be the ultra flows.

I've used a race bullet as a resonator on a 4" system on my 24v valve Cummins ram , doesn't really do a lot to quiet it down.

I'll take your word for it as an expert, my experience is based on seat of the pants only and I didn't do any testing.

Sometimes a louder exhaust feels faster so maybe that was the effect I was experiencing.

Sometimes the desire is only a targeted change or improvement and the dynomax got me there.

The car was totaled not long afterwards so that ended pretty abruptly.

Bill,
I have the mufflers you are asking about on my 68 Hemi Road Runner. The 2.5" in/out Dynomax's. You are welcome to come up to the Phoenix area and we can go for a ride if you want??
Chris

Thanks, I ordered a set this morning. So, they will probably be on the car before the Phoenix show next month

Chris the 2.5 in out is the 17748 , Bill was asking about the 17747 with is 2.5 in , 2,.25 out.

John,
747 is 2.25 in and out
and should be here by the end of the week

Years ago I had a set of the early Thrush 2.5 inch inlet and outlet turbo muffs on my 1969 Dart GTS with a set of Hooker BB 2.0 inch fenderwell headers feeding into the muffs under the middle of the car with a set of 2.5 inch tailpipes exiting in front of the rear tires. I was testing tire pressure on a new set of M/T 28x10.5x15 slicks at the old LACR 1/4 mile strip, it rana best of 12.23 at 109.+ MPH with the exhaust on the car, I removed it the next morning and it ran 11:39 at 117.6 MPH with no other changes, the D.A. was within 500 FT, it was lower, of the previous evening
I later did a similar test with a set of the early Magnaflow crimp muffs that had a 3.0 inch in side inlet with a center outlet , those muffs where 14 inch long ovals with 7.0 inch tall. They were on my last pump gas street and strip Duster with the same headers that were on my 1969 Dart GTS it ran a best of 7.01 ET at 93.4 MPH in the 1/8 mile at Madras, OR with the complete system on, those muffs were mounted behind the rear end and the rear bumper. I remove the complete system and that car ran6.96 at 93.8 MPH best the next day, probably due to the less weight
My message is some muffs hurt performance and some don't, bigger diameter pipes are better

There is a drastic difference in performance b/t the Ultra Flow and the Super Turbo. My dad's road runner...fairly mild 440 six pack, worked 906 heads, 509 cam, headers and full 3" exhaust.
We switched from Ultraflows to Super Turbos and it felt like the car lost 40 hp. It was bad enough that my 70 year old dad came back after the first test drive and said we had to change it back! He liked the sound (he wanted it quieter), but the loss of performance ruined it.
We decided on a set of Hooker Aerochamber mufflers. Not as loud as the Ultraflows, but louder than the ST's, and the performance felt a LOT better.
These were all 3" offset in/center out.

oh thats even worse , I thought I read it was 2.5 in ... need to get my glasses updated

its what the pipes on my car are. Im after a sound, Not all out performance

Maybe someday down the line I would like to up the full exhaust to a 2.5inch system front to rear . But thats a project for another time