[82ltdqs]

Anybody running these 16inch body 17629 units?

I purchased them because they are a super turbo with an added Helmholtz chamber to reduce drown, but they seem very restrictive. I’m thinking of switching to the long body 17749’s but I’m worried they won’t fit. The transitional 14 inch 17734 units seem like they will fit the best, but I’m worried about them being too loud. Any advice or experiences?

Do you guys know if Tom Hand is still around? I was hoping he would chime in.

Thank you

[ZeGermanHam]

I just installed the Dynomax 17629 mufflers on my '66 this weekend. I bought them because people seem to like the mild nature of the SuperTurbos, which is what I'm after. That said, I actually wanted to use (and bought) the Summit Racing knockoff turbo muffler (p/n 631225), because unlike the Dynomax mufflers, the Summits stay a full 2.5" and don't neck down to 2-1/4" internally like the Dynomax mufflers do. Frankly, the Summit mufflers are better constructed, less expensive, and are made in the United States. I am not particularly impressed with the build quality of the Dynomax mufflers, particularly the inlets & outlets.

Alas, the Summit 631225 mufflers are 1.5" wider and didn't fit my car due to my UMI chassis bracing, so I ended up using the Dynomax mufflers after all.

If you're curious, here is a video showing what the Dynomax 17629 mufflers sound like on my mild 400ci with Doug's long-tube headers and 2.5" exhaust tubing with H-pipe: LINK

Helps if you wear headphones while listening to the video. Like most other mufflers, I imagine they will sound a little different after they've been used for a while and broken in.

[82ltdqs]

Wow, I can’t believe you responded.

I saw where you responded to a YouTube video mentioning that you had these mufflers and were going to put them on your GTO, but I did not know how to contact you.

So I knew I wanted a Dynomax brand super turbo, and I wanted to use the 20” inch long body 17749 units but they seemed too long. The 14 inch 17734 units seemed just right but I feared would be too loud. I found these 16 inch 17629 units and bought them. Only to learn later that they are not exactly turbo mufflers. I mean a half is and the other half is a hel lots chamber. Dynomax says they only flow 350 cfm. I’m so bummed. Check out the photo I added of the internals of the muffler. They do have an S flow but there is not much room and no flow directors.

Did you notice a decrease in performance?

Also, not sure how to add a photo

[82ltdqs]

So for some reason, this forum does not make it easy to add pictures and still operated in the dark ages and asks for aURL.

Click this link and look at the reviews. A picture of the of a diagram of the internals is posted in the reviews.

https://www.amazon.com/Dynomax-17629...pe=all_reviews

[ZeGermanHam]

I can't speak to any changes in performance, since my car is not roadworthy yet.

As far as photos go, you need to add them as an attachment. If using a regular web browser and not a smartphone, click the "go advanced" button when typing a reply, then click the paperclip button to attach your photo.

[82ltdqs]

Here it is

[82ltdqs]

Thanks man. I was able to make it work. As you can see in the pic, the right side is the turbo side and the left is the Helmholtz chamber side. Problem is that the area on the far right where the exhaust turns back around and where a flow director should be, is too small. I measured this with a tape measure and small extendable mirror. It’s only about an inch deep. It’s super small. They sound great on my car, but I really feel they will be restrictive at high RPM’s.

[82ltdqs]

See how small the space is? Of all the turbo mufflers offered by dynomax, this is the oddball.

[ZeGermanHam]

Although I understand the fundamental difference between this model of the SuperTurbo and the other models, is the 1-inch distance between the end of the tubing and the walls actually any different? How close do the tubes get to the walls inside the other SuperTurbos?

[82ltdqs]

Look at the cutaway of this general turbo muffler. There is a lot of space at both ends.

If you look at the second picture of the used 17629 unit and pay attention to the pinch welds, you can see that one side of the turbo section (the middle) the other side are different sized. Look how the heat build up changed the colors of the metal. The right side seems to really restrict flow. I think that’s why the color changed so much. So much heat that it hammered the metal. Which I believe these are stainless steel.

[82ltdqs]

Man your car sounds great with those mufflers! I would really like to make these 17629’s work. Are you running an aftermarket cam?

[ZeGermanHam]

Thanks. It has a stock cam in it right now.

[AG]

I've used the 17734 mufflers on an A-body and they were not too loud.

[82ltdqs]

What about with a big cam? Even these 17629 units are on the edge of too loud for my set up.

[The Champ]

Assuming these are going on your '65 Catalina. Please correct me if I'm wrong...

Not sure why you'd have fears that the 17749 wouldn't fit on a full size car. I've got them on my '64 GTO Convertible and no issues with fitment.

Very happy with the 17749's. I wanted some sound, but with a convertible I didn't want excessive sound. Absolutely no drone whatsoever.

[82ltdqs]

Nice! Thank you

[AG]

Originally Posted by 82ltdqs

What about with a big cam? Even these 17629 units are on the edge of too loud for my set up.

I was using a RAIV cam in a 400 so it was relatively healthy. That of course is subjective.

[62posbonny]

I know of a 64 catalina running a 455 041 combo with headers, 3" to the mufflers with H-pipe, 17749's and 2.5" tailpipes and it's quiet. I'm talking pedal to the floor and inside the car you only get a throaty low tone that defies what you are experiencing quiet.