Side Pipe Mufflers
 

Ok guys, I have been working on a design of an interchangeable floating core perforated side pipe muffler. I have discussed the design with a manufacture/ fabricator who likes the idea. What do u guys think?

What I have come up with is a stainless outer shell with a machine fit at the collector. It looks just like a normal muffler (coned up on the front, and the rear), however; it can be disassembled in a matter of minutes, and the core changed out to a smaller or larger core. I have seen other modular designs but no interchangeable core. If anyone is aware of an in changeable core please let me know. also I am familiar with V Band clamps, but I do not care for the look.

The Idea has been on my mind for a while. I live in a neighborhood that does not share my interest for the sophisticated sound a big horsepower V8 engine makes. On days when I will be coming in and out of the neighborhood I can use my 2” core and on other days I can use my 3” core to take full advantage of my engine.

Not a new Idea a good one but not new. We did our first set almost 20 years ago. I could not get any one to buy them in the kit market. Cost was the mane factor. I have a new side pipe with a removable muffler tube and have been installing them. At about the rate of eight sets a year. WE have all so figured a way to keep the external timp down to 178 degrees with an internal timp of 575. Our next trick is to pass the sound check at Laguna with 1300 HP If you can figure that one out keeping the side pipes. I would like to here about it. so far we have come up with capping the out lets and running 3" tubing to a large can in the trunk and putting six oval holes in the deck lid .

Thanks Bill, i was quite sure someone had come up with idea before me. I have no interest in finically gain just want to contribute to our hobby.

My design starting from the collector and working toward the muffler is as follows.

Front muffler cone is welded to the collector, a machined fit ring will fit over the collector and under the front edge of cone to maintain uniform roundness and for self alignment. The aluminum ring will have a machined fit to the collector and will be attached via stainless pan head screws from inside the collector. The machined ring will be tapped vertically and horizontally. The perfrated core will have a slip fit over the collector and a welded flange ring on the front. The perforated core flange will attach to the larger ring via pan head screws. The perforated core will be wrapped in ceramic mat and will allow the rear of the core to float. The muffler housing will slide over the Matting and over the machined aluminum ring (the ring will create a very snug fit). muffler housing will attach via pan head screws to the machined ring(there s a self alignment dowel on the bottom of housing (out of sight) so that when muffler housing is tapped into place perfect alignment is achieved).

To replace core do the following:
1. Remove muffler housing screws and pull housing off
2. Remove core screws and remove core
3. Slip core new over collector and screw on new core (core is already wrapped in matt).
4. Align housing and tap into place, attach screws.


I have left out some other details, however; the general design concept is conveyed. The design is for natural aspirated engines.

If i made a few mistakes in grammer or syntext do not flame me. I am in bed with the Flu.:CRY:

I am in bed with the Flu.
Me To that's why I am on here.lol It sounds good to me. The aluminum bits may not hold up it will take the right aluminum. also you may find that screws and bolts do not work well in a exhaust system on a cobra. Some kind of locking system should be used on the screws and bolts.

Aluminum Bits? i think your fever is higher then mine. :LOL:

Do u think the aluminum 6061 ring would see temps in excess of 450 degrees since it is shielded from exhaust gasess (I do not want the weight of a stainless ring)? I do agree with u on the screws. Do u think a stainless locking washer with Ultra copper on the screws would keep them tight? I could always counterbore the top holes and use a bolt and nut but it adds to machining.

Thanks for you input!

Mark

dissimilar metals and torque load vibration Time and heat cycles. All bad things for aluminum. Of coarse I am seeing little wind up cobras with bunny ears right now. err what a minute those could be my girl friends slippers. May be one of the real engineers on this site could chime in on this. sprinting for the

Aluminum 7068 is the latest alloy making its' way into DoD/Aerospace applications. Combines the strength of steel with the weight of Alu and is used where high strength is required along with good resistance to corrosion and temp cycling fatigue, you might want to look at that. Can be ordered in tubes, bars and rounds of all sizes.

... and not that new, but the qualification programs for aerospace are extreme and take years to complete when fully characterizing end-of-life failure modes.

Thanks for input. 7068 sounds like the best choice, if available ( cost :eek:) , if not maybe 7075. My neighbor is an aerospace engineer, so i will pick his brain on monday.

Thanks again for the help

I used Howell Racing mufflers as they make a great performance muflfer that is 4 inch round outside and 3 1/2 inches inside and the right length for a Cobra. Now if you like them a bit louder like me, turn them around backwards. Running a all aluminum 496 FE 681HP and it sounds and runs great........:)

Thanks for your input Gary, but what i am looking for is dual purpose muffler. The engine should dyno over 700hp now , so i need at least a 3" perforated core on track days and play days. Driving around neighborhood i need to lower the decibels.

If your neighbor says yeah we use it, the next question you should ask is "can I get a peek at the scrap?" You would be suprised at what these companies throw away :JEKYLHYDE

Talk about getting rid of stuff you guys should visit a Boeing surplus store! Braided stainless hoses by the pound, instruments, tools, etc for bargain prices. They are located in Renton Washington and Topeka Kansas. Tom

where are they at in topeka, i might take a look?

Guys I googled it because I hadn't been there in years. The Kent Washington store is closed. They have one in Wichita Kansas. I don't know if it is still open. The address is:
Boeing Surplus
401 W. 47th St.
Wichita Ks.
316-526-7415
Tom

I don't know if it matters to you but going with 2 (or more) sets of mufflers may be quite a bit easier. I built a set for my car (BDR) using V band clamps at the collector. Using these I can remove or install my side pipes literally in 3 minutes because I only have one bolt to loosen/ tighten. I think I understand your end goal of being able to switch your sound out-put quickly and I believe your current plan will work. It just seems to me that it'd be a lot easier just to swap pipes on out cars. Works well on mine and if you have the fab skills to do what you're talking about then this would be child's play. JMHO

http://i266.photobucket.com/albums/i...ehamr/EX21.jpg

http://i266.photobucket.com/albums/i...ehamr/EX17.jpg

http://i266.photobucket.com/albums/i...ehamr/EX20.jpg

Before.
Before - YouTube

After.
After.3gp - YouTube

Steve a v band would be faster and more practical, however; I prefer not to use the v band if I can make the modular muffler work (no disrespect to your setup). I will vacillate on this for a while.

No problem man, just throwing it out there.

You should consider the temperatures the Al will see. If 6061 T6 does get over 350 F then it will reduce it strength. Look at the capabilities of the new 7068 and it seems to state a time (100 hrs is not much) over 250 F will reduce its strength.

http://www.kaiseraluminum.com/wp-con...8-brochure.pdf

I work with 6061 and its cast equal C355 and we limit the temps to 350 F and even then it will only be for short time, i.e. 10 % of total life of 20 years.

Also the thermal expansion differences make a difference too and can impart HUGE stresses if not considered.

Steel is about .06 and alum is about .1 for a relative comparison.

Lee

There are or were some FLOWMASTER muffler that were not 304 Stainless on this site's classifieds. Nobody in this are does ceramic coating. Jay Leno has these same mufflers on a 427 FE SOHC except his are stainless. 3.5" inlet and outlet.

I guess if they sold, you will know if you contact seller on this website. Seller is jpetran. Jay Leno's car is not excessively loud and has built in heat shields, too.

I am aiting for new sidepipes with three-bolt flanges in front of 3" straight through mufflers with heat shields that came with car.

BE HEALTHY SOON.