Has anyone compaired the 2 types of Mousse can muffler designs?

One is by the Spad webpage:

http://www.spadtothebone.com/SPAD/Mufflers/

The other design is at the following:

http://webpages.charter.net/rcfu/ConstGuide/MCM.html

The Spad design states a 2000 plus rpm gain and the other 800 plus rpm gain.

They both seem to be easy design but differ in the construction designs.

Anyone dare tell us which is better?????

Larry

There's no way you're going to gain 2,000 RPMs over a good muffler just by fitting a mousse-can.

Even a good tuned pipe will struggle to provide a 2,000 RPM gain on most engines and a MCP doesn't come close to offering the RPM hike that a proper pipe does.

Typically you can expect 800-900 RPMs with a good MCP (in my experience).

Just compaired the Mousse can to stock mufflers. I was very suprised with the results.

Magnum .15 xls, 7 x 8 APC prop.
Stock muffler - 15,700 rpm
Mousse can - 17,010 rpm
Gain 1,310 rpm

Magnum .25 xls, 9 x 5 Master Airscrew prop.
Stock muffler - 15,500 rpm
Mousse can - 16,800 rpm
Gain 1,100 rpm

Both construction of the cans were identical with the exception of the Macs header.

Did try tuning the can up and down the length of the header and really found no noticable increase or decrease in rpm.

Below are some pictures of the .15 muffler.

I am going to make one for my Evolution .46 and see if it will wake up my Raptor f-22.

After spending hours trying to tune a expansion chamber for a .46, this simple add on is easy and cheap. Going to sell my tuned pipes.

Larry

By the way, I didn't make the assumtion of 2,000 RPM gain I quote from the internet:

" Using the Mousse Can Muffler

A much stronger, better running engine and a beautifully functioning and long lasting mini pipe can be expected. An 800-RPM increase is normal while a 2200-RPM increase is not unreasonable. The engine idle will be better and throttle response will be smoother. These pipes usually work best with engine/prop combinations that run in the 13500 to 16000 RPM range. A typical power gain for a Thunder Tiger GP25 or GP40 is about 40%. An engine should sound better and will most likely be quieter than if a stock muffler were used. All this comes from an assembly that weighs only 2 ounces "

In my case I got half that but I am happy.

larry

Larry,

Is your moussecan hollow (connected to the MACS header) or is there a pipe inside the can?

Terry in LP

Header is inserted about 3/4 - 1 inch into the can. The inside of the can is hollow.

Larry

Thanks, Larry. Have you tuned the stinger or header length?

Back in the early '90s Webra introduced a pipe, with their .61 LS engine, that was very similar in design to the moussecan/canister type of exhausts in use these days. It had a 'trumpet' shaped entry to a high volume constant diameter expansion chamber/can and claimed a broad rpm band boost. I am familiar with the tuned muffler types (1/4 wave pipes?) and have used Magic Mufflers in the past. These moussecans seem to be the poorboy's versions. I've gathered some materials for making a few examples and have been trying to find some specific info on before and after rpm numbers and appreciate this thread.

Terry in LP

Well for what it is worth, the pics show the pipe I made for .15 and .25 engines.

I did try the muffler on a .46 macs header and on my evolution .46 engine. As posted, the stinger was only .25" x 4". I lost RPM.

Today I was looking for some 5/16 aluminum pipe but all hobby store in the area didn't carry it.

I did try a stock header and Moouse can with out the stinger. RPM still was low on the .46.

Tomorrow I will get some stinger material and give it a go again.

Are you making a pipe for a .61???

If so I don't know how much info I could supply as I am a small engine guy.

Now with that said I am selling 3 Macs tuned pipes and one of them is for your size engine.... Might look on ebay

http://cgi.ebay.com/ws/eBayISAPI.dll...:L:LCA:US:1123

Larry

My plan is to make .40/.45, .61, .90, and 1.2 size moussecan muffs of adequate to excessive volume for each different displacement. Already have some tuned pipes and tuned mufflers/Magic Mufflers/Irvine Super Silencers to compare to.

The .40/.60 MVVS and Irvine SS have fixed/short approx. 1" stingers and the .40/.60 Magic Muffs have stingers that are adjustable to about 2.5". The Jett tuned muffs have short, small ID stingers. All with roughly 5/16" ID.

Terry in LP

Made up 2 versions of my mousse can muffler for my Evolution .46.

Did some RPM measurements and came up with this comparision.

Ver #1:

macs header, 4oz mouse can, 4" 5/16 stinger

Stock setup 12,500 RPM w/10 x 6 APC prop.

Ver #1, Max PRM 13,100, w/10 x 6 APC prop.


Ver #2:

Stock muffler header, White rain Moouse can , 4", 5/16 stinger,

Stock setup, 12,5000 RPM, 10 x 6 APC prop.

Ver#2, Max RPM 14,200, 10 x 6 APC prop.

The results show the winner.

I did not try to TUNE the stinger, maybe I could tweak a few more RPM or Loose some. I was happy with the results.

Version #2 is a .46 stock header, the Mousse can fitted to the end of it, NO baffle inside. A 6/32 threaded rod to hold it all together and a 5/16 x 4" stinger on the bottom.

I tried this version without the stinger and got very poor results, no back pressure in the can and it was just noisey.


Larry

Larry,

Great info!

"I was happy with the results." I would be too!

Have you tried a longer header on #1? What method did you use to attach the stinger to #1?

Terry in LP

The only Macs header I had for a .40 size engine was 5 inches long. I had about 2 inches into the can.

JB weld epoxy holds the stinger in place. I tried using Aluminum solder but my first try melted the stinger. So I just epoxy'd it in.

I also didn't mention that the larger White rain muffler only weighs 1 oz more than the stock muffler.

larry

Many of us flying RC Combat have spent a lot of time with these mousse cans. It really depends on the engine, of course. But if you set it up right, you can get a tuning effect. The most noticeable effect I've personally seen is on the Webra .25, using a macs header and can combination. The can is slide most of the way onto the header, with some silicon holding the can in place. You can slide the can up and down the pipe a bit in the field. And when you hit the sweet spot you can hear the engine take off and the RPM just jump right up, and if you get it in the air, you can sometimes see the plane accelerate.

When on the pipe, I've tached just over 21k on a MAS 9x4. With the same fuel, same pipe, but at the wrong length, it often drops to the low-mid 18k range.

If you're putting the can at the end of the un-cut header, you're setup is probably too long. It's a quarter wave pipe, and that means it's going to be a lot shorter than a typical tuned pipe.

btw, the Webra .25 has very aggressive porting. It gets a huge boost, but it dogs badly if things are not set right. The OS .25FX, on the other hand, shows a solid RPM increase on the can, but nothing like the Webra. The OS is also not as sensitive to the can length though, so it's easier to get a solid setup that runs well, even if you aren't screaming like the Webra.

also, hitting 21k+ rpm on a MAS 9x4 is just nuts. The prop starts flexing and the blades just start tracking all over the place. Looks like it'll toss a blade or something if that kind of sillyness is maintained. I usually run an APC 9x3 Combat or a russian carbon 9x4 APC clone on the hot webras. These props are stronger and stiffer, but don't rev quite as high.

I've never tried a can on anything bigger than a .25/.28 class combat engine.

This is my first experience with the cans. I have tried tuned pipes before but it was flustrating to get it tuned just right.

Since i had some macs headers sitting around I thought I wold try the Moouse can muffler. Googled it found some websites. Hat trick gave me the website for the 4 oz cans that I used on the .15 and .25 magnums. Like i stated above i was suprised how easy it was to tune and the immediate increase in PRM's.

I'm sure that I could tune it some more but I dont fly combat and havent flown the cans yet due to snow and wet weather. Was hoping to do that today but got rained and snowed out.

What I really wanted was to pep up my Hangar 9, raptor with the evlo .46. That thing bearly stays in the air with the stock set up. The muffler I made for it did give me a boost in RPM, so Im really looking forward to trying it out.

Larry