Found a catalytic converter a while ago and thought I`d give it a try to see what it does. It should kill a few db which is what I`m looking for and the idea of a clean Paso appeals to me as well
I`m not concerned about any power loss. A lot of it is just talk and even if it is 1-2hp at the top end who cares. There are some good articles about the effects of catalytic converters.
It`s been a really long time that I was looking for carbon cans for the Paso but finding some was almost impossible at least at a reasonable price. So decided to go another way.
My polished Shark cans from page 2
and what`s left of them now
Found some non legal Shark cans in carbon from a SV1000 w/o header tubes on ebay thinking the sleeves could simply be swapped.
They were a bit longer and had to be shortened with a Dremel and large diamond plated cutting disc.
Taping the cf is recommended to prevent possible fraying and then it`s also hard to draw a cutting line on cf.
It should be unnecessary to mention (but I'm always doing it as I don`t know who`s reading this): wear a good dust mask specially when working with carbon or aluminium. Also simple paper/cotton dust masks should never be worn when working with solvents or when spraypainting something as that`ll make it a lot worse. You don't want a mask to absorb solvents. There are special masks for different kind of jobs.
Also when working with cf and a Dremel remember that carbon is conductive and can short your machine if too much cf dust gets inside of it! (personal experience)
The cf cans were absorbtion silencers
It`s only a perforated tube wrapped with a thin mesh, steel wool and sound dampening material. Then there`s a mat to protect the cf sleeve from the heat. The steel wool saves the dampening material from burning and being blown out the exhaust. Parts of the material were already burnt out. Getting the cf sleeve off was easy.
My legal alu silencers are reflection silencers
They are less noisy but as the exhaust gases are slowed down and remain in the silencer longer they get hotter which is why this type of silencer usually does not have a carbon sleeve.
The internal tube didn`t come out - a decision had to be made
I`m convinced they trained an ape to build these exhausts. The inner end pieces are round metal discs which were bent over the ends and spotwelded.
Also all holes must have been drilled by hand as if you turned or swapped the end pieces the holes wouldn`t line up
It was a bit of a puzzle combining parts from both silencers and finding the position in which most holes would line up
To protect the cf sleeve as well as possible the search for a good damping material began. While there`s a lot on the market most is glassfibre stuff which will burn off or melt at 450-550°C. Silicate fiber mats are good for 1000°C but only used in combination wrapped around "normal" damping material.
I did find Acousta-fil (
http://www.firehalt.com/acoustafil/default.htm). There`s a PTX (max 750°C) and a ZT1 (900°C) which is what I chose. Funny enough it seems to be made in Germany but it can`t be bought anywhere here as it`s only sold to exhaust manufacturers. With a little effort it can be found in France and the UK which is where I got it at last. (By chance the seller was helping a race team in Germany a few days later and shipped it from here)
A review I found in the internet:
https://app.box.com/s/dk30bk3t98gw0mmmjs4mg535bcm1z44wTo protect the cf sleeve better I got a 0,7mm silicate welding blanket which withstands 1200°C. All for a good conscience
Shoving the whole package back in did take a few attempts
The new riveting gun. New for €14 incl. shipping on ebay. The rivets almost cost more.
Of course normal gas tight rivets usually used for motorcycle exhausts are 10-12mm long. With the quality of the internal tube 16mm were required
The original rivets were stainless steel which makes sense as due to vibration alu rivets can loosen but that might take years and drilling out ss rivets is/was a pita.
The important end done (the one with the homologation number)
Continuing with the great build quality. The end caps are a little larger than the sleeves so bulge a bit when riveted on.
which is not a real issue as heat resistant silicone should be used to seal the end pieces anyway.
Short endpiece for low, long endpiece for high exhaust mount. Had to use the longer ones as they were on the carbon sleeves and required no new rivet holes being drilled
but that`s ok as I have high header tubes for a SS/8xx which one day might be adapted...
Finally finished and fully legal. They weigh 3.2kg each. The non legal version with alu sleeve is 2.2kg ea.
G.
