I'm preparing to fully core my S2R800 stock mufflers and shorten them by about an inch. I got the perf tubes and glass matting from LA Choppers. Wear eye protection. Basically you need a Dremel with pencil attachment and some small heavy-duty abrasive disks. Use the smaller disks(non-reinforced because the reinforced ones are too big so use caution)to get inside the end of the can and cut the attachment straps. Then pull off the endcap. You need to slip the aluminum sleeves off the muffler to reveal the steel inner muffler. Next you use a chop saw to chop them just above where the attachment plate mounts on both cans. They will be different. On the top can you may wish to leave the heat shield mount attached by a strip of steel which means more work, and you will want to use the fiber-reinforced disks for this. Next you will need to do some more Dremeling with the small disks to cut the inner pipe down as close as you can to where it enters the muffler. I say as close as possible because that will be the point at which it is most centered in the muffler. Measure the perf tubing, and make little slots in the end and bend them out slightly so that the tube will fit over the end of the inner pipe snugly(I'm using 1-3/4"). You don't need to use anything to hold it there, but I plan on using some hi-temp JB Weld or similar. Wrap the perf tube with as much packing as you can. Again, the end of the tube must be slotted so you can bend the tangs out to fit over the inner ends of the endcap tips. Fit the outer sleeves back on, and reinstall endcaps, with hi-temp sealant at both ends of the sleeve. I use copper Permatex RTV for this purpose. I will rivet the sleeves to the muffler at both ends, but perhaps you can get away with only riveting the endcaps since the sleeves will be held securely by the muffler attachment plate bolts. I use aluminum rivets - some say use SS but they are harder to deal with if you want to take the can apart again for any reason. The aluminum rivets won't 'melt' or what have you as others have suggested. Stainless rivets are overkill for this exercise. I also fill in the centers of the rivets with epoxy putty and Dremel them down as flat as possible to decrease their visual presence. To polish it all off I then mask off the steel inlets and outlets of the muffler, rub them with some steel wool, wipe them down with isopropyl alcohol and spray them with Rust-Oleum Hi-Temp BBQ grill paint. Voila you got what is essentially a Termi can for much less cost and factory appearance. Although I haven't gotten off my ass to do this yet, I have planned it for months and have all the materials. I first partially cored them, and found that although the sound of partially cored stock cans is awesome, they don't really breathe like the Termis, they're still too heavy, and so I will fully core them as I really don't like the look of the Termi cans I have on the bike right now. Be advised you can perhaps get away without having to adjust fueling if you only core the cans and leave it at that. If you chop the airbox or use a DP airbox or pod filters and/or go with a cat-eliminating midpipe you need a DP ECU or PCIII or similar and a fueling adjustment. Since I plan to chop the tail when I finally get off my ass(too busy riding) I am going to chop the mufflers down by a tiny bit. I have Ducati by Termignoni stock cans, and 1" is as much as I can chop them without cutting the D off of the Ducati logo stamped into the aluminum.
DUDE! Very sweet, thanks for the breakdown!!
Now all I need to do is to do it. Can't wait to get started. Now where do I get the perf tubing? Besides getting it online. Maybe the Home Depot?
