Modifying Stock cans

[rideserotta]

I exchanged email with a fellow DMFer who had bought his M620 with his exhaust shortened and cored. Apparently it sounds and looks great. Anyone done this themselves or had it done? What's involved and what type of shop would need to do it? Any idea how much that would cost?

[muskrat]

I did it and wont do it again.  You better have a dremmel in hand and lots of cutting wheels to remove the welds.  To me that was the worst part.  They do sound and look much better of course but it's quite a bit of work.  If you have $400 you can buy slip-ons and be done quickly 

[chris1044]

I chopped/cored my stockers on my M1000...they not only look great now, but they sound great as well.

I used a whole saw to cut the inner portion of the outlet, then a chop saw to cut them in half.  They're packed inside with some packing now...all in all, if you're handy I'd say it's worth a day/weekend to do this. Will try and get some pics/links to an article I used when I get home tonite...

[rideserotta]

Chris... I'd love to see a tutorial if you have it.

muskrat... what slip ons would you recommend?

[He Man]

I did it and wont do it again.  You better have a dremmel in hand and lots of cutting wheels to remove the welds.  To me that was the worst part.  They do sound and look much better of course but it's quite a bit of work.  If you have $400 you can buy slip-ons and be done quickly 

Thats casue you did it the hardway. Chop saw + air grinder @100psi = 2 minutes to open that sucker up.

[booger]

Cored two pairs and it was totally worthwhile and easy. Dunno what Muskrat was referring to but the Dremel is the perfect tool for this.

And I did two pairs of S2R cans. They're more difficult.

All you need is a Dremel with a supply of heavy-duty reinforced cutoff wheels, some fiberglass exhaust packing mat, some perforated steel muffler tube, hi-temp RTV, a cheap rivet gun with 1/8" aluminum rivets, and a free Saturday.

Follow this guys' instructions to get the muffler outlets off: http://www.ducatisuite.com/mufflers.html

And read and adapt my instructions in the Tutorials section on removing the rest of the guts/fitting perforated tube and glass packing: http://www.ducatimonsterforum.org/index.php?topic=35964.0

You should be able to read and combine both sets of how-tos to arrive at a fully cored setup for your Monster. Don't do it however if you are just going to half-core it and not pack it. That's ghetto and doesn't sound as good.

Prep well and use some hi-heat primer and paint available at any McParts store, and badabing. Not hard at all and beats the hell out of paying $400 for slipons.

[jc.cyberdemon]

my bike came with chopped and cored exhaust, chopped very short they are about 10-12 inches long.im getting rid of them for real cheap send me a pm.(they are off a 620 with lowmounts).

[sejman]

The low mounts are easy...chop saw (I used mitre saw with 10" abrasive blade) to chop 3" off each right through everything. Then slip sleeve off cut end and cut welds to remove stainless end caps. A dremel is a pain so get yourself a pack of 3" abrasive cutting wheels and arbor for a regular 3/8" electric drill...much better.  The trick is not cutting the welds themselves but through the sheet metal of the flange on the end cap - much easier. Clean up the cuts on the now shorter cans, slip the end caps on, slide sleeves over, drill some holes and pop rivet the whole assembly together. Whole process takes about 2-3 hours...most for first can then second goes quick.

[jc.cyberdemon]

sent you pics on the bike....

[chris1044]

Cored two pairs and it was totally worthwhile and easy. Dunno what Muskrat was referring to but the Dremel is the perfect tool for this.

And I did two pairs of S2R cans. They're more difficult.

All you need is a Dremel with a supply of heavy-duty reinforced cutoff wheels, some fiberglass exhaust packing mat, some perforated steel muffler tube, hi-temp RTV, a cheap rivet gun with 1/8" aluminum rivets, and a free Saturday.

Follow this guys' instructions to get the muffler outlets off: http://www.ducatisuite.com/mufflers.html

And read and adapt my instructions in the Tutorials section on removing the rest of the guts/fitting perforated tube and glass packing: http://www.ducatimonsterforum.org/index.php?topic=35964.0

You should be able to read and combine both sets of how-tos to arrive at a fully cored setup for your Monster. Don't do it however if you are just going to half-core it and not pack it. That's ghetto and doesn't sound as good.

Prep well and use some hi-heat primer and paint available at any McParts store, and badabing. Not hard at all and beats the hell out of paying $400 for slipons.

X2..the link posted to the S2R can's here is what I based mine off of - mine are the low mount variation.  They ended up being roughly 10" long, so the entire second/last chamber is gone.  They're loud, but harley's without baffles are louder. 

I got rid of the steel inner portion all together, so mine are made up of the inlet exhaust tube/flange section riveted to the outer aluminum beauty cover, perforated tube wrapped with some quality packing, and the end cap riveted on.  I had to take a dremmel tool and cut the triangle/chamfered section at the bottom of the aluminum outer piece off, which allowed me to get the sleeve entirely off of the mufflers.  I the inner steel muffler down to roughly 1" over-all length.  Slid the aluminum portion back over it, welded the piece I cut off them back on, and used nuts/bolts to secure the mounting tabs back to it.  Next I took the perforated tubing I got, cut it to length, wrapped it in packing (more the better...), inserted it into the aluminum sleeve and rivited the end-cap on. 

Voila - roughly 90% lighter than stock can's, totally serviceable, and they sound great.  Took about 50 bucks in cash with the packing....as he said above, beets the hell out of some 400 dollar slip-ons that really aren't any better in flow than what I've done (flowed on a bench when done.....cylinder head ports will restrict flow before these do, at least based off calculations as I haven't flowed a cylinder head).

[rideserotta]

Thanks. I'm considering JC's but am wondering if having them that short will affect or harm the engine. Another thread talked about the shorter cans causing too much engine heat. Any thoughts on that?

[jc.cyberdemon]

im a nice guy... i dont think they will hurt anything. have em gratis! just pay for shipping and there yours..

[rideserotta]

Wow! That's awesome. Let me know your paypal and much. I'll add some for gas and your time.

[jc.cyberdemon]

yup thats what we do around here.....