Cat Box Opened Up

OK, you guys wanted to know what is on the inside of our cat boxes. Time to find out.

I had a few moments this morning and I thought what the hell, let's just see. So I took the cat box off my '07 figuring this would be easy and after I took the guts out I'd just stick it back together and take a ride.

So you start with the kitty on the bench. First thing is take the heat shield off. The construction is such that you can't just cut the thing in half, because innards are on a frame that is spot welded around the box. You have to decide which half you want to take off and then grind down the spot welds after you cut the shell in half. I used cutting disks on my grinder. Took about an hour and a half to get it apart.

From what I see, there really is no "Baffling" to speak of. The exhaust goes into the chamber through the magic metal tube and then just goes out to the three exhaust ports. I think I will remove the magic metal tube and stick it back together. OOPS, I can't stick it back together, I think it is stainless and I can't weld stainless, I don't have a MIG welder. Guess I should have thought of that first? Who is going to volunteer to stick it back to gether for me if I pay postage both ways. Surely this educational post is worth that!

This modified CAT box will only be used for off road competition. I have a new one on order for street use.


I think I still have mine all intact if you need one. It's off an 05 and do not think it's a cat but just a bafflle resonator.
 
Also have the original pipes that I drilled out through the baffle plates to get a much better sound. I hate to take them to the dump. They need a good home.
 
So the only difference for an N cat is the magic metal tube is empty? Huh, no wonder the thing weighs a ton empty or full. If you need practice I have 2 full ones in my shed collecting bugs.



The mention of 'cat' weight--- I've removed mine this last w/end, awaiting the by-pass pipe, I popped it on the scales for curiosity, the cat weighed 12lb--fair ol' lump of unwanted metal doncha think ?.
 
I need to ask, ( even what I consider to be ), a "dumb" question, but I want to understand, and I don't want to guess. The cat box bypass pipe allows you to take the cat box off the Rocket, and save it for temporary reinstallation, in the event a future emissions test is required, ..... but in the meantime, you ride using the cat box bypass pipe, and experience the benefits it has to offer? Is that right? I clicked the Ebay link, and looked at the photos. Are the other pipes on either side of the bypass pipe blocked, or just bypassed, so they're not part of the equation? I have two exhaust mufflers at the rear of my 2013Tourer
 
Accidentally posted too soon. Wasn't finished yet. Asking, what splits my exhaust into my two rear mufflers, after coming through the cat box bypass pipe? My 2013 Tourer has two mufflers in the back. One on each side, under the hard bags. Also, wanted to ask, will using the cat box bypass pipe give me a louder, richer exhaust note? I guess a retune will be required too? Right? Thanks... Russell
 
The cat boxes in the R3T are in the silencers. A set of TORs or other after-market pipes will eliminate the cats.
 
The cat boxes in the R3T are in the silencers. A set of TORs or other after-market pipes will eliminate the cats.
Thank you. I didn't know that. I've looked under there, and didn't really see a box structure for exhaust collection, and redistribution, but I figured I was overlooking it. Thank you so much.... That's great news. So, only the Roadsters have them? That means Touring models would never need a bypass pipe kit? Perfect. One advantage of having a Tourer.
 
Cat Box Opened Up
I recently removed mine and installed a cat box delete which i ordered from a guy on eBay and had to come from Great Britain, i would have mailed my cat box to you had i known you would still want to put that thing back on, but i couldn't wait to get rid of it and **** canned it in the dumpster, bad timing i guess!
OK, you guys wanted to know what is on the inside of our cat boxes. Time to find out.

I had a few moments this morning and I thought what the hell, let's just see. So I took the cat box off my '07 figuring this would be easy and after I took the guts out I'd just stick it back together and take a ride.

So you start with the kitty on the bench. First thing is take the heat shield off. The construction is such that you can't just cut the thing in half, because innards are on a frame that is spot welded around the box. You have to decide which half you want to take off and then grind down the spot welds after you cut the shell in half. I used cutting disks on my grinder. Took about an hour and a half to get it apart.

From what I see, there really is no "Baffling" to speak of. The exhaust goes into the chamber through the magic metal tube and then just goes out to the three exhaust ports. I think I will remove the magic metal tube and stick it back together. OOPS, I can't stick it back together, I think it is stainless and I can't weld stainless, I don't have a MIG welder. Guess I should have thought of that first? Who is going to volunteer to stick it back to gether for me if I pay postage both ways. Surely this educational post is worth that!

This modified CAT box will only be used for off road competition. I have a new one on order for street use.
 
Also have the original pipes that I drilled out through the baffle plates to get a much better sound. I hate to take them to the dump. They need a good home.
I had to take my tors off and put stock pipes back on to quiet her up a little as I do run a decat crossover pipe and that was injuring my ears, but you say you drilled out through baffle plates and got a much better sound. Louder or better ? And how did you drill? Any pictures?thanks
 
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