Cats out of the 630.

[XLEnduroMan]

Curioustiy killed the cat. I couldn't resist seeing what was inside my TE 630 exhaust cans. I had to see if it was possible to get the restrictive, heat holding cats out of there. It really wasnt to hard a job on my end. The welding was the key, and I couldn't have done this with out a experienced/talanted local guy and his pointers. I opened up one cans and took it to the shop. He said cut that thing open with a thin cut and remove the junk and he could weld it back up for reassembly, no problem. He pointed out the ss 3/16" rivits would need the proper tool to reinstall. One of the little hand riviters wouldn't work.
The can opened up:

I used a hack saw to cut off the inlet, thin and straight, right along the weld. Had to cut through both the inner and outer pipe. I marked it for reassembly. This is what is inside.


I used a 2 3/4" hole saw and the cat was cut out like butter.





I cleaned up all the burs and shavings. A lot of shavings got down in to the can. I made sure to clean out all the debris with a rubber mallet, air compressor and shop vac.

The twins back from the welder. One had to be rewelded. (Probably from my hack saw cut screwing up the alignment. 1 was not so good.) He has the eye for it and he got it right before I picked them up. They went back together no problem.


The inlet side didn't have any sealer when I opened them but I put them back together with some Permatex as there was some crust in there. I cleaned things up with some steal wool before reassembly with sealer on both ends. These cans have a mechanical baffle
so should never need to be opened back up. I like that!

Spinning the 3/16" drill bit SLOW and pushing hard worked wonders on the rivits! Advice from a airplane mechanic. $20 Harbor Freight rivit gun (item 66422) made quick work of the rivits.

I like the look and sound of the stock cans. Mine are hear` to stay!

 

[Fast1]

Great job and thanks for documenting the entire process. Did you happen to weigh the junk that you removed?

You know I might not be the only one wondering if you would like to make some extra money doing another pair...

 

[Muddy Waters]

Also, just to throw it out there, you can do it the Blazes way and ditch the whole innards to save some more weight
http://www.cafehusky.com/threads/de-catting-a-std-09-610.16972/

 

[XLEnduroMan]

The only thing that I removed was the round section of the cat. It doesn't weigh much at all. I didn't put anything on a scale though. The internals are ss and the can is alumium so they don't weigh to much. I think most of the weight is in the nice removable s/a tip. I do have another 630 to de-cat, but that will be it for me. Getting the pipes opened up and cutting the cat out really was easy. Anybody can do that. The key part is the welding as they need to be aligned right to slip back in to the cans. If you know a good welder go for it.

I saw Blazes work earlier but did not want to remove the stock internal mechanical baffle. Just wanted the cat out. I didn't want packing to deal with either. The pipe he worked on is different as he had to cut off both ends. The 630's have the removable s/a tip. That made keeping the rest of the baffle possible. The internals of the 610/630 pipes look the same otherwise.

 

[RDTCU]

I did the brute force chisel/drill/hammer method, took about 15 min per can. Driilled out the center of the honeycomb and split out the rest with a sharp chisel.

 

[Fast1]

Hope you guys are using respirators when going at those cat cons..

 

[lowpr0fi1e]

Would removng the mechanical baffle with and replacing it with an inner core lined with packing reduce the heat from the exhausts?

 

[RDTCU]

Hope you guys are using respirators when going at those cat cons..

That, and a good side breeze from a shop fan...
I like my lungs

 

[ContraHusky]

OK, cat-removers...how much louder is it than stock? I want the cats out for the heat reduction, but I really don't want it sounding like my obnoxious 525 EXC. And I'd love to not spend upwards of $600 on new slip-ons...

 

[RDTCU]

OK, cat-removers...how much louder is it than stock? I want the cats out for the heat reduction, but I really don't want it sounding like my obnoxious 525 EXC. And I'd love to not spend upwards of $600 on new slip-ons...

Not much. Opening my airbox made a more noticeable difference in volume than gutting the cats

 

[ContraHusky]

Also...why wouldn't Aluminum rivets work? It's not like there is a lot of shear stress on those rivets...it's a static assembly.

 

[ContraHusky]

Not much. Opening my airbox made a more noticeable difference in volume than gutting the cats

Did you chip out the cat by working through the inlet opening, or did you cut and weld as done above?
Thanks!

 

[RDTCU]

Did you chip out the cat by working through the inlet opening, or did you cut and weld as done above?
Thanks!

Large drill and flat chisel, but I just got in my perforated tubing to turn the cans into packed flowthroughs instead. I pulled one of the cans apart and put it back together with aluminum rivets and it's working just fine, but once you cut out the center section of the actual muffler, the rivets will actually be containing any pressure inside the muffler, but Al should still work just fine if you make them flowthroughs...

 

[ContraHusky]

...I just got in my perforated tubing to turn the cans into packed flowthroughs instead. ......

Why do that? And...I guess you'll now have to cut it apart and re-weld?

 

[XLEnduroMan]

My ears only seem to notice a difference with a roll on in the approx. 3,000-4,000 rpm range. It sounds more throaty there but then clears up to normal levels. I did have my air box opened up some before the de-cat and that increased the intake noise. I am happy with the slight increase in intake and exhaust sound, and I still have spark arrestors.

 

[RDTCU]

Why do that? And...I guess you'll now have to cut it apart and re-weld?

Once you remove the center section, the aluminum casing becomes the body and contains the packing

 

[weldpro]

I just did this mod a few days ago myself. The only difference was that I used a plasma cutter instead of a hole saw for the cat. I don't know if you did this or not but I made sure I made three different lines on the can, and the intake portion to be cut off & re-welded. All lines were marked 1,2,3 that way I was assured that they would line up correctly. Anyhow I do not notice any extra noise, and the pipes are most certainly cooler than before! A win-win!!!

 

[Ketek]

Apart from cooler pipes, did you guys notice any performance gains after removing the cats?

 

[Blazes]

OK, cat-removers...how much louder is it than stock? I want the cats out for the heat reduction, but I really don't want it sounding like my obnoxious 525 EXC. And I'd love to not spend upwards of $600 on new slip-ons...

Actually i found that the de catted one's are quiter than my Arrow aftermarket pipe and have abetter sound as well --

 

[RDTCU]

I couldn't stand it anymore, since I had the perforated tubing and packing in-hand...
They can't be much more restrictive than the Arrows, for $50 in materials, but not quite as light.
They're about 1.75 lb lighter per can than stock because the whole center section with the baffles and cat tube are in the garbage can, and the exit is roughly twice the area...
The cans were cool enough to touch for a few seconds after a 30min highway ride home after doing this.

Just a bit louder than stock, more "blatty" at high throttle and high RPM's, but I noticed a definite increase in throttle response, but it was a touch lean. Power-on wheelies in first and second from a roll are almost too easy after bumping the JD settings up a bit to richen it back up.
Now I'm curious to see what it'll do with the TE ECU...

I'll touch up the exit hole a bit with some sanding wheels and brillo pad later, just because I'm picky about my work.