KRX with DIY SuperTrapp

5115 Views 26 Replies 5 Participants Last post by MOKRX, Nov 11, 2020

MOKRX

Discussion Starter · Oct 18, 2020

Hey Guy's,
Just wanted to show you my exhaust project. It's a SuperTrapp 443-2217. 4" OD/2.25" ID. I made a dxf file for the flange and cut it at work. When I first put it on I was conservative and only used 4 disc. Wouldn't hardly get out of it's own way. Went to all 12 disc and it feels about like the stock muffler powerwise but louder. Took all baffles out so it was just open and it rips good but really loud. Noticeably more power than stock. For those (and I didn't) that don't understand SuperTrapp mufflers, the more disc' you add the more flow and sound you get. Ordering more today. Still working on a hanger as-well.

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Rocky Heap

· #2 · Oct 18, 2020

good work

Speedyg

· #3 · Oct 19, 2020

MOKRX said:
Hey Guy's,
Just wanted to show you my exhaust project. It's a SuperTrapp 443-2217. 4" OD/2.25" ID. I made a dxf file for the flange and cut it at work. When I first put it on I was conservative and only used 4 disc. Wouldn't hardly get out of it's own way. Went to all 12 disc and it feels about like the stock muffler powerwise but louder. Took all baffles out so it was just open and it rips good but really loud. Noticeably more power than stock. For those (and I didn't) that don't understand SuperTrapp mufflers, the more disc' you add the more flow and sound you get. Ordering more today. Still working on a hanger as-well.

Question do these have a catalytic built in? Reason I ask is I can’t stand the smell of exhaust. Main reason I still have stock muffler. No smell.

MOKRX

Discussion Starter · #4 · Oct 19, 2020

No cat.

Sandman_73

· #5 · Oct 20, 2020

How would you fit a cat in there??? Its just a motorcycle can. Dont think I’ve seen a Supertrapp since 1980.

Speedyg

· #6 · Oct 20, 2020

Sandman_73 said:
How would you fit a cat in there??? Its just a motorcycle can. Dont think I’ve seen a Supertrapp since 1980.

There’s compact mufflers out there that have a cat built in. I prefer a cat on my machines.

Sandman_73

· #7 · Oct 20, 2020

Speedyg said:
There’s compact mufflers out there that have a cat built in. I prefer a cat on my machines.

Good luck with that. Bout the only thing you'll find out there with a CAT is OEM. Only thing they are good for is generating ridiculous amounts of unwanted heat.

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Speedyg

· #8 · Oct 20, 2020

Sandman_73 said:
Good luck with that. Bout the only thing you'll find out there with a CAT is OEM. Only thing they are good for is generating ridiculous amounts of unwanted heat.

Doesn’t bug me at all. I prefer the stock muffler to be honest. This is riding in the desert at 110 degrees. If there is another option I’m sure it will come to light eventually. Plus where there is forests round her mufflers and spark arresters are strictly enforced. Not sure I have much of a choice.

Sandman_73

· #9 · Oct 21, 2020

A CAT is NOT a spark arrestor or muffler. Do you know the difference? The rangers dont give a crap about a CAT

MOKRX

Discussion Starter · #10 · Oct 21, 2020

Actually the Supertrapp with the end cap like I put on is a US forestry approved spark arrestor.

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Speedyg

· #11 · Oct 21, 2020

Sandman_73 said:
A CAT is NOT a spark arrestor or muffler. Do you know the difference? The rangers dont give a crap about a CAT

Didn’t say it was. Of course I do. A spark arrester keeps from flames or sparks coming out the tailpipe potentially causing a fire while riding. A catalytic converters reduces harmful gases and pollutants. Exhaust smells give me an instant headache, that’s why it’s important to me.

Speedyg

· #12 · Oct 21, 2020

MOKRX said:
Actually the Supertrapp with the end cap like I put on is a US forestry approved spark arrestor.

Yes the times I’ve been pulled over out here they look at the muffler for a stamp. I’m sure if they were really bad A holes they would ask for documents with an aftermarket exhaust that’s forestry approved.

MOKRX

Discussion Starter · #13 · Oct 21, 2020

Speedyg said:
Yes the times I’ve been pulled over out here they look at the muffler for a stamp. I’m sure if they were really bad A holes they would ask for documents with an aftermarket exhaust that’s forestry approved.

Probably so. If you look close at the first pic you can see it stamped on the cover. Guess this one is legal.

MOKRX

Discussion Starter · #14 · Oct 25, 2020

Good morning,

Well the SuperTrapp was too loud for me. I like the look and light weight but it yells a little to much for us. So, I bought a 2.5" in/out DynoMax turbo. (17615) At idle it's just a few dcb's louder than stock. Stock muffler weighs 25.5 and this one weighs just over 8. I made a dxf file for the flange if anyone wants it. I just made one "S" looking steel bar for a bracket and used the bottom. It's hardly seen. I'd like to sell the Supertrapp if anyone is interested and it is spark arrestor approved. SuperTrapp 443-2217 4 inch Universal S/C Elite Muffler 17in/2.25in ID - Brushed S/S If I was going to keep the Supertrapp, I would add a few more disc for more flow. The machine was noticeably stronger with the pipe just open without disc. SuperTrapp says 22-24 disc is about the same as running it open. I'd suggest 16-18. Has 12 now. You can buy 6 disc for about $35 when I checked. I'd take $180 for it and you pay shipping.

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MOKRX

Discussion Starter · #15 · Oct 25, 2020

I also want to add, I ran the new dynomax yesterday and it topped out at 67 and 68 downhill. About the same as stock, however, I did notice the temp hovered around 160 or a little over. Pretty cool here right now so I'm sure that has something to do with it but still notable.

Thumper13

· #16 · Oct 25, 2020

Interesting, so the more discs, the louder, right? At some point, I want quieter than stock.

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Sandman_73

· #17 · Oct 25, 2020

Have said it before... Guys trying to put a SINGLE tiny 250cc dirt bike can on a 1000cc monster is just a bad idea. Lound, raspy, poor flow... Why would you do that?

That Dynomax is much more suited for this motor. Take the Supercrap and toss it in the trash.

MOKRX

Discussion Starter · #18 · Oct 25, 2020

Sandman.... that tiny supercrap dirt bike can has enough flow to support 200 hp. I've got 6 inline 4 muscle bikes in my garage, 2 of which have way more hp than this little 1000cc twin and have more restrictive exhaust than that SuperTrapp. It's 2.25" straight through. Plenty of flow for this 112hp machine, it's just a little loud to suit me.

MOKRX

Discussion Starter · #19 · Oct 25, 2020

With regard to power with the Dynomax Turbo muffler. A friend of mine has a KRX identical to ours except his is bone factory stock. Mine has the primary clutch spring removed and the DynoMax muffler.
We raced 5 or 6 times and mine would pull away everytime. The race was on grass and the length was about 250'. We even switched and he thought mine was a little peppier. My engine temp is a little cooler than his as well which I expected. Probably do a computer tune next to compliment the free flow exhaust. Like I said earlier, if anyone wants to make their own exhaust similar to what I did, I have a file for the flange if you want to have a machine shop cut it.

Rocky Heap

· #20 · Oct 25, 2020

I've had very good luck with supertrapps in the past, it's the tunability that makes them ideal for some situations. Any of the other "megaphone" mufflers like Trinity are just a straight through non baffled pipe...........and way too loud.

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