1125 Custom Exhaust Project

[Hellgate]

As you know I've got the "ugly" bike, a Buell 1125R. It's odd so I kinda like it. What I can't stand about it is the OEM muffler. It's what's called an Hemholds muffler and from an engineering prespective it's pretty ingenious. On the downside it's fugly and weights 19.9 lbs.

View attachment 25389

The other problem with this muffler is the fact that an O2 probe can't be incerted deep enough to get a clean 4 Gas reading while on the dyno. (That was a bit rude wasn't it?)

So the next muffler was the Jardine. The only reason I bought it was because it was inexpensive and we could get a clean/accurate reading with it. It does look much better but it was too loud and the tone was terrible, sounded like a 143hp lawnmower. The other problem is it didn't make power and lost power in the mid range.

View attachment 25390

Then I thought I found the Holy Grail, the Free Spirits RS413 full system. Looks great, sounded pretty nice (but not great), and fitment was ok, not great. It make good power with the baffles in the mufflers, but not great. So we pulled the baffles and we made killer power! But...it is at about 110 db. Way to loud.

View attachment 25391

View attachment 25392

So after consulting with the Master himself at AF1 Racing, Micah, I plunged into the next exhaust phase; creating longer runners and much greater muffler volume.

So I bought a used Akrapovic full exhaust system for an Aprilia RSV1000.

View attachment 25393

View attachment 25394

The plan was to use a local muffler shop, Muffin, to remove the back half of the Free Spirits exhaust, mount the Akra cans, one on each side, and build "runner" from just past the X pipe to each muffler. Muffin declined the job and recommended Pipeworx. Welcome to Pipeworx

Matt the owner of Pipeworx suggested we completely remove the exhaust from the X pipe back and build new and tighter runners to the mufflers. Matt had me buy "exhaust donuts", stainless steel circles, and stainless steel J pipes.

View attachment 25395

View attachment 25396

The end look will be something like this, but the cans I have are 350mm, the ones in the photo are 450mm.

View attachment 25397


Soooo, that is what I need the DB Killers for.

 

[Motogiro]

Very cool project. And by the way I think the the 1125 is one of the coolest looking machine out there!

 

[DefyInertia]

You're crazy! Can't wait to see the vid clip once you're done. In person would be even better :thumbup:

 

[Motogiro]

You're crazy! Can't wait to see the vid clip once you're done. In person would be even better :thumbup:

Yeah every time Wavex pulls up to me it's like the hammers of Thor! Haha!

 

[dako81]

Can't wait to see what you make of this. I currently have an r1 muffler setup sitting at home waiting to be mocked up. I want the true dual cans persona with an arguably milder tone and prescence for more noise comfort when on the long haul. A quality fabrication company who can do good work with some stainless tubing would be good to know about, even if they are a long distance from me.

 

[Hellgate]

You're crazy! Can't wait to see the vid clip once you're done. In person would be even better :thumbup:

I agree, after this winter I'm ready for some SoCal weather.

 

[Hellgate]

Can't wait to see what you make of this. I currently have an r1 muffler setup sitting at home waiting to be mocked up. I want the true dual cans persona with an arguably milder tone and prescence for more noise comfort when on the long haul. A quality fabrication company who can do good work with some stainless tubing would be good to know about, even if they are a long distance from me.

It is hard to find a good muffler shop. Matt at Pipeworx was the welding/exhaust guy at Revera Course while they were open. He's really picky about his work and a perfectionist. So many times muffler guys are the complete opposite.

When I walked in his shop he had a Duc 1098 on Pit Bulls and he was measuring for a complete custom exhaust for the bike. I knew I was in the right place.

When he builds he doesn't bend any exhaust pipes, they are all cut using the donuts, the J bends, and then welded. There is only one supplier for donuts and very few pipe builders are aware of them. I am SO lucky I stumbled onto him. Very nice guy too.

I'm hoping he can get to mine project next week. He had a '55 Chevy and a '32 Ford he needed to get out of the shop first.

 

[Drinky]

im not realy into the pipe welding thing, but whats a donut for?

 

[Hellgate]

Good question.

Donuts are sliced, like a piece of pie to change the direction of the pipe without bending it. Unless a shop can hydroform a pipe, it is very difficult to maintain the same inside diameter of the pipe as it is bent. Typically a muffler shop pipe will have a "kink" on the inside bend of the pipe. The problem with this approach is inside diameter is now smaller than the rest of the pipe and causes a restiction. The leading exhaust MFGs use donuts to make their products, especially headers; Akrapovic, Leo Vince, etc.

Here's an example of how a donut is sliced and rewelded into a shape.

View attachment 25401

Here's an example of a kink in a pipe (right pipe), albeit this one looks pretty good, but for tight bends that are required for a motorcycle it wouldn't work too well.

I tired to find other examples but no luck.

View attachment 25402

 

[Hellgate]

I dropped the bike and materials off yesterday at Pipeworx, and paid my deposit. Now it is like waiting for Christmas! I hope by mid next week the system will be complete.

 

[Motogiro]

Cool! Can't wait to see this!
Just put a set of TBR slip-ons on the new steed but your project requires much more hands on engineering and knowledge on your part.