My take on a true undertail exhaust for my f3. I spent way too many hours online looking at only a few people who have attempted some version of an undertail exhaust, but nothing that I totally like. I debated routing the exhaust through the swingarm, doing a dual exhaust etc...anyway, I figured what the hell, so I decided to try and emulate a 600rr swingarm and exhaust setup.


https://cbrforum.com/forum/album.php?albumid=2552

I only have a couple pictures so far. I have the swingarm pretty well laid out. I cut the right side out, pushed it in towards the suspension mounts and then used some sheet metal to fab the rest. The picture I attached is just with everything roughly mounted and tacked. I have cut the exhaust and am getting it set up right at the moment.

As for the actual muffler/silencer, I wanted to model it after a ducati exhaust. I have tried all kinds of ideas with cardboard templates but nothing that I really like. I bought a ducati 999 exhaust which I will try and configure into the bike. At this point I am just looking to have the swingarm and headers in place, welded and looking good. Will post new pictures asap.

 

let us know how it came out.. i love the idea of under tail. i might make that mine next winter project.

 

Got it all welded up and fitted! Came out pretty good when welded. I went back later using my ****ty stick welder and filled in some of the low spots and surface imperfections. I did the best I could but had to resort to a filler for the final stage. I contemplated body filler but many claim it will break down under heat, JB weld was the best suggestion as it has a high temperature resistance. I header is welded up as well, but in the process of cleaning it up. Pictures of that will be posted soon!

Lastly, while I spend a lot of time reading on this forum, I don't spend a lot of time posting. I have sorta figured out how to post pictures, but only thumbnails. How can I post pictures so they show up within the text body??

 

looking sweet man!

 

Got a few more pictures of the swingarm. Did one coat of primer to see how it looks in a uniform color. I need to do a little more hand sanding here and there, but pretty pleased with the result. I also attached a few pictures of the headers welded up. Similar fashion to the 600RR.

I will have to try and find some paint that is a close match to the stock swingarm color. I want to keep it looking like everything is stock. I can possibly get it powdercoated for cheap, but will have to look into colors.

Haven't moved to the exhaust yet, I am going to clean up the welds, smooth everything out, test fit again and then paint with a flat black heat resistant paint. The hardest part will be snaking the remaining exhaust under the tail of the bike. There is enough room, just the bends and angles will be tough seeing as I lack the proper equipment to do a proper job.

I am a little ocd about how the muffler will be mounted. As previously stated, I bought a ducati 999 muffler. I love the look but it is a massive piece that will require lots of fab to get right. The thing also must weigh in excess of 20lbs! I had an idea to fabricate a piece that mirrors and takes the place of the tail light. I can then mount all the lights and plate underneath. Seems like a lot of work though. I had also debated hiding the muffler all together underneath the seat, similar to those hot body kits for the 600rr's.

 

Some pictures of everything mounted up. I will need to tweak the headers slightly to fit into the swingarm pocket a little better then finish weld and clean up. I plan on running the bike with the tire hugger on as shown in the pictures. This will require removing a bit of plastic where the exhaust will go. I am going to order some 2" 45 and 90 degree mandrel bent pipe to fab up the midpipe. After completing that, I am going to have it ceramic coated inside and out. This will seriously reduce the exhaust pipe temperature so all plastic pieces in the area should be safe. I was thinking about making a heat shield, but I think the ceramic should do a good job.

 

lookin good!!

 

for protection of the plastic you could wrap the exhaust too?

 

Thanks. Always an option. Ill start with the ceramic and if that doesn't perform to my liking I will wrap it all up.

 

looks awesome.

keep posting....