The $15.00 custom exhaust

Ladies and Gentlemen,
I’m a complete amateur but I made a custom shorty exhaust that sounds awesome, doesn’t bug the neighbors, and only cost $15.

The opportunity came when I had to create a license plate mount that works with the FSD undertail. I needed new tires and couldn’t go to the shop without a license plate so the tools came out. I’ll put pics of the mount and paint job in another post. I decided to gut my cans so off came the exhaust. I had cash in hand from my tax returns for Laser Extremes so I felt brave enough to do some experimenting.

I cut the end cap off one of the cans and spent a good 45 minutes trying to get the guts out. I drilled and sawed and eventually realized I’d have to split the can in half the long way or cut the other end off or spend the rest of the evening drilling. I also realized that I wouldn’t be able to weld all this back together in a satisfactory manner because I have a crappy welder and I make crappy welds.
I decided to try some experimenting before ordering the Lasers. Here’s the plan; Use baffles by themselves or with steel wool and put them in either the “up pipe” from the cat or have a one-up 2” exhaust bent up under the seat and put the baffles in there.

Parts: 12” by 2” baffle from J&P Cyles = $10 + tax + shipping
$1.00 steel wool
Tail pipe expander = $15, but it broke so I’m returning it so really it’s free

Results: I ended up with an awesome sounding 10” baffle in the up-pipe wrapped in steel wool. For the first time my bike sounds like a freaking throaty V8 and it’s not loud at all. AT ALL. I’m actually going to pull some of the steel wool out because it’s too quiet. It’s about 0.5 decibels louder than drilled cans, but with way more bass. I have definitely lost some mid range torque so I’m going to spend the money to have a custom map made for my PC-III (I’ll experiment with some downloaded ones first). I expect it to get louder as the steel wool ‘beds down’ or possibly blows or burns out. I have lost a massive amount of weight. The new pipe weighs about 2 pounds and the stockers are super heavy, so you do the math. (Super heavy - 2lbs = lots lighter). My rear end feels almost weightless.

Inside stockers. I drilled three holes then gave up.



Stock cans with ‘up-pipe’ cut off. I’m going to keep calling this an up-pipe.



The up pipe is not round. Tail pipe expander ($15) from Harbor Freight will fix that. Also it’s ~48cm and my baffles are 2” so it needs to be expanded anyway.



Tried a few positions to see how I liked them. Up is the only way to go. Sideways like this would burn the passenger. I also tried with and without the heat shield. Don’t want to clutter this place up with pics though. This pic has my favorite shop helper.



Baffles from J&P Cyles. 12”x2”, 4”x2”, and 4”x1.75”. Needed a few to experiment with. The 1.75” is too small. The 4”x2” wrapped in steel wool is the freaking sweetest thing I’ve ever heard. EVER. Possibly a little too loud so I’m not rolling with it. In contrast, it is not nearly as loud as the Harley I had with straight pipes or as loud as the CBR600 I had which had blown out it’s fiber glass. I’m not trying to wake the dead here, but I do like it louder than stock.



I had to expand the pipe a little. Broke the expander. I break pretty much everything from Harbor Freight. The lesson here is to always make sure the expander is all the way in the pipe.



Ground down the expanded bits of the baffles so they’d go in. You want them to fit nice and snug.



Tap tap tap that puppy in there.



Steel wool goes on. 4” without wool is as loud as my Harley was.



4” w/ wool is the awesome-est sound in the freaking world!! Possibly too loud though. Not as loud as some other bikes I’ve had though. It’s deep and throaty. I can’t explain how good this sounds. 12” has to go in. It’s too long. I cut it and wrapped it.



4” next to cut 12”



You have to wrap the wool really tight. You’d be surprised how much you can wrap on there. Smoosh it down as you go. It’ll hold its smooshed shape. It’ll also smoosh upwards as you slide the baffle in.



Slid it in. Hammered a little. Put a few tack welds on there.

This is what it looks like from the bottom. You can see the cut-off end of the baffle is jammed right up against the bend that’s near the cat. Large chunks of wool aren’t getting by, but small particles may. I’m hoping the cat catches them and they burn up. I’m really not expecting wool to get in the engine.







Possible issues:
Heat. Only an issue when stopped. As long as I’m moving it’s a non-issue. I’ve put high temp paint in the heat shield. We’ll see what happens in the summer in Vegas.
Breathing exhaust. Only an issue when not moving. I have noticed the smell a bit at stop lights. We’ll see if I end up woozy.

Both of these issues can be fixed by having a 2” pipe bent up under the seat. I can use the same hanger bracket from the stock pipes and do a one up next to the license plate. We’ll see though. I’ll roll like this for awhile.

Let me know what you think. Anyone in the Vegas area is welcome to come by for a listen.

 

So your exhaust is pretty much aimed straight up at your butt?

That may sound really cool - but why?

 

Well the cagers always say, "Why don't you take your loud pipes and stick them up your..."

Seriously though, I had to work with how the stock pipe is bent. The other configurations are right where my passenger would put her leg down. And I like her legs the way they are. She shouldn’t be putting her leg down on that side, but people forget and I don’t want anyone burned.

I may end up getting something custom bent from the cat up. I was thinking of going 2”, stainless steel, single-up under the seat, with an ‘elf ear’ or slash cut tip. But I’m open to suggestions. Of course that’s slightly heavier and more expensive.

 

Pretty interesting set up. How does it sound compared to the gutted exhaust? I'm guess that what you had? If the shorty is what you like, then awsome. I still prefer the look of the stock undertail, with gutted cans. Good luck, good work on the fabriction.

 

I went out at lunch to show the guys and now I can't tell if it's louder than the drilled cans or not. Most of the comments were, "Wow, it's quiet. Throaty, but quiet."

We collectively came up with some design ideas so there'll be additions soon. I'll get it bent out so it doesn't have to point straight up. Then I'll add a bit more pipe so it doesn't melt anything. I'm going to try to make a heat shield for it. Something perforated. I also have to take some of the steel wool out and possibly cut the baffle shorter. Instead of tacking it in I'll use a sheet metal screw to hold it in while I get the sound tuned.

So, this is a proof of concept prototype. It'll get better.

 

I can't really make out what the finished product looks like. Can you post some more pics of the result?

 

This should show it better. It's before the heat shield went back on.

I'm going back to the drawing board though. Even with the underseat heat shield everyting gets too hot. I thought I'd loose heat on the freeway but apparently there's a bubble of still air under the seat while I ride.

Soooo - The exit hole has to go somewhere other than under the rear end. I don't want to go sideways so I'll do a one up and hang it next to the license plate where the left stocker hung. I'll mock up the shape I want and have a muffler shop mandrel bend it for me. It won't be as light or as small as I wanted, but it's still lighter and I'll be able to tune the sound with different baffles.

I wouldn't mind replacing the cat with a straight pipe and baffling it, but I don't know where the heat would go. I guess I'll check out how Buell does it.

 

Pretty wild!

Post a sound clip if possible

BZ

 

You could put one of these or something like it on the end of the pipe to help direct the exhaust output:


I know the picture shows it as chrome, but you could always paint it...

 

DerStuka! I KNEW there was a reason I was reading this thread...it was one of your great pictures! (...cause I sure am not walking towards my VFR with a lit torch and some steel wool!)

You crack me up...:biggrin:

 

I guess I'm the odd man out here.

I think it looks stupid. Not only that, it will probably end up melting the tail section & asphxiating the rider. The bike simply does not look right with those ghetto tail light & gaping voids left by the stock mufflers. To each their own.

KC-10 FE out...
lane:

 

Good thing you held back KC, this could have got ugly :bolt:

 

I'm taking sensitivity training.:biggrin:

KC-10 FE out...
lane:

 

Props for taking the initative to try something different.

Even if I don't like it, that doesn't matter... all that matters that you like it! To each his own!

Keep up the good work.

~mikeym

 

Personally, I think just about any exhaust mod beats the uGLy and HEavY stock cans . . . .

 

I know I am one of the few but I love the stockers... I will never go aftermarket unless they build the same but lighter.

 

SEE! This is why I LOVE this place! Because we can say what we feel! From cutting away with a torch, to KC's straight-forward response, to Alaskan and JasonSmith's opposing views. We calls em likes we sees em! :clap2: :clap2:

ME? I think the stock cans are absolutely booo-ti-ful! I can look at that sweet rear end all day! Sure, I'd like them to be lighter but I just twist my right wrist a bit more and voila! (Or as Derstuka says: "viola!")

 

Well until somebody somewhere can say with absolute certainty that XYZ makes a can that is lighter, slightly louder and much deeper sounding, I'll have to stick with stock. Excellent effort tho, and if we had Reps to give, you'd be getting 'em.

Cheers

 

I put a Holeshot on mine. It weighs 5.5 lbs versus 11.5 lbs for the stock can.
It has a lower tone than the stock can. I have yet to take it on the road to hear what it sounds like in the upper rev range.