Made my own exhaust baffle

Ever since I bought my bike, it had been loud. I've never owned a baffle- the bike came with an oil filter jammed in the end of the megaphone to quiet it down. This worked to some extent, and I've tried different oil filters, cut them out differently, things like that. I finally decided I should try to make a real baffle with fiberglass packing, so I did that tonight.

I still used old oil filters, because they are going to be thrown away anyway, and just happened to have a few in the trash :lol: I like using them, because after you hammer them into the end of your pipe, you will have a hell of a time getting them out. This is good because you don't have to worry about them flying out, but when you want to remove them its a different story.

Heres what I started with, an AC Delco PF1218(the large one), and an STP equivalent of a PF53. I used a 2 1/4" hole saw to cut a hole on one end of the filter.


After I cut the hole, I cut off the closed end of the filter, like this:


After cutting it down, I needed a 2 1/4" ID pipe to fit it. I checked a few stores around town for a perforated pipe, but had no luck. I originally intended to just drill a bunch of holes in some exhaust pipe, but used the plasma cutter instead to cut one in long slits in the pipe. I wasn't sure if this would work or not, but I thought I would give it a shot.


I then welded the small filter to the end of the pipe.


I stuck it down inside the megaphone to try and figure out how long I needed the pipe to be. Typically after pushing it in by hand, it moves about 1/2" when you hammer it in the rest of the way, so I made a mark about half an inch outside of the end of the megaphone and cut the pipe there.


After cutting the pipe and the larger oil filter.


After welding the larger oil filter to the other end.


I originally planned to weld the inside of the oil filter onto the pipe, so the outside would be neater looking. It didn't occur to me until it came time to weld that I wouldn't be able to reach the inside to weld it, because the outside skirt of the oil filter was too long for there to be any room. I had to weld along the outside, and it wasn't pretty. I used brake cleaner to clean the oil off as best I could, but I had a few problems, and as a result it is not very pretty. I supposed I could go over it again, but I'm not so sure I care enough to.

Apparently house insulation is supposed to work well for baffles, so I first wrapped the pipe with some house insulation, then wrapped a layer of fiberglass mat over that. I was going to tie it together with some wire, but as thick as the stuff was, I just left it untied.


Here is the end result. As I mentioned above, it isn't pretty due to the welds, but I can always make another one or try and go over the old welds if I get concerned with looks. I still haven't painted it either, and if I ever find an old oven, I may powder coat it in hopes of hiding some of the welds. I have a powder coating gun and everything else I need to powder coat, just haven't found an oven yet.




Now for the most important part, the sound. At idle, the bike has a lower tone, and sounds better than the open pipe I am used to. I took it out for a ride, and my dad was standing outside to see how far he could hear me. Normally, you could hear me cruising for miles (literally), and he said he could only hear me about 1/4 of a mile away. I even went wide open throttle about a mile down the road and he said he didn't hear me at all. I rode the bike before and afterwards without a helmet just to hear the difference, and it is much quieter. The real test will be with my helmet on and with no earplugs. I've had to wear earplugs with the helmet on with an open pipe, otherwise I would hear nothing but the engine running at 4k rpms.

I think overall I spent $20 on the hole saw and the pipe. The hole saw was $13 (overpriced I know, but lifetime guaranteed at least), and the pipe was $7. I have enough pipe to make another one if I need to, and everything else I used in making this I already had, so it cost me nothing. I realize its a very redneck way to make a baffle, but hey, you gotta do something redneck when you live in the country :laugh:

That is sweet! Nice work.

That's nice. Roy

Does just friction hold it in place? If it were me, I'd drill and tap a 1/4-20 hole 120 degrees apart with a nice SS button head cap screw.

Sweet! Does it run better or worse with your thing stuck in there?

Nice job Toadson! Now maybe you'll ride through Grafton sometime! I know what uyou mean about riding with an open pipe. Gets obnoxious after a while.
Btw, I saw a post you put on here a while back said you were looking for a small fairing for your bike. I have an old Miers pseudo Z1R type fairing you can have for cheap.
I'll never use it.

riverroad wrote:

Nice job Toadson! Now maybe you'll ride through Grafton sometime! I know what uyou mean about riding with an open pipe. Gets obnoxious after a while.
Btw, I saw a post you put on here a while back said you were looking for a small fairing for your bike. I have an old Miers pseudo Z1R type fairing you can have for cheap.
I'll never use it.

Hey, that would be cool! It would be nice to have something to try and mess with. Sometimes the wind still gets to me, it's always so windy around here on nice days.

Right now I've been having some issues with my bike, so I can't really say whether or not it runs different. I highly doubt it does, since this baffle is pretty much straight through.

I'm planning on putting some sort of set screw in it to hold it in place. Before, I never used anything to hold the oil filters in and they stayed in fine. It's surprising how hard it is to get them out.

Thanks for all the comments! I really wish I had just left this thing tac welded, as it looked much better then. I'm still trying to come up with ideas to make it look better that won't risk making it look any worse, haha. I'd like to find an endcap of some kind, but I dont know what I could use.

Toadson, Ingenious approach, I like it. Your' core might be a little more effective if you increased # of plasma cuts, as this is where sound waves are diffused.(long strand wrapped glass packing ala' dirt bike, would increase life) You could probly reduce the length of rearmost oil filter body by 1/2 and still retain by staggering say 3 pop rivets around circumference.. Hi-temp paint becomes it's own primer after being "fired" a little file work on welds and a couple applications could yeild a pretty exhaust which would be 1 easier on the ears, servicable, and easily "touched-up". Kudos G

I agree that more cuts in the pipe would quiet it down even more. I may end up making another one in the near future, so I'll be sure to experiment more with it to see how it turns out.

I used a sheet metal screw for extra security today, just in case it ever does come loose. My megaphone has three holes in it already, so I just used one of the existing ones.

That looks like a rather ingenious approach. Do I sense a business opportunity?

Now that's ingenuity! And hey, someone found a good use for those "orange" filters.

Good stuff! Very creative.

Best of success!