WR450 exhaust mods

Well, I've decided to just go ahead and try it for myself. Here are some shots of the procedure. I did it a little differently then others here, but I'm sure the end result will be about the same. So far I think it's turned out pretty good.

I used an angle grinder with a zip-cut disc (3/32 thick)

Picture 1

Here is the end cap with the tip running through it.

Picture 2

Here I've cut away the end cap from the exhaust tip. I used a dremel and carefully cut between the end cap and the weld that holds the exhaust tip in place. (on the outside)

Picture 3

Picture 5

At this point you have to cut the pipe off between the weld and the loose end cap. Obviously so you can remove it. :-)

Picture 6

Quite a bit shorter! Forgot to measure it though but I basically cut it in front of the last baffle (or first if you are going from the exhaust tip)

Picture 7

This is the first baffle looking from the exhaust tip.

Picture 8

This is the new exhaust tip. After trial fitting I will be making some changes to it. First off the mitre isn't right and second, I don't like the fact that you can see the tip of the second baffle tube. You can't see much of it, but it is visible (refer to last image)

Picture 9

I cut the original tip out and used a piece from inside the exhasut to fabricate my new tip. Not quite long enough though so I guess I will have to buy a piece. I used a dremel to cut the hole to except the larger diameter tubing. Stay inside the line and use a stone of some sort to clean it up and get the size exact.

Picture 10

A shot from the back. As you can see, I need to lengthen or change the angle so you cannot see the pipe from the first baffle. I want to keep it forestry legal.

Picture 11

Picture 12

Nothing is welded yet so changes can still be made.

just wondering does there seem to be an increase in power and noise. did u do the airbox mods to make it better flowing all the way.

I've done all of the free mods except the gray wire. BTW this is on the 03 WR450. I will let you know how much louder it is and if there is any noticeable performance gains. I just did this tonight. I still have to TIG weld it back up. The way I've done it in the pictures eliminates one of the baffles. If you look at picture 11, there is a cross break in the baffle. The placement of the cross break is right in line with the exhaust from the header pipe. I'm assuming this was to strengthen for poping when decelaerating quickly. :cry:

good stuff! i'm going to do somthing similar to mine.

i've done the grey wire i think its better cut.

would i have to shorten the exaust?

If you want to take out the last baffle you will have to shorten it quite a bit. As I mentioned above, I cut mine just before the last baffle. If you look in the pictures you can see the piece I removed. All of it is welded so there's no easy way to remove it except to cut it. I would have liked mine a little longer, but I guess this way there's less to damage in case of a crash. :cry: A person could always add some to it. If you clean up the joint really well and purge the pipe with Argon, you can get a good quality (full penetration) weld so it can be ground right to the surface and polished back up so you wouldn't be able to see the joint. For now though I will try it like this. It can always be changed later if I'm not happy with the results.

Tested the mods to the exhaust today. I only have it tack welded together and I think I'm going to make some changes. I want to design a removable baffle that can be easily removed and replaced with a straight through exhaust. The mods I made, made a noticeable difference in power. Especially off the bottom. The power seemed much snappier. As for noise level... a fair bit louder then stock. The sound reminds me of a supertrapp silencer. I really like the sound, but it's a little too loud for around here. I don't want the neighbours to get excited!!! I also want it to be forestry legal.

nice work,

i guess the same can be done to the wr4 exhaust?

btw is there a pic 4?


I'm not sure if the internals are the same, but something similar could be done. As for the picture #4... hmmmm... not sure what happen there. It was late... :cry:.

you guys have way to much time on your hand I give you credit. I did all the mods bought a white bros E2 pipe change the main jet to a 170 removed the ais installed a IMS tank, the bike is so awsome now it takes off like a rocket. Its fun to ride now have about 200 miles on it also put a baja light kit on it to street legal it.

It only took a few hours. Besides, no one else will have the same exhaust... anywhere!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now