Jump to content
Sign in to follow this  

My custom exhaust, DR650

Recommended Posts

Whats up guys, sold my DRZ a few years ago and missed it ever since.  Found a good deal on a DR650 so I jumped on it.  Of course it needs tweaks, exhaust is first.  I have an FCR and some bandit 400 wheels waiting to be worked in as well.  Below is the post from ADVrider on the exhaust.  Not sure ADVrider is the best place for ACTUAL "mods".
Well, here it went.  This was one of the most plugged up mufflers i've ever brutalized.  Anything I end up doing will be an improvement.
Weight was about 12.5 pounds
I started with cutting the end cap off.  clean cut so i can easily weld this back on.
I then cut around the weld holding the canister to the funky shaped chamber.  a little tab was holding it together so it needed to be cut, then the two half were free.
a look down inside the funky shaped thing! and a look at the dead-end baffle the exhaust smacks into before it finds its way through the holes and towards the exit.
next i started banging on the baffle to see if anything moved, and it did!  the whole thing just started sliding out the open back end of the can.
next was a surprise, the guts of the can came out in two pieces!  this wasnt a result of trauma either.  my thought is the design of the chambers and baffles traps a lot of heat in the center where it has time to screw up the metal.  add temp cycles and moisture and you get a muffler that looks like this. crazy
this is a look down into what would be the rear of the can through the end cap.  you can just see yet another baffle in there.
and heres a look from the other end and another baffle or chamber
next came the most tedious part of this exploration; getting into the funky shaped part.  i started be grinding off the huge welded flanges on either side.
i had to grind down all of the other welds globbed up on the sides.  they were welding the ends of the 3 rods going through to each side, holding it together.
next came a lot more grinding, prying, and cussing until i finally got the halves to let go.  i'm pretty confident these are the first ever pictures of what the hell is inside that thing!  what do you know, another dead end baffle!!
i may order a piece of stainless to replace this funky shaped chamber, that or just run a tube straight through it and leave all of the factory mounts in place.  I think i can source some perforated tube for the canister and some packing.  Snack time, more later...


Share this post

Link to post
Share on other sites

Aight! had a chanced to make something look like something today.  First, I knew all along i wouldn't be able to bend the tubing on account of it being thin walled, but i tried anyways.  sure enough, it began to wrinkle right away, so i bailed on that and tried to use what little bend i got to make the first two pieces.

1-3/4" and 1-7/8" .065 wall 304 stainless


cut the clamp off so i can re-use it on the new joint later


cut the flange off to allow the 1-3/4" tubing to slip over the stock header




First piece!!




few more:


plenty of clearance.  you can see the joint where the 1-7/8" slipped over the 1-3/4".



few more...


Cut out a new can end cap (rear) from .075 stainless


some ghetto rigetronomy to get things straight and aligned how i want them for tacking the can on:


tacked up:


the only thing i dont like about my idea is how short the can part of the stock muffler is but with the side panel on it hides it pretty well.


time to seal it all up and weld weld weld.  my plan is to scavenge a few of the factory mounts off of the stock exhaust and reuse them for a trouble free mount-up.  more later



Share this post

Link to post
Share on other sites

Create an account or sign in to comment

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

Reply with:

Sign in to follow this