Slash Cutting The V-Star
of the first things you probably wanted to change on your new V-Star is
the stock exhaust system.
The sound, or noticeable lack thereof, just don't seem to suit this beautiful bike.
Benny Bryant on the Shooting Stars ( Alabama Delphi Forum)described a radical modification to the stock exhaust system that Benny developed and tested.
This modification consists of cutting the end of the muffler off and removing the internal exhaust pipes and baffle plates.
The following diagrams show both a side view and a top view of a muffler that has had the initial slash cut completed.
The cut can be at any angle and at any distance from the end of the muffler given the following;
If you are *NOT* going to completely gut the muffler, then the angle and distance from the end of the pipe must be such that the second baffle plate *MUST* remain intact.
If you want to gut the pipe it doesn't matter where the cut is since all the internal pipes and baffle plates will be removed anyway.
JUST MAKE SURE YOU HIT THE SECOND BAFFLE PLATE AND DON"T GO THROUGH ONE OF THE BAFFLE REDIRECTION PORTS!
You can see the second baffle plate after the mufflers are slashed, you want the cut to be back a ways from the baffle plate.
Cut outside slash at 45 degrees and ended up about 3/4" behind, to the rear of the baffle plate.
The easiest way to make the slash cut is to find a local machine shop and have them do it for you on a horizontal band saw.
You can cut them yourself with a hack saw but it's difficult to get a straight and clean cut.
The machine shop route should cost around $15 Locate the position and angle of the cut and mark the cut line on the muffler using a felt tip pen.
Wrap the entire cut line with wide masking tape to prevent the chrome from chipping while the initial cut is made,however the chrome does actually hold up very well when the muffler is cut.
If going the machine shop route for the cut, I recommend protecting the chrome finish with wide masking tape.
This will help to keep the finish from getting scratched while clamped in the band saw.
You may also want to take a couple of blocks of soft wood to place in the jaws of the clamp, to further protect the finish
The first two diagrams show the 650 and 1100 V-Star mufflers in a, "sort of see through" view.
These diagrams are *not* to scale and merely intended to illustrate the construction and internal components of the mufflers.
The tags used to describe the components will be referenced throughout this write-up.
The following discussion will hopefully provide a basic understanding of the internal construction of the V-Star 650 exhaust system and the steps necessary to modify the mufflers to get 'that sound' you're after.
This picture shows the muffler mounted in a horizontal band saw with the slash cut about half way through the body of the muffler.
|Here the end of the muffler is shown that
has been cut away from the main body of the muffler.
This picture shows the Double Body Wall, Final Exhaust Pipe and the First Baffle Plate at the very tip of the muffler.
This section is disgarded.The view after the muffler has been cut.
This shows the Second Baffle Plate, Inner Exhaust Pipe and the Final Exhaust Pipe (the angled pipe that is cut off). This muffler has been 'Down Slashed'. Note the holes in the baffle plate.
These holes redirect exhaust gasses from the Final Baffle Chamber into the Inner Baffle Chamber.
|The following diagram
shows the side view of a fully gutted down slashed muffler. All internals,
pipes and baffle plates have been removed up to the Fourth Baffle Plate.
The Fourth Baffle Plate and the Primary Exhaust pipe remain untouched.
The Double Body Wall may be removed or not. If you side slash the mufflers then the Double Body Wall is really noticeable.
You don't really notice it if the mufflers are down slashed. It's a matter of taste.
Details on how to go about removing the wall lining are discussed below.
They sound more like aftermarket drag pipes but probably deeper because of the volume of the stock muffler.
The greater volume of the stock gutted muffler over a drag pipe, gives the exhaust gasses time to expand.
This effectively gives you a deeper more mellow sound than straight 2" drag pipes.
|Below is a diagram .The thought process,...
If you stop with just the initial slash cut, you effectively
have what's known as a stage 3 muffler mod.
With the stage 3 mod, you remove the End Cone and the First Baffle Plate.
You then would break the Final Exhaust Pipe out of the Second Baffle Wall.
Breaking the Final Exhaust Pipe out at this point is for appearance only.
By removing the First Baffle Plate there is *NO* redirection of exhaust gasses,... just straight out the back.
For example, Exhaust gasses enter the muffler through the Primary Exhaust Pipe into the Primary Baffle Chamber which doesn't do to much for the sound level.
Then the exhaust travels through the Inner Exhaust Pipe, bypassing the Inner Baffle Chamber and out the back of the muffler.
In effect what you have is a 1" drag pipe with a little muffling effect at the open back end of the muffler. It's high pitched and 'cracky' sounding.
the initial slash cut is made, use a Dremel rotary tool to cut the Final
Exhaust Pipe off and grind it down flush with the flange on the Second Baffle
Use the fiberglass reinforced cut off wheels to do *all* the cutting and grinding.
They cost more but the regular ones don't last at all.
A Flex Shaft attachment for the rotary tool makes the job a lot easier because you can get the cut off wheel into much tighter places.
In fact, you'll need the flex shaft attachment to cut off the Inner Exhaust Pipe.
As the cut off wheels get worn down to about 1" in diameter, remove them from the Dremel and replace them with new ones.
You'll need the 1" ones later on to cut off the Inner Exhaust Pipe.
off the Inner Exhaust Pipe but left about 1/8" sticking out beyond
the Second Baffle Plate.
You'll need this 1/8" 'lip' on the pipe to grab onto with needle nose vise grips.
|Cut off the Inner
Exhaust Pipe inside the Inner Baffle Chamber to allow the baffle chamber
to be used to tone down the volume and give the exhaust a deeper sound.
By cutting the Inner Exhaust Pipe off inside the baffle chamber you effectively are re-using the chamber as an exhaust expansion type baffle.
The gasses no longer have a direct path out the back of the muffler but have a chance to expand and make better use of the muffler.
the Inner Exhaust Pipe off inside the baffle chamber use the Dremel Flex
Shaft Tool and the 1" worn down cut off wheels.
Make sure that the cut off wheel is sufficiently small enough to pass through the pipe. Turn the Dremel on, adjust for moderately high speed and *SLOWLY* insert it into the pipe as far as you can while maintaining control of the tool end with both hands.
Try to stay away from the pipe walls until you reach the cut point, then begin to cut the pipe.
WEAR GOGGLES OR GLASSES to protect the eyes! Go slow!
Once the pipe is cut off all the way around on the inside, grind away or cut the spot welds between the pipe and the Second Baffle Plate.
Use the needle nose vise grips on the 1/8" lip and pull the pipe out.
To remove the Double Body Wall use the Dremel, again, to carefully cut it out around the entire perimeter of the muffler.
Leave about a 3/4" width ring of the double wall in the muffler.
This 'ring' is spot welded to the Second Baffle Plate in four places and will have to be removed one section at a time since you can't get to the welds to grind or cut them away.
Be careful when cutting out the double wall.
If you cut into or grind the main muffler wall it will be noticeable when you're done,
especially if you paint the inside with aluminum instead of black.
the double wall ring, first make a very sharp chisel out of an old flat
Ground the flat blade to a sharp edge with the Dremel tool using the flat side of a cut off wheel.
The spot welds holding the wall to the baffle plate are evenly spaced at 90 degree intervals around the perimeter of the ring.
The diagram above shows the spot welds but the exact orientation may differ from muffler to muffler.
The diagram is for illustration purposes only and is not in scale detail.
Notice that the 'Cut Here' mark is located exactly between two of the spot weld positions.
Use the chisel, starting on the ring's edge and between two of the spot welds, to cut the ring from the outside edge down to the baffle plate.
Cut the ring in four places so that you have four large tabs, each held in place to the baffle plate by the spot weld at the bottom center of each tab.
Grab each tab in turn with needle nose vise grips, and wiggle back and forth until the tab breaks off at the spot weld.
What you should be left with is four barely noticeable spot welds on the baffle plate.
Be careful when cutting the ring with the chisel that you don't cut or gouge the main muffler wall. You're almost done!
Clean up the slash cut with a small file and a couple of different grades of emery cloth.
Use very fine emery cloth to smooth the main wall edges and to sand smooth and clean the exposed areas inside the muffler.
Paint the baffle plate with high temp black and the exposed main muffler walls with aluminum high temp.
Attach two fender washers to the front of the baffle plate, over the holes directly in front of the Inner Exhaust Pipes .
Use large toggle bolts behind the baffle plate to hold the fender washers in place.
The threads of the screws into the toggle bolts were dipped with high temp RTV to act as thread lock to keep the washers and toggle bolts in place.
This makes a *big* difference in the sound.
The problem is that the exhaust gasses are still blowing out the back, directly through the hole left in the baffle plate after removing the section of Inner Exhaust Pipe, and by plugging the hole, the exhaust has more time to expand before exiting the muffler.
This part is strictly a matter of taste.
Put the fender washers in after reinstalling the exhaust system and checking it out.
It's a little work to do this modification but the results are awesome.
Mechanics (not a Yami dealer) tells that the stock exhaust system would last up to three times longer and was much better quality than many aftermarket systems.
I don't know if this is true, but it was nice to hear .