I have posted a few pictures in various other threads, but figured I’d make a new thread for the project since it’s something I would have liked to have when I was researching the project.
Goal was to modernize the axys chassis, especially since many of the reviews of the matryx said it was quite similar to the axys but the slash tunnel was one of the main reasons to get the new chassis. Since that’s not in the cards right now, I figured I’d try and work with what I have and slash mine to prolong its life as a modern mountain sled. I also had some cracking on my drop brackets, which I replaced last season with some welded plate versions, but it still wasn’t as rigid as I wanted because the aftermarket running boards did not have a means of supporting the drop brackets like the oem boards do (and the aftermarket boards do now). So since I already had to make a custom bumper for the taper shape, I rolled this feature in to the design, as well as supporting the mounting location of the running boards to the tunnel. This addition made the bumper design more complicated and required a good bit more accuracy to get the existing mounting holes for the boards lined up with the drop brackets, but it worked out. Also wanted to maintain stock coolant flow.
Started out by watching every video and getting every installation instruction to all available tunnel chop kits to see what could be done with existing cooling channel. Since I couldn’t find anywhere to sell a similar size of aluminum extrusion, I decided I had to use bits of the tunnel and shift them around to get the coolant flow to work how I wanted. Used CAD to model up the existing tunnel, cut it up and rearranged it to reuse the 90° back corners to make the flow continuous. Ended up settling on 8” shorter, and another 9” of linear tapered section. I also wanted it to look as oem as possible, so I wanted to use the center top sheet of the tunnel, which comes apart from the coolant channel after drilling out the rivets, in the tapered section.
Made some paper templates to make sure that was going to work right on the sled. Made prints for each section to be cut off and templated it on the sled. Iterated some templates to get the drop brackets and running board mounting holes to line up correctly for the bumper.
Decided that since there is so much talk of cooling issues with the slash, I should add a supplemental cooler too. Didn’t want to spend the money on a mtntk kit, so I found a used cooler from a ’03 Doo REV on ebay for $55 shipped. Got a Ø1” Napa coolant hose U for the series connection. Luckily the Polaris and Doo coolers both use Ø1” fittings, so it was pretty easy. Doo cooler mounting would have been straight through the Polaris cooler so I spec’d out some 3M permanent structural double sided tape that operates within my expected temperatures of ambient and coolant temps and had a tab welded at the back of the cooler for rivets as additional piece of mind. Used the whole roll.
Cutting the tunnel went pretty well with a carbide tipped skil saw blade for straight sections, dremmel cutoff wheel for small sections, and angle grinder with an aluminum slitting wheel for everything else. Used a small file or die grinder and scotchbrite wheels to clean everything up for welding. Had to cut all the extra material off around the coolant channels for a complete water-tight weld all around. Flushed everything well with air and water through the ports in front of the fuel tank. Everything fit up surprisingly well, and the lips of the stock cooler extrusion even mated up with the tunnel top sheet how I wanted. My friend TIG’d it all up. Worst part was probably welding within the T slot sections, which couldn’t be avoided like you could with a square tunnel chop (since the slots just go straight out the back). Had to hang the tungsten way out. Pressure tested first try though. Trimmed the tunnel to fit the bumper contours.
Bumper design was based on mounting locations for running boards and drop brackets with a big space for drilling through the tunnel and drop brackets to tie it all together. Wanted to reinforce the bend area since this section would be yielded by bending (hydraulic press) the bumper, so doubled up the plates in that section, and kept it going up to the handle since it looked cool. Plates are each ¼” 6061, which is certainly overkill, but since this is pretty structural up front I didn’t want too much flex. Drawings were sent out for waterjet for the 4 side plates and drop bracket feet. I wanted the handle high to be able to actually grab the thing when I’m stuck, and to be able to see the taillight under it while not extending far past the back of the tunnel. Handle had some compound angles and 3 sections of tubing required which did not go as planned so had to have a whole lot of weld to get it all made up. Doesn’t look the best but it’s strong and functional. Used a rattle can of primer/paint 2 in 1 for metal to seal everything up. Already chipping off after a few rides even with good surface prep. Should have done more research here. Mounted up pretty easily. Lots of clamps to make sure everything was seated where I wanted, then drilled and riveted everything up.
Oem taillight was way too big, so found a motorcycle taillight and drew up a little housing to 3D print. Sealed it up with silicon, spliced it in with marine solder heat shrinks, and covered the wires with a section of oem cover. Back of the sled looked pretty unfinished, so I made a useless snow flap to button it up. Tunnel bag was pushed as far forward as possible, but still needed the back corners trimmed off and new holes punched to work with the new location of T track in the tapered section.
Overall it looks and works as I had hoped. Everything is rock solid, tunnel and drop brackets are straight, and track is centered well. Sled cuts through the snow much more easily, and when I’m stuck its not from getting the tunnel hung up in the trench like before. Cooling works pretty well even on the trail, likely due to the Doo cooler addition. Tape on the Doo cooler is holding up well so far, which it should since its made for replacing bolts and rivets attaching panels to frame. I wish the paint would hold up better, but the sled is pretty well used at this point anyway so its not too heartbreaking. Whole project cost more and took way longer than I expected. Days longer. I probably wouldn’t do it again, and would opt for either just selling the sled and getting a matryx, doing the CR Racing tunnel taper kit ($1100), or a straight up square chop. But its done, its cool, and it was a challenge so I’m happy to have tried it.
Goal was to modernize the axys chassis, especially since many of the reviews of the matryx said it was quite similar to the axys but the slash tunnel was one of the main reasons to get the new chassis. Since that’s not in the cards right now, I figured I’d try and work with what I have and slash mine to prolong its life as a modern mountain sled. I also had some cracking on my drop brackets, which I replaced last season with some welded plate versions, but it still wasn’t as rigid as I wanted because the aftermarket running boards did not have a means of supporting the drop brackets like the oem boards do (and the aftermarket boards do now). So since I already had to make a custom bumper for the taper shape, I rolled this feature in to the design, as well as supporting the mounting location of the running boards to the tunnel. This addition made the bumper design more complicated and required a good bit more accuracy to get the existing mounting holes for the boards lined up with the drop brackets, but it worked out. Also wanted to maintain stock coolant flow.
Started out by watching every video and getting every installation instruction to all available tunnel chop kits to see what could be done with existing cooling channel. Since I couldn’t find anywhere to sell a similar size of aluminum extrusion, I decided I had to use bits of the tunnel and shift them around to get the coolant flow to work how I wanted. Used CAD to model up the existing tunnel, cut it up and rearranged it to reuse the 90° back corners to make the flow continuous. Ended up settling on 8” shorter, and another 9” of linear tapered section. I also wanted it to look as oem as possible, so I wanted to use the center top sheet of the tunnel, which comes apart from the coolant channel after drilling out the rivets, in the tapered section.
Made some paper templates to make sure that was going to work right on the sled. Made prints for each section to be cut off and templated it on the sled. Iterated some templates to get the drop brackets and running board mounting holes to line up correctly for the bumper.
Decided that since there is so much talk of cooling issues with the slash, I should add a supplemental cooler too. Didn’t want to spend the money on a mtntk kit, so I found a used cooler from a ’03 Doo REV on ebay for $55 shipped. Got a Ø1” Napa coolant hose U for the series connection. Luckily the Polaris and Doo coolers both use Ø1” fittings, so it was pretty easy. Doo cooler mounting would have been straight through the Polaris cooler so I spec’d out some 3M permanent structural double sided tape that operates within my expected temperatures of ambient and coolant temps and had a tab welded at the back of the cooler for rivets as additional piece of mind. Used the whole roll.
Cutting the tunnel went pretty well with a carbide tipped skil saw blade for straight sections, dremmel cutoff wheel for small sections, and angle grinder with an aluminum slitting wheel for everything else. Used a small file or die grinder and scotchbrite wheels to clean everything up for welding. Had to cut all the extra material off around the coolant channels for a complete water-tight weld all around. Flushed everything well with air and water through the ports in front of the fuel tank. Everything fit up surprisingly well, and the lips of the stock cooler extrusion even mated up with the tunnel top sheet how I wanted. My friend TIG’d it all up. Worst part was probably welding within the T slot sections, which couldn’t be avoided like you could with a square tunnel chop (since the slots just go straight out the back). Had to hang the tungsten way out. Pressure tested first try though. Trimmed the tunnel to fit the bumper contours.
Bumper design was based on mounting locations for running boards and drop brackets with a big space for drilling through the tunnel and drop brackets to tie it all together. Wanted to reinforce the bend area since this section would be yielded by bending (hydraulic press) the bumper, so doubled up the plates in that section, and kept it going up to the handle since it looked cool. Plates are each ¼” 6061, which is certainly overkill, but since this is pretty structural up front I didn’t want too much flex. Drawings were sent out for waterjet for the 4 side plates and drop bracket feet. I wanted the handle high to be able to actually grab the thing when I’m stuck, and to be able to see the taillight under it while not extending far past the back of the tunnel. Handle had some compound angles and 3 sections of tubing required which did not go as planned so had to have a whole lot of weld to get it all made up. Doesn’t look the best but it’s strong and functional. Used a rattle can of primer/paint 2 in 1 for metal to seal everything up. Already chipping off after a few rides even with good surface prep. Should have done more research here. Mounted up pretty easily. Lots of clamps to make sure everything was seated where I wanted, then drilled and riveted everything up.
Oem taillight was way too big, so found a motorcycle taillight and drew up a little housing to 3D print. Sealed it up with silicon, spliced it in with marine solder heat shrinks, and covered the wires with a section of oem cover. Back of the sled looked pretty unfinished, so I made a useless snow flap to button it up. Tunnel bag was pushed as far forward as possible, but still needed the back corners trimmed off and new holes punched to work with the new location of T track in the tapered section.
Overall it looks and works as I had hoped. Everything is rock solid, tunnel and drop brackets are straight, and track is centered well. Sled cuts through the snow much more easily, and when I’m stuck its not from getting the tunnel hung up in the trench like before. Cooling works pretty well even on the trail, likely due to the Doo cooler addition. Tape on the Doo cooler is holding up well so far, which it should since its made for replacing bolts and rivets attaching panels to frame. I wish the paint would hold up better, but the sled is pretty well used at this point anyway so its not too heartbreaking. Whole project cost more and took way longer than I expected. Days longer. I probably wouldn’t do it again, and would opt for either just selling the sled and getting a matryx, doing the CR Racing tunnel taper kit ($1100), or a straight up square chop. But its done, its cool, and it was a challenge so I’m happy to have tried it.
well done
