Post Forward 2010 M8

Normally i don't go through the effort of posting things like this up. But i really enjoy the fab build forums and figured i would finally give back. Hopefully i can add to the section and get some ideas pumping since the sled build section seems pretty slow this year. This build i did in the summer/fall of 2014 so its a little dated but i'll get to that.

When I did this I had been riding the 2010 M8 153 limited for 2 previous years. This sled literally opened up the door for me on technical tree bashing coming from a 2004 Rev and 2008 XP. However over time I felt I had hit a spot where i felt like the sled was holding me back in some aspects of my riding style. I didn't like how i had to be super forward doing downhill elevators so it didn't wash. I also was washing out on the super steep sidehills without doing the same. I felt like if my handlebars were farther forward than i could counter act this. I also always hates how the steering felt weak and would always deflect and twist even with the chromoly steering post, bdx steering bushing, and my own steering brace. I saw how some people on the internet had put earlier 440 sno pro steering on the latter, bigger M's and did as much research as possible all over the interweb.

From ones i could find it was with the earlier 2004'ish setup the geometry was horrible. The 2006 setup was interesting but I didn't like how the handlebar input to ski movement wasn't consistent(ratio), parts for the entire setup was pricey, and the steering plates left little room for the wiring. I was also unsure if it would facilitate retaining the stock intake which I wanted to keep.

I found a old worn out steering post with bottom plate from a 2004 sno pro on ebay and started assembling parts. For the most part i bought alot of things i needed instead of modding up what i had with the intent if the project was a complete fail i could easily revert the sled. Parts for these at the time were super cheap and plentiful on ebay.

Testing of angle of the steering post to minimize steering swing to how far forward everything seemed to take forever i ended up settling on the post angle of being roughly 55 degrees. It ended up being pretty close to a proclimb with a c3 3" post forward kit or a skidoo xm at roughly 15" height difference at the handlebar ends at full steering lock.

Next up was figuring out the steering geometry. After the first mock up it was clear that the original steering tab on the 2004 steering post was no where near the right for working with the bigger M8 chassis. I am fortunate enough to have access to some pretty high dollar machines at work so in the lathe the bell crank went to cut off the weld to reindex. The steering arm also got lobbed off the post and I cut out a bigger one. Well i actually cut out a few and the ones following were not nearly as nice. To get the total arm length perfect I made various ones 1/16" longer until I found the perfect length I was trying to make these pretty light duty and easy to make for mock up stage but i found that even with the sled lifted up anything light would just deflect which would change the steering characteristics. Might not have been a big deal for other but my OCD was kicking in.

One thing i will also touch on that I've seen others fail to notice is when trying to get to get linkage to be perfectly linear (equal output for your input throughout the entire range) you must make sure that at the 50% point of travel the arms must be parallel to one another. If you don't have this you more than likely will have some quirky steering.

After I had the steering geometry figured out I sent the mock up post to Kurt at Canadasledparts to have a copy made out of chromoly. I needed the mount slightly lower to make the steering force completely lateral and Kurt came up with a idea that worked out nicely. Makes the stock post look like a pile of garbage. Also some pictures to show the steering going through the motions

Then I moved onto the post mounts. Used a steering bushing out of a Skidoo Rev, Ebay'd a set of side support braces out of a 2009 SnoPro 500 that worked perfectly, and had a local metal shop cut out a design i drew up on the plasma table and bend on their CNC brake.

Next was figuring out the air box. With the steering post going through where the stock intake resides and coming out where the gauge would be some things had to be moved around. I didn't want to loose the stock air box because i felt the aftermarket ones were too much compromise. I didn't want to have to run a fuel controller and with the creek crossings i didn't want water ingestion to be an issue with the bdx/cutler setups. I contemplated using a F series intake that straps on the outside of the hood but many say they instantly plug whenever deep snow is encountered. After a little thinking i thought i would make my own. My plan was to utilizes one half of the hood intake and mold in the space where the right side headlight would be and draw air in from there. I did some research and desided to try my hat at vacuum forming. For anyone looking into trying something like that i recommend it as it is pretty easy. I used 1/8" thick abs sheet its cheap, easily form able with a heat gun for touch ups and looks pretty descent.

And finally finishing off all the small things to make it all work together.