Worlds fastest snowmobile...and possibly the first powered by Porsche
 

I don't know that much about snowmobiles...but I figured that like a race car, big motor, light car is usually a promising combination. First, I sourced an available pair of thesehttp://forums.pelicanparts.com/uploa...1199152660.jpg
and set about fabricating the chassis. As the standard configuration for the 911 bases cars puts the engine in back, I had other reasons for facing it frontwards, first of which was cooling. With the motor facing forwards, the oncoming cool air would actually be driven into the fan, helping to cool the cylinders. The second and not so obvious reason was...well it actually looks cool. The engine is a stock (but good compression and leakdown numbers) 2.2 T with the standard upgrades...carrera tensioners, turbo valve covers running zeniths with 32 chokes. It ran well in the race car until I built the race motor.http://forums.pelicanparts.com/uploa...1199153031.jpg
Getting power to the snow smoothly was the next problem I faced. This motor is particularly torquey low end, and I didn't want to throw a major rooster tail every time I got on the throttle, and / or shifted. Most snow mobiles utilize a torque converter...which I didn't have. I decided that the shifting part was going to be a problem ...unless I ...yeah I know what you're thinking...pulled out the sportomatic 4 speed I had stashed away years ago for just this reason.http://forums.pelicanparts.com/uploa...1199153352.jpg
I had a spare 901 shifter lying around (which incidentally IS for sale) and after I mounted it up..gives new meaning to the description "short shift". http://forums.pelicanparts.com/uploa...1199153506.jpg
Next, I needed to integrate a throttle that was simple, yet ergonomically suitable to the beast being created. The throttle linkage that connects to the bellcrank on the right side of the trannie happened to be in the perfect location...mounting the throttle pedal was a snap.http://forums.pelicanparts.com/uploa...1199153658.jpg
I figured that as this was going to weigh in close to 450 lbs, brakes were not going to be a necessity... however, steering was. I remember from my last experience with a snow mobile, that at low speeds, steering was awful, at medium speeds ...bad, and only at high speeds was the steering approaching "acceptable". I was also never keen on the handlebar format, and since my throttle would be foot operated, I could do away with the handlebar "squeeze throttle" and go with a standard steering wheel. I just pulled a brand new Momo Competion out of storage and with some simple engineering...completed the steering rack and installed it.http://forums.pelicanparts.com/uploa...1199153994.jpg
While loose at the outset, with some adjustability, it tightened right up. I finished up the chassis, and mounted the skiis...now fully operational...and steerable. You will notice that the chassis is somewhat unconventional. It actually borrows from the aviation industry where during the first and second world wars, steel was a scarcity, and wood airframes were pushed into service due to the availability, flexibility, and forgiveness of the material. I had the wood ,and decided to give it a try. If it seems "boxy", and unstreamlined, remember, this is a prototypehttp://forums.pelicanparts.com/uploa...1199154308.jpg

Time for a road test...or in this case, a driveway test
 

I have a rather long driveway, which at my altitude in Colorado usually looks like thishttp://forums.pelicanparts.com/uploa...1199154484.jpg
with one major lefthander out to the county roadhttp://forums.pelicanparts.com/uploa...1199154555.jpg
I would have to get on the throttle quickly to get the steering up to speed, clear the chicanes (suvs) in the driveway, around the right hander...http://forums.pelicanparts.com/uploa...1199154658.jpg
Then after a gentle right...accelerate hard up the hill to have enough speed to hit the lefthander and out to the road. We have had high winds and a lot of drifting snow recently, and while my trucks have very different characteristics "plowing through the packed drifts, they inevitably get "high centered" due to weight of the truck forcing the narrow wheels into the drifts. This shouldn't happen if I can keep the speed up and the skiis on top of the snow.
He emerges from the shop...
looking somewhat tentative http://forums.pelicanparts.com/uploa...1199155081.jpg

You can see what the design has borrowed from other sportshttp://forums.pelicanparts.com/uploa...1199155285.jpg
Initially it was difficult to start, which I attribute partially to the cold, and the fact that it ( the motor) had been mothballed for several months. Just to check out the engagement of the motor and sportomatic, I gave it a little throttle and moved it off the garage apron..."first tracks." http://forums.pelicanparts.com/uploa...1199155494.jpg
AS the proud father...I had to take some completion photoshttp://forums.pelicanparts.com/uploa...1199155617.jpg
http://forums.pelicanparts.com/uploa...1199155659.jpg
As you can see the fan blades look almost stationary...it idles really low, like maybe 5 rpm (no thats no typo!)...very quiet, unlike a lot of two stroke snowmobiles.
I made a couple quick passes up the driveway...way too much power...really need to feather it in the turns. Surprisingly, ther was very little chassis flex or roll, which I totally attribute to the wood used in the construction. :D
More later on the high speed "shake-down"...http://forums.pelicanparts.com/uploa...1199156262.jpg

Dude, you are seriously nuts!

Great, now a porsche motor is going to be featured on the next "you know you're a redneck when" web site. :p

Yeah!
The steering wheel is facing the WRONG direction!

That bailing wire doesn't look too stable, have you considered duct tape instead?

I guess I missed the memo

It's very original, I'll give you that:D

I think you would have a better hole shot with a Nichol plated cogged belt . I bet you are under 9 sec . right ?

Way too much time on your hands!

:)

-Wayne

That's pretty cool Lars. It gives me more incentive to get the car ready for it's new tranny. Not sure how the skis are going to work down here in the sand, but I'll figure something out. But seriously, step away from the paint thinner. You're even building one of your cars upside down!

I hate to break this too you but that is not the most powerful snowmobile... the factory mountain machines are all over 150 HP now, add a can for another 10 HP. Also, the first time you have to dig that thing out of a tree well you'll probably want to call in a chopper!

I do give it an A+ for the cool factor of the porsche power plant tho, way more reliable than Polaris and cooler than the Suzuki engines in the Arctic Cats... are you working on an altitude compensation system for it yet?

need to see you on that thing ....

Hmmmm,
Roll car over onto top, use engine hoist to remove engine, no laying down on cold shop floor to unhook everything. I like it.

I must give him an A++ for his dedication to get the beast to function correctly, as we know difficult they are to get running as it should.

If only you used Volkl skiis. Keep it German man. Nice crate.

At least he had the good sense to use a SKI design AND Rossignols....I woulda seriously upchucked if he was going to use a snowboarder design.

One thing...that particular model is soft in the bumps.

Knucklehead!

I especially like the seat...oh...wait....