It takes very little to put a trail machine on the race track. A special
made track of flat rubber, 40-durometer replacement for the lugged standard
track is needed. Skis are made with wheels in them.
As a baseline, a late model standard 800cc triple cylinder engine
snowmobile with asphalt track and skis on it is capable of running mid 10s
at 120 with a 160-180 lb. driver. It takes a fair amount of test and tune
time to find the right clutch setup to run those numbers, but those times
are achievable without any engine modifications. A typical 800cc stock
snowmobile makes 140-160 hp.
We have several snowmobiles competing on asphalt where I live in NY
State. There are many sleds running 9s, some of them running low 9s at 140+
mph. These sleds are not trail machines. They are typically what would be
considered "pro stock" sleds in grass racing. They feature
lightweight chassis and full race engines of 1000cc or more. 220-250 hp is
The sleds launch fast and hard; no shifting, no balancing, and no
sidestand to hold them up in the staging lanes.
Auxiliary cooldown carts are needed. I use a cart with a bilge pump and a
small car radiator/fan on it. After a run, hook up hoses via quick connects
on the cooling system circulate the water through the radiator and back into
I run an "improved" stock 700cc sled. Improved stock means a
modified engine and stock chassis. It runs 10.5s at 119 mph with typical
60-foot times in the 1.42-1.44 second range.
Snowmobiles are very competitive in bracket racing. I dare say, more
consistent than a car or a bike. If the sleds have any disadvantages, it's
in the reaction time. There are no 2-steps or trans brakes for snowmobiles.
Creative clutch work can help for a more consistent start, but they will
never be like a bike on a 2-step.
If you're interested in knowing more, email me. I have tons of digital
photos of how to build and set up a sled for asphalt or visit the rpm.net
web site in my signature line.