Thanks a lot guys!
The drift to the left started when Olov shut the engines off, when the jet thrust disappeared the kick and driver caught the wind in 130+km/h and the unsharpened sled runners started sliding sideways on the hard ice track.
Three out of four of all jet kick sleds ever raced at any speed at Speed Weekend ended up crashed, we start to understand why now. The runners are very sensitive to the quality of the track and with bikes and cars tearing up the track with spiked tires it is almost impossible to run a kick sled without hitting one of those tire ditches and being thrown off course.
A new and more suited chassis will be built for the twinturbine engine for next year, so stay tuned!
The rut chasing problem you ski guys are having is common to a sled (snowmobile) with "single skeg" ski's in rutted trails where they want to follow an existing rut. When I'm going to ride mainly trails I switch to a "twin skeg" ski & that totally solves that problem. I've seen guys hauling a$$ on flat trails where a single skeg has taken the sled right out from under them. Due to the size of the ruts you're having to deal with there, you might need to build some super wide ski's to keep you on top.
Something else you'll want to look at is steering geometry. Modern sleds are set up with positive Ackerman to help them turn at low speed but that necessitates a lot of rider weight shift at high speed to prevent them rolling over. In your situation I would be inclined to zero the Ackerman to the length of you vehicle, that will also help prevent a hunting problem.