Originally Posted by Rczr600rider
The snow flap doesn't just keep you from covering yourself and the people behind you, it keeps more snow circulating in the tunnel to help keep the hyfax lubricated and keep snow on the heat exchangers.
You're dead on about keeping the snow in the tunnel and making sure that it gets to the heat exchangers. Little to none of that snow will ever find its way back *inside* of the skid to get to the slides, though. They don't need to be kept lubricated - they need to be kept cold. And, they get all the cooling they need by the track actually being in contact with snow on the ground. As the track slides over them, small amounts of snow are brought up inside the skid to cool the slides. Once the snow passes the rear of the skid, however, it is being flung *away* from the skid.