I have a fair bit of clutching experience on polaris trail sleds and we also run a 1000 ps amd a 1000 om with a 990 htg that runs 4.8's on ice......self-admittedly limited deep snow experience. If you run heavy wts and a big helix off the start to load the motor enough to prevent trenching, if i'm reading you right, your motor is overloaded and thus track spin is reduced??? Yes, that is possible. Then falling off the start angle .36 inches up the helix allows the engine to recover?? Ok now I can see this working. I know that carls uses helix's in the 60 degree range and maybe that is why. A rapid upshift out of the hole does get the belt out of the start position in the primary clutch resulting in less slippage....basically what polaris adopted years ago on stock helixs. Does somebody have a clear explanation of this high-angle startup?? One thing you said that caught my attention was the use of the same helix on different engines. The best performing helix I ever used in a xc800 polaris was a 46/34F for startup, middle and top and still work in a couple feet of snow. Surprisngly, we use the same helix in our 990. It sixty foots under 1 second and is in the 135 range in 660. We use a $30 drive belt because its softer and narrower and we throw it out after 10 runs. The reason the helix works in both sleds is that it is torque-sensing....the more belt pull applied to the secondary, the greater the side force and the greater the ability to upshift. Well, i've side tracked abit....appreciate all the info, clutchman and everyone else on this forum.
