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Modifications to continuously variable transmissions (CVT) are presented in order to improve overall performance in recreational vehicles. A computer controlled CVT would eliminate performance-inhibiting compromises currently imposed by mechanical sensors and actuators. The authors propose a computer controlled CVT to obtain improved performance. This paper considers a snowmobile modification that is a stepping-stone towards a fully computer controlled CVT. External force was applied with a pneumatic cylinder and four bar linkage to the driven pulley to vary sheave pressure and override the natural shift pattern. An external force of 431 N increased track speed 59% during hill climb testing. Ultimately, a microprocessor would use input signals from track speed, engine speed, and throttle position to shift the CVT to obtain maximum performance.

In research conducted at Brigham Young University, four coatings were tested for their ability to increase the wear life of primary clutch sheaves made of A390 die-cast aluminum used in continuously variable transmissions (CVT). The coatings tested were: hard chrome, electroless nickel metal, hard coat anodizing and composite ceramic coating. A wear test stand was developed to duplicate wear found on CVTs currently in use. The wear was evaluated using four methods. The test first method characterized the shift delay properties of the worn CVTs while running on the wear test stand. As the CVT was run on the wear test stand a delay in shifting would develop during the unloading cycles. The second method used an ATV and chassis dynamometer to evaluate the change in performance with wear. The third method used a profilometer to evaluate the amount of material lost, through wear.