When talking tunning of the cvt there is more to it then most realise. I like many others for years relied on others results. Polini and Malosi will tell you to change the torque spring only when the belt slips, not very scientific with buggies anyway. One thing is for sure the main purpose of the torque spring is to coordinate the clutch pulley with the variator. One night I googled tunning a cvt and come across 2 college grads synopsis on tunning a cvt. One grad fed into his computer the weights, dimentions, and, psi specifications then changing one or another spec to come up with his different results the other had the aid of not only the computer but also a dyno. These reports are so calculius you would think it was rocket science. I won't lie and tell you I understood everything but what I did get out of these reports were the torque spring basicallly controls the belt slippage. Pulley diameter, roller weights, weight of vehicle, tire size and weight, anything that affects the rear wheel HP will determine the proper torque spring to use. What the spring #'s are suppose to signify is a 1000 (stock) spring will engage 1000 rpm over minimum engine rpm rate. Minimum rpm rate is the minimum rpm the engine can idle without dieing. So if say the minimum engine idle is 400rpm the spring should start compressing at 1400rpm. This I am told is the measure used to rate the springs. Most of us started with lighter rollers and a 1500 spring but as you mod the engine and producing more HP the springs and or rollers will also need to change. Also it will depend on the type of ridding you will mostly do. True a stiffer spring will downshift faster but the more important thing is when you let into it again the belt doesn't slip. Belt slippage is the main result for variator face grooving and roller flat spots since slippage will very quickly heat up the cvt. To sum it up unless you have a dyno it will be a trial and error. Taking the suggestion of some one else as to what combo is right is a great starting point but then it is trial and error. I agree with GX150 on all but one point, that is slidders last longer than rollers. It depends on the material used and of coarse the heat of the cvt. A worn roller is easily judged by its flat spots however slidders wear as well on their flat slidding edges.< Are slidders better than rollers? Is dodge better then Ford?>( Its all a matter of ones prefference, thats my opinion and I'm sticking to it)
