Alba's take: Your clutch in your RZR can be altered in a few ways to increase performance. Below are a list the ways and how they affect performance. Clutch weights: The weights in your clutch control your operating rpm. More weight = less rpm and less weight = more rpm. The key to the CVT clutch in your RZR is to dial in your operating rpm. The operating rpm is the rpm your engine is running at during full throttle. You want your RZR to hold that rpm for as long as possible typically from just after stab in to top speed. Being off just 400 rpm can be a 5 hp difference. Because of this we feel this is the single most important aspect of your clutch. EVERY RZR is a little different. If you have put bigger tires on or have added weight to your RZR your operating rpm has been lowered further lowering available power. To fix this less clutch weight is needed to raise your operating rpm. On the other side if you have added horsepower to your RZR your operating rpm will increase. Some times so much that your top speed will start to lower itself due to pre maturely hitting the rev limiter. To fix this more weight in needed. These weights have 3 positions to remove or add weight. The heel which refers to the bottom. The center and the tip. The weight placement helps adjust how your power hits. By placing weight closer to the heel your engine will respond quicker and hit harder. If you place weight on the tip it will hit softer and be less aggressive but more controllable. These will allow you to tune your car to your specific needs and will work for future mods with a re-adjust. We prefer to set most weight on the heel and center which gives maximum performance. These come with instructions and a base weight to get you very close. For reference a RZR 1000 makes peak power at 8300 rpm. If you are not running at that rpm your RZR is not using all of its available horsepower! Primary spring: The primary spring on your RZR controls the engagement rpm or stall. This is the amount of rpm's it takes for your RZR to engage the clutch from a stand still. We increase this about 500 rpm. We feel that this is the perfect amount for most riders and more becomes a nuisance. This gives you more hit from a stop and out of corners. Secondary: The stiffer secondary spring increases belt pinch helping to reduce belt slipping and increase belt life. We only use this on the rzr 1000. The RZR900 is set properly from the factory. Helix: The main difference you will notice when you change your helix is removing engine braking. When you let off the throttle on your RZR the stock helix adds engine braking which slows you down. We leave this an option and do not recommend this for most. Some people love it while others hate it. With out engine braking your foot is constantly moving from the gas to brake petal. Learning to use your stock helix with engine braking we feel is the best option. The quicker you let of the throttle the more engine braking will be applied. Let off the throttle softly and braking is less noticeable. Also blip or tap the throttle when you let off to lessen the effect as well. But if you don't want engine braking get the helix.