I don't know that I would go that far. VES is a variable exhuast system. The parts are essentially a bellow, and a guillotine slide valve. The pressure that builds up in the bellow is used to move the valve up against a spring which pushes it down, the valve covers or uncovers part of the exhaust port. Port height is one of the determining factors of the behavior or a 2-stroke engine. A high port height means that you would have a strong top end, but that the low end torque was non-existent. If the port were set low, you had a very strong low end, but the motor began "gasping for air" so to speak at high RPM. The VES system's valve changes the overall height of the port depending on combustion pressure. This allows the engine to have a low port at low RPM and a high port at high RPM. What actually provides the power gain is that the designers can move the port higher up than a non-VES motor, allowing for an even stronger top end pull, while minimizing the losses on low end. Generally, the motor with VES will have more power, but that doesn't mean that non-valved motors aren't worth looking at. Sleds without VES are generally cheaper to buy and are able to run the cheaper grade of oil (not that it means you should run garbage oil either. . .) Generally, the valves will net you up to about 10 hp on a given motor. The valves DO require a premium oil however, so figure that into your cost deliberations.Originally posted by xlt580man
[br]You would be wasting your time with a sled thats none ves.
The VES valves could have no effect on high RPM running because at WOT, the valves are pulled completely out of the port, which means they are no longer affecting exhaust flow, which means they are effectively not even there. If the valves were removed and the holes plugged, the high RPM of the power band would show no change. The low end and mid range are what would suffer.