The CVT is a fun project to work on. There are alot of pros and cons with the system though. One of the biggest problems with ANY CVT is that they are not very effiecient. This is actually counterdicting our philosophy of creating the most effiecient drive possible which is our single speed timing belt system.
The toroidal and ball CVT's we worked with handle alot of torque however they are not very efficient in that they have alot of parasitic loss on the energy required to drive them. They also require a elastohydrodynamic fluid which changes properties as it is passed between contact points. It basically turns to a solid at the contact point which greatly raises the traction. The problem in this type of CVT is you now must have a totally sealed gearbox. You also need to fit in a mechanical mechanism which changes the rotational axis of the balls which is operated by a type of centerfugal clutch. The cost of doing this will most likely the put it out of our price range. The cost of the prototypes have almost put me living under a bridge.
IVT's are much more efficient at transfering torque however they do require alot of space because of all the planetary gears involved. The torque ratings are through the roof but the high speed gear ratio will not fit our application. We didn't even bother with this one other than exploring it within our drawings.
So what we are left with is the standard ole Variable Diameter Pulley (VDP) type of CVT. This is the most common CVT we see. We can get the cost down because it not a nightmare to machine and it works well. There is a fine line between belt tension vs max torque vs efficiency vs belt life that we are working on. It's a statistical nightmare. Imagine trying to find the perfect point where the belt is tight enough were it can handle the torque from a ONB 30.5 without slipping BUT not so tight that it creates so much friction that the efficiency drops to the floor. That friction also reduces the belt life. A custom belt we had specially made helps widen out that fine line.
I'm not really worried about anybody coming in and beating us to the release. Building a car around a CVT is a walk in the park. Building a CVT to fit a car is a PITA. Building a CVT to fit a car where it isn't sticking out like a sore thumb is even worse. It also helps if you have the only the only variable speed belt in the world, made from the right materials, at a length not currently available unless you machine a custom mould, sitting on your desk.
Also we've come a long way since the first single speed belt drive and the final product should be bullet proof. I actually prefer it over running the CVT because it's maintenance free. It's also a great performance boost. Having a smooth lighter weight drivetrain defintely helps your top end.