Phx Wheels Bug

Hello guys!

I have a problem with the phoenix wheels pack.
All phoenix wheels are sinking in the ground when speeding up.
This problem is very annoying because i cant build cars with phoenix wheels, because they are all sinking in the ground.

Here is a screen shot how it looks like.

http://img117.imageshack.us/img117/494/24798965.jpg

This is going to go in the Contraptions section, not the Lua section.

Also it has to do with the collision system in the engine. Usually increasing the wheels weight or not making the wheels spin faster than light.