The specs for the EOS 40D says 6,5 fps. But think I have read/heard the that is only with battery grib and 2 batteries (and off cause plenty of light etc.) I am going to shoot skiers and snowboaders in Austria)).
You should get the full 6.5 fps with one battery and no grip, assuming your shutter speed doesn't preclude that (i.e. if you are set to 1/4 s exposure, you can't get 6.5 fps!).
Nikon dSLR battery grips 'unlock' a higher frame rate, Canon gives you the spec'd fps out of the box.
My 40D is certainly the same speed with or without the grip and its extra battery. The only improvements the grip gives me are handling and battery life.
your shutter speeds needs to be faster than one would think, I think the magical number is something like 1/500 which I doubt will be a problem if you are shooting skiers though.