That is certainly VERY fast. Oh my.
It depends on what kind of launcher you're using, but you can probably just take out the last stage entirely, which should leave you with a much more manageable 1:18 ratio. As far as I'm aware, at max power that's coming close to the height and distance limits on launched balls anyway.
(Personally, while using a wheeled pitching system my team's never felt the need to go beyond 1:9, and did very well at several competitions using 1:6. Really depends on launch angle and spacing between the wheels, though.)
There's a couple of posts here on the issue if you look back a couple months. This one in particular talks about the necessary speeds for certain designs as well as the safety aspect of running things that fast:
http://www.chiefdelphi.com/forums/sh...ad.php?t=78880