Build A Faster Car - helping drivers engineer

First off, great site! Once these forums get moving I can see myself spending a lot of time here, and learning quite a bit if it's anything like Stretch's tech articles.

I'm searching for a formula, if one exists, that shows how many horsepowers would hypothetically "gained" with each pound of sprung weight that is reduced. Searching with Google is only turning up power to weight ratios and estimated quarter mile times resulting from mashing HP and vehicle weight, that is, among the massive amount of weight loss helper sites.

Any help will be greatly appreciated.