car runs better/faster after new water pump and accessory belt???

[Lil bastard]

The waterpump is about a 3hp parasitic draw when operating properly. If the shaft is turning at all, while it may draw more, it's not much more.

Hp differences of less than 10hp cannot be felt.

So while academically speaking you may have restored some power, in the real world, it's most probably all in your head.

Cheers!