has anyone tried just underdriving the water pump (or all of the accessories), while leaving the main pulley on the EC on there? wouldn't this speed up the water pump/rest of the accessories, giving your more flow? or would this over-spin the water pump and destry it?

 

Most people want to slow the water pump down so it will not cavitate at high speed . Put a larger pulley on the water pump to do it . You should be good at low speed also because the pulley can not be big enough to slow it down to much .

 

Underdriving = slower spin rate

 

The waterpump would still be underdriven, not overdriven. Underdrive main pulleys are smaller than stock. Underdrive accessory pulleys (wp, alt) are larger than stock.

-Max