Delta Pag offers a controller that works great. I just recently wired it to where my EFI will control it via PWM but I haven't run it yet to see how well that will work.

I run the car really cool at the track so I like to be able to switch between "street cool" and "track cool" easier than doing it via the controller. 160* in the burnout box vs 140* in the burnout box is worth a tenth on my car. Having an electric water pump and fan make 140* entering the burnout box a pretty easy thing to achieve.