How do you cool you motor in between passes?
I am having a hard time finding any info on them , but ShoGun industries made a Tik-Tok sequential switch for electric fan / water pump combos.
We used one for years in our last car.
It would run the water pump for 30 seconds , then run the fan for a minute...........it repeated these cycles until you turned it off.
Our car would go from 210 degrees in the late rounds to 160 in maybe five minutes.
I really liked it , but I don't know if Sho-Gun is still in business anymore.