[serialk11r]

Um, sorry I don't follow your pressure argument. The cooling loop is what determines the pressure given flow rate. Same flow, same pressure at the pump outlet. Less pressure=less flow.

By the way, 5-10hp is a huge amount of power for people who switch their exhaust system to get maybe 1-2hp. Name another place where you can free up 5hp that easily. The majority of sports cars have 7000rpm on the tach, several have 8000-9000. Even high displacement American V8s that only hit a bit over 6000 see freed up power from an electric water pump.

As was pointed out, electric pumps for even big V8s only draw 6A, which is 72W. Going by 10hp~7000W, you can see that this means the water pump is flowing enough water at below 25% of the power peak revs, aka your water pump never needs to be spinning faster than 1500rpm * whatever the pulley ratio is.