Inline water pump on turbo endurance build

I have a mk3 supra that I will be 24h endurance racing. Issue is that the turbo will suffer during Pitstops as the engine has to be shut off. I was thinking about adding an inline electric water pump to keep the coolant flowing during a pitstop. Question is where in the plumbing to place it and whether to run it though the full loop or a seperate small turbo loop? When running through the full loop it will have to pump through the standard pump as well which will be blocking right?

Why don't you remove the impeller from the standard pump and just use the electric pump for all flow. I do that on my mazda 2L MZR powered sports racer.

I kind of want to the original pump as a safety measure, it's endurance racing after all. But if there's no other clean solution I'll probably try that.

You are more likely to have a failure of the OEM water pump than the EWP if it is being run at high engine speeds and with another pump in the circuit. Most OEM water pumps are optimised for operation around idle and cruise, with running at higher engine speeds resulting in cavitation of the pump impeller.

The cooling circuit in a hot turbo CHRA will often have a siphon action as the coolant in the system cools and loses pressure, drawing fluid through the CHRA.

If you are not on the throttle in the pit entry and lane, the turbo can shed a lot of heat in this period as well, how long are you stationary for in the pitstop?

That's interesting, thank you!

It will do refueling so can be up to a minute, (very slow pumps) fuel stations are right at pit entry so no cooling unfortunately. Then it'll drive 200m to the pitstop lane itself and stand still for up to another 30 seconds for tires and driver change. In the past we were allowed to keep the engine running if it's turbocharged for this exact reason, but they changed it unfortunately.

The engine will only be running 300hp so it's not much over stock, redline will be kept as original as well.