How to keep thermo fan on while engine is off

[MichaelR32GTR]

I’m just wondering if you are able to have the thermo fan on when the engine is off (ignition on reds) to cool the engine after a race etc or until coolant temp drops below a pre defined value 

 

ecu is a link g4+ fury in a r32 gtr with a spal 16” engine thermo fan 

[Confused]

Do you have an electric water pump? If not, then all you're really doing is cooling the radiator - whilst yes, one hose is still open to the engine, the cooling effect won't really be as substantial as it would be with the coolant flowing around the engine.

[Adamw]

Yeah I was going to say something similar.  100 years ago when cars didnt have thermostats and they had 1/2" dia tubes in the radiator core with a very simple cooling circuit, you would get significant "thermosiphon" effect - in fact many didnt even need water pumps back then...  But in todays engines with complex flow through the heater system and bypass etc, thermostats, restrictive radiator, you will get almost no siphon effect. 

You can certainly do what you ask, but will need to rewire the ECU as per the "ECU Hold Power" diagram and I dont think you are going to see much benefit.  

[Dean]

You can increase the RPM Zero Timeout to its maximum (225 seconds) and leave the ignition on after stopping the engine too. But as mentioned above, it's a little useless unless running an electric water pump. 

[MichaelR32GTR]

Thanks guys