Originally Posted by
johnp38
Tombie makes a good point RRT
I have not used electric water pumps but what I found in converting (older) cars over to electric fans was the current draw idling in city traffic on a hot day with aircon on was always a downer.
Also the high volume of air the mechanical fan flows is also pushing its way around the engine and taking some of that turbo heat out under the car too.
And while I am at it, a twin fan factory setup from the wreckers is peanuts ( about 40 to 60 bucks around here) and is the most efficient high volume airflow vs current draw setup in my (not very humble) opinion.
You are drawing a lot of extra amps with the aftermarket electric fan/waterpump combo at idle.
How are you preferencing water flow through the heater core when you want cabin heat on a cold morning?
I would still put a thermostat housing (with a small bypass hole drilled in the thermostat flange or already built into the fitting) just after the branch off to the heater core then hose straight through to radiator top inlet (as I believe you would be eliminating/blocking the radiator bypass downpipe). This coupled with your lekky water pump set to a slow speed would draw through the heater circuit , initially pulling the warming water through and then as it all gets up to temp and thermostat opens you can speed up pump with your fancy controller settings.
My 5 cents worth