Since the VW/Subaru swap isn't going to use a standard sized radiator I was wondering what would be the safest way to make sure the car stays at optimum temps. Has anyone run thermatic fans with controllers and or Electric water pumps here;
The sales manager of Davies Craig happens to live in the same building as my car is parked and reckons it is worth using a Combo of EWP and thermatic fan controllers;
http://www.daviescraig.com.au/ 

I reckon this is great idea, as I could feel safe running a smaller radiator and getting the EWP to pick up pace and fan control to up the cooling speed for all conditions.

Thoughts?

I run a standard subaru pump plus a Davis Craig pump at the front end- works well, but it's big radiator ( 5 series bmw- cheap, long and fat but not tall)

If you go to a smaller radiator and increase the flow though the water wont have long enough in the radiator to cool.

The electric pump will definitly restrict water flow when it's off.

You're really over complicating it for no reason.

The stock water pump is more than adequate and it's a sealed system so it doesnt matter how big the rad is, its only moving water from one end to the other

The stock thermostat does an awesome job of getting the engine to temp real quick and maintaining a stable temp. even in winter mines up to temp in about 5 mins.

Are you using standard engine management?
They control the fans perfectly too just works on the temp coming out of the engine not 4 meters down the pipe line at the radiator.

I can see two sides of it here.

For the Suby motor, the stock water pump is very good. The stock genuine thermostat works well too. All works in our bus.

In regards to the DC Electric water pump I have in my other car. They are throttled by the controller based on the temperature reading. So the water pump becomes the thermostat. They are a DC motor, so they will infinitely vary the speed according to the cooling requirement. They don't restrict the flow.

It is a good question about fast water going through a radiator not having time to cool, but lets use some physics here, and understand that fast water wont have time to heat up as much in the motor either. Heat transfer works both ways, so speed of the water flow should have the same effect on transfer to the water or away from the water.

I use the standard water pump with a huge Camira Radiator, holds 16 Litres of coolant in total. i have been unable to boil the water on the street, freeway or track. There is absolutely no need for an electric water pump.
regards
jak

^ what he said, total overkill.

Subarus do have an issue with rev vs flow, but this is easily fixed by welding an inlarged outlet pipe onto the front of the thermostat housing. That said, I think it's more of an issue for the 6cyl than the 4cyl.

Yeah but is it overkill or having more control? What about thermatic fan control - so that you could program progressive cooling with variable fan speed from 70º up?

If you design the cooling system right the fans hardly come on anyway.

In the first 1500kms I put on mine the fan turned on twice and both times it was sitting in crawling bumper to bumper traffic.
Natural air flow does the job quite effectively.

The stock management doesn't call for the fans until 95-98c depending on the model so if your running them below that you're only wearing out the fans and wasting power for no real gain.

Not trying to poo poo your idea, just saying the stock setup had been proven time and time again,
Jaks bug has over 6 years and 174,000kms with who knows how many track runs on a stock cooling system.

Good to know - Cheers Joel - and yes I'll be running stock ECU.