Variable Speed Drive ?

[shokenore]

Do any of you know of a temperature controlled variable speed drive suitable for 12volts?

I can get something close from the day job but was wondering if there was something off the shelf that would be easier/simpler and probably cheaper?

Or are there any cars that use a variable speed fan for cooling or are they just on/off.

Ta

[Kiwisurfing]

The 1UZ v8 Toyota Soarers have a variable speed fan but at a catch, its run via hydraulics so would be a prick to retro fit as youll need to install the pump as well as the fan.

Im not sure if its the norm but my old celica (1996) had a 2 speed electric setup,fairly simple array of relays to make it 2 speed, so ild say most cars should have a 2 speed setup

[shokenore]

I was thinking along the lines of a two fan set up, but with better control than just on/off.
Back to the searching....

[Tankerman]

From memory, the heater blower on cars like Morris Minors and cars of that era had a variable speed control, if they had a heater that is!
I think it was called a rheostat. Probably available new now from the classic suppliers.
Just a thought.

[slobodan]

The stat is the control for your engine temp, I wouldn't have thought you needed precise control over the rad water temp, an on/off fan is adequate.
A speed controlled fan is overkill.
I know your day job, so I know your thinking.

[shokenore]

I know that it may seem overkill and I will struggle to find something off the shelf, however I want to try to get rid of the massive amount of heat sink after a long/hot/fast run.
This will be in addition to the main electric and viscous fan, but controlled and fused separately.

Back to the searching.

[wishbone]

You could use a dual temp fan switch plus the original fan switch to give yourself 3 seperate temperature 'zones'. Not truly variable but considering the water temp will only go from ~88 to 105 should give you enough flexibility.

I'm pretty sure twin speed fans are available. That would give you slow aux fan / fast aux fan / fast aux fan + stock fan.

I've got a dual temp switch to fit to my 3.0 - am planning to fit a radiator misting system for mountain climbs, but want it to switch in automatically.