Jump to content
The mkiv Supra Owners Club

Can someone explain hydro fans?


Guest AlanHutchinson

Recommended Posts

Guest AlanHutchinson

As above. My car sounds like a twin turbo hair drier! Can't find any decisive information on how the system works. The reason I am not sure wether it's the clutch itself or not is because it's intermittent - sometimes the fan is pretty tight. Yet sometimes it feels normal. Am I right in thinking there's a solenoid somewhere that controls it?

 

It's a 1jz by the way. If that makes any difference.

 

Thanks.

Alan.

Link to comment
Share on other sites

As far as I know it shares and runs off the power steering pump. The PAS pump does little save when manoeuvring, so for whatever reason Toyota / Lexus decided to utilise it to run a small hydraulic motor built into the water pump casting and drive the engine cooling fan with it. A viscous fan drive *MAY* have higher parasitic losses over a hydraulic one, I just don't know, but it was a complex and costly way to go about things, for seemingly marginal reasons. Chrysler tried a hydraulic cooling fan on their sports truck, the Dodge Viper. It lasted one generation and was known to be troublesome. They reverted back to a more conventional system, tail between their legs. I think you can convert a *JZ hydraulic type water pump to conventional and get rid of it and run a viscous fan.

 

Most people have no comprehension how much HP a big cooling fan with the viscous coupling pretty much locked up due to high radiator matrix air temps consumes. They move *FAR FAR* more air then even the biggest electric fans, yet with the viscous slipping as it would on an open road, they draw very little engine power. It remains a mystery to me as to why people are in such a rush to fit (inferior) electric fans...

Edited by Chris Wilson (see edit history)
Link to comment
Share on other sites

Its a 1JZ, Chasers, Mk IIs etc came with the hydraulic powered fan like the Aristo set up.

 

arh harh , my bad I did not even know of such a system . everyday is a school day . I can see chris's point the simplest solousion is often the best

Link to comment
Share on other sites

I think the benefits can be gauged by the fact that Toyota used it on the V8 Soarer/SC, then dropped it for the Celsior/LS, on the Mk 1 Aristo but not on the Mk4 Supra, and on the Mk3 Supra/early Chaser family, but not on the Soarer/later Chaser. It didn't take them long to realise that the hydraulic motor, associated pipes, and an ECU were just a little over-complicated as a way of blowing air through a radiator...

 

Evidently, it was a solution looking for a problem. :)

Link to comment
Share on other sites

I like the hydro fan set up, its pretty clever and the fan is HUGE. But the water pump/hydro pump unit costs around 1200 quid to replace.

And yes you can ditch it and fit a standard JZ water pump, thats what Ive done. Problem is the fan shroud

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.