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Will depend on the type of mechanical fan, have heard old hard mounted stiff ones could pull 10-15hp at high rpm's. Next step was to make the blades flexible so at high revs they flattened out and wasted less power. Finally was the clutch fans, I believe at high rpm these also slip or at a minimum cool down and free wheel so are better again.

HQ355 wrote:Ok, so no one is realy saying to put a lower temp thermostat in so i'l just go ahead with the thermo fans, how much kw roughly do you gain from going from mech to electric fans ? I have the VT 220 kw badges on my motor and that's what I want ! Except mine will be at the wheels

230 atw wont be to hard to get. Got a figure now?

It's got the clutch fan atm, it made 209kw @ the wheels on the dyno. Tune wise there's 2/10'ths of FA left I'd say as it was played with a bit on the dyno. I'm not interested in a huge amount more as I like the reliability of the whole car and how it pulls like a school boy in everyone of it's 6 gears and gets awsome economy, but I'd like to know I'm getting every last kw out of it !

HQ355 wrote:Ok, so no one is realy saying to put a lower temp thermostat in so i'l just go ahead with the thermo fans, how much kw roughly do you gain from going from mech to electric fans ? I have the VT 220 kw badges on my motor and that's what I want ! Except mine will be at the wheels

If it doesn't have a 180°F thermostat in it, than I'd recommend fitting one.

Going from a mechanical clutch fan to thermo's there probably isn't a lot in it but something is better than nothing. Takes a fair load off the water pump bearings too which can only be a good thing.

i did a log of my 304 today to and from work 20min to half hour drive in light traffic few stop starts with lights 24degree day and never saw anything over 80 degree temps on the intake on the way home had the a/c on
should take it out and give it a hard time see what temps i can get it up to its got a 77 degree stat in it AU thermos and VS alloy radiator thermos are set to 92 temps will sit at about 84 cruising above 60 rest of the engine is bog stock
except for a set of extractors
dont know if its any real relevance to you and what sort of conditions your running under but thats just what i saw today

Thanks for that Daz, the temps don't normaly sit on 100, it's only done it twice while I've been logging, I may just throw a lower thermostat in and see if it makes a difference. It seems it has in your case with a std setup so then we'l know how it goes in a modified version !

Standard V8 thermostat is 180F/82C, they don't run as hot as the V6.

If its running significantly higher than that when driving then yes replace it. If its only going up to 92 when sitting/idling then its fine.

I wouldn't drop it down to a 160 thermostat like some do, that's too low.

NAhh, the standard V8 thermostat is a 190°F/88°C unit. V6 is 195°F

Fitting a 180°F unit has just become standard practice (or should be) for anybody in the modifying/performance scene.

Not unless they changed something with the late injected engines, as far as I am aware all Holden V8s '68 to '98 use an 82 degree thermostat as standard. Its not something that makes sense to change in different climates because, well, its a thermostat!

92 is standard from at keast VN onwards. I just fitted a new one to my VR and was labelled 91 flfunny enough.
And idling in the shed it sits smack on 90 all day.