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Hi everyone!

Today, in deep conversation about GTR performance with one of my friends the topic of thermo fans came up. I was under the impression that thermo fans were far better than using the standard radiator fans. The justification of this opinion was the fact that using the standard fan sapped a bit of power (how much KW loss I am unsure).

My question to everyone out there is; Are thermo fans a worthwhile upgrade? Or will the standard fan suffice?

Those of you who are running thermo fans I would like to hear your opinions.

Thanking everyone in advance.

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My experience is you probably need to do a lot of extra engineering to block off all routes except through the radiator for the cooling air.

In my experience, the risk of overheating / cooking the engine is not worth the couple of extra kW you gain.

I use 2 14" davies craig thermo fans, its a tight fit. I havent made a shroud of anything for them yet but even under hard driving the temp only goes up a degree or two. On hot days stuck in traffic the temp gauge doesnt move.

My experience is you probably need to do a lot of extra engineering to block off all routes except through the radiator for the cooling air.

In my experience, the risk of overheating / cooking the engine is not worth the couple of extra kW you gain.

But in terms of efficiency, isn't the fan of minimal use when travelling faster than 60km/h?

Also, what about all the FWD cars that run electric fans from factory?

Cheers

like above, fans are used the most when sitting in traffic. They only really shine, when its 30+deg and you arnt moving.

Hell my old '79 holden used to love driving on the highway (cold temps), but go through Maccas on a hot day and it would shoot up temps :)

Thermos NEED a shroud to pull air through like the std setup, or they arnt worth much imho. Ive seen it on heaps of cars now with themos that cant keep the car cold on stop start traffic.

But in terms of efficiency, isn't the fan of minimal use when travelling faster than 60km/h?
Not arguing that. Just you need to ensure that air goes through the radiator, not out under the car. When I had a 16" DC thermo, I could get the fan to switch on on a slight uphill on the highway on a 23 C day.

The engine had seriously overheated during a track day at Winton (25 C) - within 1 lap the temp gauge was off the scale. I replaced the factory fan, and left the tell-tale light in place - 4 laps of QR (30 C) and the tell-tale lit up on the last run into the finish line.

Figured my engine wasn't worth that much risk.

Also, what about all the FWD cars that run electric fans from factory?

Cheers

That's because the engine is parallel to the radiator - the front of the engine isn't facing the radiator for a mechanical fan to work!!
That's because the engine is parallel to the radiator - the front of the engine isn't facing the radiator for a mechanical fan to work!!

Sorry, I wasn't clear with that one...

what I was getting at was, if the rad fans are shrouded correctly, elect thermos are surely as effective as mech ones...?

I have used a single 16 inch davies craig fan on the GTR. Unfortunately they draw an enourmous amount of current so you must rig them up to a thermo switch otherwise you lose the power benifit if they are on all the time. They also work within the factory shroud and reduce rotational mass to boot.

So how much is it to have a new shroud made up for the twins.Or any of the thermo fans??

The car wont overheat.If anything the fans should be set up right in the first place.Like having a thermo switch kick the fans on at optimal temp.

Question!

How much leeway should be taken into account when trying to get the engine to stay at a set goal temp.Like when should they start/kick in to be able to hold 76deg/c?

I run twin thermo's on an SR20DE+T. Since my GTR died, due to heat, I have been worried about temp.

Even with a hi-comp engine, running boost, in a drift car, so has seen a bit of stick, the thermo's are amazing.

When having the car tuned, the tuner was amazed he could not get the car over 80degrees. Hot days are not a problem and even sitting in traffic, I rarely see 75.

Also, they help cool the engine AFTER I turn the car off which I like.

I'm a big fan.... kehehe, I'm funny...

thermo fans are by far a better way to go.....its just that 90% of the setups i have seen people seem to hook them up incorrectly (hotwiring them ect)generally they pull 10amps a peice and north south oem applications????at a split second thought ford falcons,commodores have had them for years.....if i had another 10 minutes think i could think of quite a few more id reckon

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