Thermo Fan Uses?

[osiris23]

Hey im looking at getting rid of the factory clutch fan on my 33 and upgrading to a pair of thermo fans. Just firstly interested in what size i should get? i was thinking get duel 14" fans and have them hooked up to ignition.

Anyway my second question i was just thinking is pretty stupid but anyway. Would a pair of thermos be any use on a FMIC. i would can see it most probably wouldnt be as its right in the front of the car always getting air through but what about on idle. would it make any different keeping air going through say when your at the lights or something? just a thought.

[dr00]

best to have them hooked up to a switch that comes on at a certain temp. i have mine set to come on at 83deg and turn off at 80 so they only come on if im sitting at traffic lights for a while or something.

thermos on a cooler would be kinda pointless... you need a cooler because turbos heat up the air when it is compressed. sitting at a set of lights theres no boost so no heating of the air.

[osiris23]

yer thought it would be pointless just i saw a 4wd TD and had a cooler with a thermo on it so just got me thinking.

[FATGTS-R]

I have an R31GTSR and it came factory fitted with a thermo fan bolted to the front of the front mounted cooler.

I also dont see how much effect it would have though.

[Psymon]

I guess it's only real benifit would be if the front mount was in a place where it was getting the best airflow. On most cars this shouldn't be a problem at all though!

[fresh]

being a 4WD there would be plenty of situations when the engine is flogging it tits off on full boost and the car is barely moving at all, low range can see a car doing 1.7 km/hr on the redline....hence zero airflow and max boost

[bbe]

whilst sideway ( driftn ) there is no frontal airflow hence the reason some choose to use thermo

i have thermo in 32 only 12 inch to ignition with no problems always stays at half temp ( dodgy factory gauge )

[osiris23]

so for my radiator would 2 12" thermos be perfectly fine or get larger ones. havent measured the radiator to see what size i can fit yet as it was pissing rain all day today.

[Crimpage]

Looking at the specs on the Davies Criag website. The 14" pumps 480L/s and the 16 pumps 1000L/s...

So, 2x14" Fans dont do the job of 1x 16".

However, the 2x14" would cover more space on the radiator, and may cool better for that reason...

[Abo Bob]

Many people recommend you keep the stock fan but if you must go thermo then get one 16" rather than 2 12's. I'm not sure 2 14's would fit anyway.

The only other reason I can think to have a thermo on your intercooler would be if it was a stocker and you used it to cool the thing down at the lights before you take off but after you just boosted. Not much use but that's all I can think of. There are plenty of better things to spend your time and money on.

[osiris23]

Thanks for your help guys.

Yer that was the thing i was thinking about with the thermo on the cooler say if you stopped at lights it would always still be putting air through the core.

Might look into 1 16" put it on one side of the radiator and possibly a smaller fan on the other half which would fit.

Although 1 16" thermo would have better cooling capabilities then the factory clutch fan wouldnt it?

And also why many people say not to use a thermo? I thought it was a bit less strain on the motor and would provide better cooling?

[rb20inside]

mate uses 2x12in fans on his rb25, works fine. using a thermo switch off the ignition so the fans only come on for bout 8 secs at idle.

i'm using 1x10in and 1x12in on my rb20 (in a 180sx) running straight off ignition and it stays just under halfway on the dodgy stock temp gauge.

another mate has 1x16in davies craig fan. it sucks alot of air and at idle only stays on for a few seconds. only thing is it uses so much power the motor struggles to idle. he has it running straight off a thermo switch so it has the added wank factor of staying on after the car is turned off.

in my opinion twin thermos are more efficient than one due to the greater surface area

what ppl say bout a standard fan bein better than thermos is in most cases refered to as without a shroud where the heatsoak of the engine negates the effect from the bigger fans

Edited May 8, 2006 by rb20inside

[R33A31]

I plan tu use 2x12" to my rb25det. 1 direct to ignition switch & another 1 to thermo switch with individual relay...any comments on this method?

[BHDave]

I run 2 14's. one replaces the factory ac fan and the other is on the back on the opposite side of the core.

2 12's just didn't cut it in my car (r32 with rb25det)

[grim32]

I run 2 14s on my rb20 wired via a davies craig temp switch to turn them on and off, this gets power from the ignition so when the car is turned off the fans shut off too.

[rice_me_up]

I plan tu use 2x12" to my rb25det. 1 direct to ignition switch & another 1 to thermo switch with individual relay...any comments on this method?

so when you have 1 to the ignition switch you mean it will come on as soon as you start the car????

if thats the case then i wouldnt do it. The car needs to reach a certain temperature before it runs safest. having a fan run as soon as it starts (on a cold start) would slow this process down. i reckon just have them both to the thermo switch would be best.

[Abo Bob]

Also there's no point in running the fan when the engine is off unless you also have an electric water pump running to circulate the water otherwise you are just cooling the radiator and nothing else.

It has been proven and I believe stated earlier in this thread that 2x12's DO NOT pull as much air as one 16".

[R33A31]

so when you have 1 to the ignition switch you mean it will come on as soon as you start the car????

if thats the case then i wouldnt do it. The car needs to reach a certain temperature before it runs safest. having a fan run as soon as it starts (on a cold start) would slow this process down. i reckon just have them both to the thermo switch would be best.

I agree with u rice_me_up.

Engine must run with certain temp. so, wich one more efficient 2x14" or 1x16" ?

[Abo Bob]

Ok then:

........................................2x14"........1x16"........Which wins?

Weight...............................3kg...........3kg..........Nothing in it

Amps needed......................22.............19...........16"

Litres of air moved while

sitting still..........................1000.........1000..........Nothing in it

Litres of air moved at

40P of inlet pressure............780...........850...........16"

What I don't know is why they flow less once you are moving, perhaps it's a relative thing. Ie; they don't count the air the would have gone through anyway.

I think the decisive factor here is power consumption. Use more power, put more load on the engine, robs it of power and uses more fuel.

[Bass Junky]

I have been toying with this idea for quite some time.

Is there a big enough benifit of changing to Thermo fans?

Does anybody have the fans hooked up so that in normal driving they don't come on at all until about 85 degrees?

Is anybodies cooling system efficient enough to control temperatures without a constantly running fan?

My old VN Commodore V6 never had a clutch fan, and it did perfectly fine......

BASS OUT