Replacing The Radiator Fan With Electric Fans. Performance Benifit?

[rev210]

ran 2x12" DCSL12 fans, 1x Stock 12" A/C Condenser fan

No shroud, as there was no room (RB in a 180SX)

Thermo switch located at the bottom of the radiator tank, with thermo switch swapped from the stock 90 degree one to a mitsubishi lancer one which activates at 82 degrees

Wired all 3 fans to separate relays, straight to battery, thermo switch went to ignition power, then to the trigger on the 3 relays, diode was used to switch only 1 fan (the A/C condenser fan) when A/C was on and another diode was used to stop the A/C compressor kicking in when the thermos were on.

I had no choice of what to use, was either thermos or nothing, and there was no room for a shroud.

But saying all of that, my current car has the stock clutch fan & shroud and I can tell you I won't be changing it at all.

No wonder you had issues dude.

On top of those 12 inch fans being crap and they flow less than lots of even smaller fan options. And no shroud throws it all away.

The single 16 inch davies craig outflows that combo and will fit inside the factory shroud with minimal cutting. You can get much better and slimmer fans than either of these though. so I would leave that brand alone now.

[TiTAN]

i use 2x 12" thermo fans attached directly to the radiator and on from the moment the engine is started. unless you are thrashing the shit out of it on a hot day it never gets above 90 using the stock radiator.

[SkyHi_33]

have any of the people that have had over heating problems been running a shrowd? I want to piss my clutch fan off just cause it's a pain to remove if i need to work on it.

Those AU ones look pretty good, is the raidiator in a AU about the same dimentions as a skyline?

The BA fans I got are pretty much the exact size as my r33 gtst radiator... not sure on AU ones or the size of the GTR radiator tho.

[Angus Smart]

Ford BA BF - 76cm x 46cm x 11cm

is what i could find on the Ford twins,

i was considering going this option but have since bought a large 16inch fan and will build a nice alloy duct and shroud for the radiator.

no a/c and no clutch fan shall be nice

[bubba]

Here's a question.. I am planning to run my thermos on the front of the radiator (where the aircon condenser normally is), with the structural supports around there it looks pretty easy to make a shroud for the fans..

The only thing that I'm concerned about is stemming the airflow INTO the radiator when the fans aren't running.. would is be a restriction? or would I also need to put some ducts/guides in place that reduce perfectly down to the fan intakes?

[Angus Smart]

i'm thinking (probably not the best thing) that because its in front you dont need to so much do this, perhaps a duct the size of the radiator to guide air into the radiator and thru the fan would be ideal..

but blocking off the front of the radiator with a shroud similar to ones on the back doesnt sound too good

[bubba]

i'm thinking (probably not the best thing) that because its in front you dont need to so much do this, perhaps a duct the size of the radiator to guide air into the radiator and thru the fan would be ideal..

but blocking off the front of the radiator with a shroud similar to ones on the back doesnt sound too good

Yeah that was my thinking too. I'll be making a splitter/guide to go at the top and will do something to give it maybe 50mm of duct (from face of radiator to face of supports). Also thinking of running a sheet of ally from the top of the intercooler to the splitter/guide.

Once I get a new front bar (N1) I'll flash the intercooler to the front bar aswell.

[SkyHi_33]

if you have the fans setup so they run on really slow speed the whole time and speed up only when the temps pick up, then i don't really see a problem there...

otherwise id be looking in to opening the front up a bit more or putting ducts in, especially if youre running a decent sized fmic.

[bubba]

if you have the fans setup so they run on really slow speed the whole time and speed up only when the temps pick up, then i don't really see a problem there...

otherwise id be looking in to opening the front up a bit more or putting ducts in, especially if youre running a decent sized fmic.

Talking about my setup?

[Dose Pipe Sutututu]

on the same topic.. how did you R33 boys remove your radiator & shroud without unbolting the A/C line to the condensor?

I had to illegally degas my A/C to remove my A/C to replace all the belts on my car.

[blind_elk]

I honestly don't think you understand at all the reasoning behind thermo fans.

Air flowing through the radiator due to the forward motion of the car is ordinarily sufficient to maintain the temperature of the coolant to the thermostatted temperature; fan or no fan. Thus, in the majority of the engine's "on" time, any form of fan is superfluous. It is only during times when the motion of the car is insufficient to induce adequate airflow through the radiator that supplemenatry air flow, by means of some sort of fan, might be required. It is only really required when the temperature of the coolant (regardless of where it is measured) is more than, say, 10 C above the thermostatted temperature.

Had the fans been maintaining say 60-70 deg C in the RADIATOR then there would be a cool water reserve to enter the engine when the thermostat opened up wide and a steady temperature is easier to regulate

You completely neglect the role of the water pump in continually circulating coolant (once the thermostat opens) from the radiator into the engine block and head, where it removes excess heat from the metal of the engine. If the fans are able to maintain 60-70 C (in an engine thermostatted to operate, like the RB-series, at around 89C), then the thermostat will be closed, and no coolant will be able to enter the engine block and head.

So elec fan sensors need to switch the fans on BEFORE the temperature of the water in the radiator reaches that of the water thermostats rating .

Frankly, I doubt you will be able to name a single manufacturer who fits thermo fans as standard, and sets them to operate permanently. They only ever come on when the coolant temperature gets to a certain level above the thermostat temperature.

[lachlanw]

i have a book here abou teverything turbo and it recons that pulling fans are better than push fans . and says it has even heard of a 1000 cfm pull setup out cooling a 1500 cfm push setup

[bubba]

Does it say anything about push fans and a pulling engine fan?

[noisia]

being in the refrigeration aircon industry i've noticed that 99% of condensor/outdoor units are induced fans (pull). the only forced fan (push) i have come across was a unit a couple of weeks ago.

which goes to show that induced must be the more efficent than forced, especially when heat rejection is so crucial for proper operation.

[noone]

Brought a set of I am pretty sure EL falcon twin thermos fit the radiator perfectly on my 32GTR but no way known would they fit in the engine bay without major butchering

from memory all the power steering lines were in the way I believe these are almost identical to the AU ones

They may fit a GTST or whatever but not a GTR

removal of they previous owner installed thermos and replacement of the stock clutch fan and shroud was one of the best things I did to my car

even on the track no overheating dramas and didnt notice any real change in response!!

[CrimsonLey]

Not quite done reading so I apologize if my question was answered already:

What is the best thermo fan configuration (I realize that proper shrouds are very import)?

I removed the clutch fan off my RB26. Currently, I only have a puller that activates when the ignition is on. It's wired from the condenser (overheat fan). Hence, the condenser fan doesn't work at all.

I'm thinking about having my Haltech control two fans: 1 puller and 1 pusher. Is that best best thermo fan combo I can do?

[R32 TT]

That works for me. SPAL 16" that comes on above 87 degrees and goes off when back under 85 degrees.

The front air con blower fan comes on at 92 degrees and also goes off once below 85 degrees. This means if the car has got hot then both fans kick in until it's back down again.

On top of that it's speed related. Both fans, regardless of temp go off once above 60 km/ hr.

And each will come back on (depending on temp) once car is going slower than 40km/hr.

Works well for track since as you slow down back into the pits both will come on a do a fast cool down..

[CrimsonLey]

That works for me. SPAL 16" that comes on above 87 degrees and goes off when back under 85 degrees.

The front air con blower fan comes on at 92 degrees and also goes off once below 85 degrees. This means if the car has got hot then both fans kick in until it's back down again.

On top of that it's speed related. Both fans, regardless of temp go off once above 60 km/ hr.

And each will come back on (depending on temp) once car is going slower than 40km/hr.

Works well for track since as you slow down back into the pits both will come on a do a fast cool down..

Perfect reply, thanks. I didn't consider having the fans dependent on the speed as well. Are you saying that the car automatically turns off and on the fans via it's speed sensor? I think my current configuration (from the previous owner) has the puller fan - which replaced the clutch fan and is behind the radiator - on ALL the time. It never turns off.

[Bond]

on the same topic.. how did you R33 boys remove your radiator & shroud without unbolting the A/C line to the condensor?<br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); "><br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); ">I had to illegally degas my A/C to remove my A/C to replace all the belts on my car.

Very easily.....not in the way at all. You must have missed something or it was bolted up funny

On top of that it's speed related. Both fans, regardless of temp go off once above 60 km/ hr.<br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); ">And each will come back on (depending on temp) once car is going slower than 40km/hr.<br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); ">Works well for track since as you slow down back into the pits both will come on a do a fast cool down.

I don't see the point in this set up. Why not leave it just temp related. If you have enough airflow it will be cool enough and the fans wont come on anyway. How about if your tailing a car above 60 and getting no airflow....it will just overheat

[CrimsonLey]

I concur. The fans really need to be dependant on the water temperature. I'm going to control them via my Haltech. My only concern its that my fans will turn off when the Haltech turns off.