Thermo Fans

[dirtythirty3]

Looking to put thermo fans on rb25.

Instead of having it come on at a certain temp can i just hook it to The battery and in cabin switch?

Cheers

[kitto]

You can, but why the hell do you want to put a thermo fan in? Stock rb25 clutch fan WITH the shroud shits over any thermo fan. If your having over heating issues, your problem lies elsewhere.

Stock radiators are fine aswell.

[dirtythirty3]

Twin thermofans from ef/el

I know that in the ford its a good upgrade

Already got some huge radiator made up. Just thought it would be good for revs and get rid of that annoying air noise.

[bubba]

I've kept the mechanical fan but put two thermos on the front of the radiator. Ran a +12v feed to a pair of switches on the dash which give a signal to the relays to power the fans.

[dirtythirty3]

Just figured if a ford turbo uses thermos surley it would be more than fine for an rb.

I guess il give it ago soon.

One thing, my cars temp stays just under half after 15-20mins of driving but then even after a few hours of hills driving wont budge past just under half...

Cheers though guys

[GTS-t VSPEC]

I have twin thermos on my radiator, works perfectly fine, and that's after 10 hard laps at Wanneroo

[dirtythirty3]

^ ohh much diffrence rev wise?

[sh@un]

I have twin thermos on my radiator, works perfectly fine, and that's after 10 hard laps at Wanneroo

did you notice any improvement in throttle response/engine revability after removing the viscous thermatic fan?

[bubba]

Just figured if a ford turbo uses thermos surley it would be more than fine for an rb.

I guess il give it ago soon.

One thing, my cars temp stays just under half after 15-20mins of driving but then even after a few hours of hills driving wont budge past just under half...

Cheers though guys

Don't rely on the stock temp gauge, I've found that it doesn't move off the lowest point until about 60deg and it won't perceptively move off the half way point until temps reach about 100deg.

[kitto]

Sometimes a huge radiator can make you worse off. As the coolant flows through the rad too fast and doesnt have enough time to cool down.

Unfortunately ill have to use thermo fans in my R31 as the clutch fan will hit the rb26's harmonic balancer using an R31 viscous clutch. And using an rb26 clutch pushes tge fan too close to the radiator.

Id prefer to use a clutch fan, even when my car is for circuit only.

They just work so damn well.

[R31Nismoid]

I used a stock clutch fan on my GTR - driving around town temps are in the mid-high 60s on a 20 degree day.

Going flat out @ Track Battle doing 5 laps (58-60) sec lap i think temps got to around 90 and the ambient on Sunday was 20-22. Thats with 350rwkw/19psi as well.

Thermos might indeed be able to keep up - they might not, that's something i wont be toying with though.

Sometimes a huge radiator can make you worse off. As the coolant flows through the rad too fast and doesnt have enough time to cool down.

Mine is a triple pass - so whilst big, avoids that issue.

It's not a PWR item, but i know PWR do them. There are other places as well that are doing them now also (that bolt into a skyline etc)

Unfortunately ill have to use thermo fans in my R31 as the clutch fan will hit the rb26's harmonic balancer using an R31 viscous clutch. And using an rb26 clutch pushes tge fan too close to the radiator.

My HR31 with a RB26 uses a RB clutch fan. Also has a Ally Radiator thats larger than factory by a fair margin.

I think we used a GTR fan and just modded the HR31 shroud to suit.

[wolverine]

I have twin thermos on my radiator, works perfectly fine, and that's after 10 hard laps at Wanneroo

Forgive my ignorance but wouldn't thermo fans suffer more issues in stop start traffic on a hot day.

On a track with all the extra airflow, fans (viscous or thermo) are not likely to be pulling/pushing much air anyway.

[gotRICE?]

I used a stock clutch fan on my GTR - driving around town temps are in the mid-high 60s on a 20 degree day.

Going flat out @ Track Battle doing 5 laps (58-60) sec lap i think temps got to around 90 and the ambient on Sunday was 20-22. Thats with 350rwkw/19psi as well.

Thermos might indeed be able to keep up - they might not, that's something i wont be toying with though.

Mine is a triple pass - so whilst big, avoids that issue.

It's not a PWR item, but i know PWR do them. There are other places as well that are doing them now also (that bolt into a skyline etc)

My HR31 with a RB26 uses a RB clutch fan. Also has a Ally Radiator thats larger than factory by a fair margin.

I think we used a GTR fan and just modded the HR31 shroud to suit.

You seem to quote your cars running seriously low temps all the time. I know the R31 runs cooler for everyone, but shit, in a stock RB25 VCT doesnt even work till 70C.

Why do yours run so cold? Do you run low temp thermostats? Or any thermostat at all?

Mine sits at 84-85C day in day out regardless of the temps outside.

[R31Nismoid]

Yeah i know! It's not a concious choice, just how they are.

Not sure what thermostat is in the GTR, I've not had that out, so i cannot comment other than i know it's got a triple pass radiator. If it ever comes out i'll have a looksee.

The HR31 has a factory RB26 thermostat, know that for sure. It runs between 69-72 degrees on a 20 degree day.

We actually tried another new thermostat in it just to be certain it wasn't stuffed. The motor also sits much lower in a HR31 than it does in a GTR, perhaps that is something to do with it all?

Don't have VCT so i guess it aint a problem

Temps might get up higher in peak hour stop/start type of thing. I rarely drive in peak hour that often (i walk to/from work daily).

[gotRICE?]

haha yeah i know you dont have VCT (GTRs should though )

Just seems like its far to low even for a 33. Meh. Spose if the tunes correct for it its fine.

Edited September 29, 2011 by gotRICE?

[blind_elk]

I do wish people would do some research into why thermo fans are used in automotive applications.

The main reason is to remove some load from the engine. BUT, if you simply wire the thermos up so they are on all the time, then all you have done is move the load from the water pump (viscous fan location) to the alternator (additional electricity needs to be generated to drive the fan(s)).

It is also not necessary to set the thermostat for the fans to around normal operating / thermostatted temperature. In general, the movement of the car forces sufficient air through the radiator at normal road speeds to keep the temperature of the coolant under control. Only in stop / start type situations does the coolant temperature rise above thermostatted temp, but there is absolutely no danger in that under those conditions. Once the car gets moving again, the coolant will return to normal operation temperature. So, it is not impractical to set the thermo fan switch point to 90 or even higher.

In a Skyline, with the A/C radiator and probably a FMIC, it is not possible to mount a thermo fan in the most efficient "push" position, and you need to mount it as a less efficient "pull" setup.

All that being said, my experience is that the design of the front of a Skyline does not allow air to be forced through the radiator while the car is in motion. I have had much better temperature control when the factory viscous fan is fitted, because it creates a permanent air flow through the radiator.

[dirtythirty3]

Sorry guys im

On the iphone i have no proper internet and researching on google takes way to long.

I figured a constant load on the alternator is better then the increasing load from the clutch fan as you increase revs.

Thanks for the insight on it all

[woolls]

I am running a twin pass PWR Rad with a 16" Spal Fan. Its controlled through the ECU (Haltech).

It comes on at 90 and goes off at 95. This is on a circuit r33 gtst with 420 rwkw and works great. The only time fan comes on is when lined up on dummy grid and on cool down lap.

[JonnoHR31]

You seem to quote your cars running seriously low temps all the time. I know the R31 runs cooler for everyone, but shit, in a stock RB25 VCT doesnt even work till 70C.

myne does the same, wont budge from 69 on a cool night/cold day no matter how hard you drive it. also has a genuine thermostat in perfect working order.

OP, for a street car the standard clutch fan is much better than thermos, leave it as is and spend the money on other mods. if you have overheating issues, sort them out, thermos wont help at all.

Edited September 29, 2011 by JonnoHR31

[wlspn]

Have a 16" Davies Craig on my RB25 R32, controlled by a Haltech ECU with an override switch in the car.

Never had a problem with overheating, be it on the dyno, heavy traffic, etc temp is very stable.