Thermo fans and engine temps

[ndgcpr]

I got my fan off a mate but it is a single probably 15inch fan which i think he said was off a berlina or something, It doesn't cover my whole radiator but it move a HUGE amount of air, like you can stick your hand on the front grill with the bonnet down and feel the suck or air through it. I find fans work much much better if the blades have a ring around them, if you know what i mean, the tips of the blades and attached to a ring to move air through it instead of it flying out the side.

Mine is a 1G-GTE but so it probably doesn't need alot of air but it works well.

[ProjectSleeper]

My set up consists of.

Twin DaviesCraig DCSL14's mounted on a custom aluminium shroud attached to an aluminium core factory sized radiator. I have a big 600x300x76 Intercooler, 300x200 Trans Cooler, Factory Air Con condensor all sitting in front of the Radiator which severly limits the flow of clean/cool air available to get top the radiator.

I am using the Autospeed / Jaycar Simple Voltage Switch to control the fans and so far the whole package is working brilliantly.

One of the best things is how quiet they are in comparison to the factory Hydraulic fan.






Another thing to be wary of...
Do you have an undertray fitted ?? - you may find it will improve flow if you have the tray fitted.

Also, as I posted in the other thread on ToyotaCressida.net..

The total area of the radiator core is approx 2,625 sq/cm
The total area of my fans on their own is approx 1,925 sq/cm
So, the fans on their own only cover about 73% of the radiators area.
But by using a purpose built shroud, I can draw air through almost all of the remaining 27%of the radiator area, so the whole system is more efficent, and the fans will not have to work as long, or as often to get the same result...

The 14" inch each flow about 400 Litres per second @ 40 pascals
The factory 45cm jobbie is good for about 850 Litres per second @ 40 Pascals. - but it is over a 400cm sq smaller area..

To give you an idea just how much air they displace - when standing at the back of the car, you can feel the rush of hot air underneath when they switch on..

[gianttomato]

I find it very difficult to tell which way the fan is blowing by just placing my hand in front, so I like to use a smoke trail (cigarette works fine if you know someone unfortunate enough to smoke).

I just use a piece of paper and see where it ends up.

[dori dori]

On my mega powah 7M Soarer i used two Davies Craig thermos - one 14inch the other 12inch. Because i'm a slacker i didn't make up a shroud and they worked perfectly.

Just my 5 cents

[TTMX83]

Shane - Do you still have the plastic under tray fitted?? The one under the sump? I think the hydrolic fan is the best bit of gear. Is there any way you can fit a couple of smaller electric fans in between the radiator and intercooler? Then still run the hydro as well. I can't remember how much room you have left there.

Also I'm trying to figure out if the tray/shield I have fitted to mine makes it better of worse. I guess if I had an electric fan it would help with the bonnet open as the air has to go through the radiator... Bonnet shut, it does nothing the bonnet doesn't do. I think it would help at the drags though, with the bonnet open, car off, electric fan running.

[3t-RA40]

I been doing a little reseach on this lately and the skew blade or S blade draw/push more air than straight blade. I was also going to go for 16" but in the skew blade configuration because of the air con. Also I know it sounds dum but check the wiring and/or the blade, wiring obvious, but sometimes the blades are reversable.

From PWR website - http://www.pwr.com.au/pwr/content/accessories_fans.htm
SPAL Thermo fan:

16” = 2720CFM (straight blade) = 3500CFM (skew blade)

13” = 1750CFM (straight blade)

12” = 2080CFM (straight blade) = 1750CFM (skew blade)

11” = 1370CFM (straight blade) = 1500CFM (skew blade)

10” = 1100CFM (straight blade) = 1150CFM (skew blade)

9” = 1060CFM (straight blade) = 1100CFM (skew blade)

DAVIS CRAIG Thermo fan:

16” = 2120CFM (straight blade)

14” = 1270CFM (straight blade)

12” = 1060CFM (straight blade)

10” = 847CFM (straight blade)

9” = 653CFM (straight blade)

[sideshow]

i would go back to hydro

i had a 10 and 11 in thermo and once the temps get over 95 theres no way to bring them down quick enough

i went to a custom aluminium radiator with a ultra slim 16 in thermo and it fixed nearly all my probs

i thought davis craig fans where good flow but these days i think they cant compete with brands from usa when it comes to airflow and size

anyway my alloy rad cools much better than the tripple core copper one i had

and on the highway at night it will run at 74 degrees

i have a trd racing thermostat that opens at 71 i can get them but they are not cheap

im goin to put vents at back of bonnet to get air out of enigne bay this should help more

[SL666]

even on 30deg days, i don't seem to get any overheating, with my tiny excel radiator, and pizzly thermo.. obscure

[ProjectSleeper]

I been doing a little reseach on this lately and the skew blade or S blade draw/push more air than straight blade. I was also going to go for 16" but in the skew blade configuration because of the air con. Also I know it sounds dum but check the wiring and/or the blade, wiring obvious, but sometimes the blades are reversable.

They fail to mention at what pressure those figures are..

When I spoke to one of the blokes at Davies Craig I explained the application and what I was after etc.. As he said to me - (and I hope I get the explanation right, I was never any good at Physics etc..)

- Always check the flow rates at about 40 to 50 pascals as a minimum as that is what most good condition average Radiators are rated at. Some fans might flow great numbers at zero pressure, but once they are loaded up, even slightly, they suffer greatly..

To give you an idea of how pressure affects the rating, take my 14's for example..



At 00 pascals - approx 500 Litres per Second
At 40 pascals - approx 395 Litres per Second
At 80 pascals - approx 320 Litres per Second
At 120 pascals - approx 225 Litres per Second

This is were the Hydraulic / Clutch fans work better ( when there is more pressure build up - ie, blocked radiator or restricted airflow) - they do not suffer at the same rate at electric fans.

[MR 1JZ]

All that said, no thermo will ever be as good as the hydraulic unit.
Maybe put that back on AND put a pusher on there for when the car is off?

best advice here...I would have killed for one of those hydro fans when I did my conversion as i have seen the amount of air they pull...fucking fantastic flow!

I just use a piece of paper and see where it ends up.

just dont use your hand...or this might happen to your finger:



that was 6 months later after it had "healed"

EDIT: Semi-better photo



notice the chunk of my pinkie missing

[Endless]

Gotta vouch for the stock hydro setup, would be extremely hard to match the flow that it's got, fucking unbeleivable ... i reckon Cruzida's idea is the go.

[Draven]

gotta agree with the boys - either go back to the hydraulic unit, or install some AU falcon thermos like I did (as long as you have a jigsaw and a file you'll be sweet)
The au falcon thermos have held my 1j rock solid on whatever the microtech tells it.

[sideshow]

another thing to watch out for is toyota temp gauges suk ass

when my temps used to get up over 115 on the diag scanner

the temp gauge only moved about 2 or 3 mm

so for it to read close to the red it prob would need to get over 130 degrees

so if u ever have temp probs or are just curious buy a decent gauge

the std gauges wont tell u much

[CrUZida]

You must have a shit guage then Sideshow.

My stock MX73 guage would read in the middle for about 75-95degC

It would start moving north at about 97/98deg, and by the time the Microtech read 100deg the guage was almost in the red.

[ProjectSleeper]

You must have a shit guage then Sideshow.

My stock MX73 guage would read in the middle for about 75-95degC

It would start moving north at about 97/98deg, and by the time the Microtech read 100deg the guage was almost in the red.

Yep, found a similar thing when setting up the controller on mine..

90-95 was about half and 100 was about 3/4 of the way up..
It also has to do with where you are measuring the two temps from..

My guage's sensor reads about 2cm before the ECU's sensor and comparing the resistance on the ECU's sensor to the temperature chart I was given by Toyota - there was stuff all difference