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Question about everyone\'s radiators...

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pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#475171
For all those who have radiators not mounted directly behind a grill or in a bullbar, is your radiator mounted in a completely sealed box?

The idea being that air can only exit the box through the radiator. I'm particularly interested in people with rad's mounted in the spare wheel well or similar.

I'm thinking of sealing my radiator in, but I want to see what other have done.

Also, how big is the vent that scoops air into the box?

BTW, for all those running subies, what are your usual operating temp for traffic and the freeway, say 100km/h?
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

MickH Hairy Gutted Sloth

3,389 posts · joined Sep 2003 ·

#475186
My buggy sits on about 80/85 maximum on the highway on 120/140kmh with NO fan comming on.130kmh for half an hour in 3rd gear got me to 85 degrees🥷.Around town is about 90ish and the fan cycles.But my radiator is at the FRONT....🤓:beer
tssnq.com.au

MickH Hairy Gutted Sloth

3,389 posts · joined Sep 2003 ·

#475187
Mick H wrote:My buggy sits on about 80/85 maximum on the highway on 120/140kmh with NO fan comming on.130kmh for half an hour in 3rd gear got me to 85 degrees🥷.Around town is about 90ish and the fan cycles.But my radiator is at the FRONT....🤓:beer

That was also in the middle of summer up here!!!
tssnq.com.au

ricola Wolfsburg Wizard

437 posts · joined Feb 2003 ·

#475230
Mick H wrote:My buggy sits on about 80/85 maximum on the highway on 120/140kmh with NO fan comming on.130kmh for half an hour in 3rd gear got me to 85 degrees🥷.Around town is about 90ish and the fan cycles.But my radiator is at the FRONT
that sounds right to me, it should never be higher moving than stationary, that means your cooling ability is being limited by the radiator installation and not the thermostat which is the way it should be..

Rich
http://www.ricola.co.uk

GeorgeL Officially Full-On Dubber

231 posts · joined Feb 2006 ·

#475371
pete wood wrote:should radiator air boxes be of a particular volume ratio or something?
The really important thing is that you need to pick up high speed airflow and slow it down at the inlet of the radiator, raising its pressure. The outlet duct needs to exit to high speed airflow, which will have low pressure.

You don't want to go to all the work of doing that and leave gaps around the radiator! Gaps are particularly bad when airflow is low and you need a fan assist, as they allow hot air to recirculate.

George

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#483021
does anyone know what temp the fans are sposed to come on using the factory ECU?

anyone feeling really keen, does you know what temp the fans are spose to go OFF using the factory ECU?

also, what side of the radiator do you control the fans from? the hot side or the cold side?

I'm having a scathingly brilliant idea about fan controls based on the temp of the cold side of the rad and am thinking of trying something...


[ Edited on 1-5-2006 by pete wood ]
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

2443TT Fahrvergnugen

962 posts · joined Dec 2002 ·

#483090
My opinion... mount your thermal fan on the back of the radiator. This helps with the pressure drop as per what GeorgeL was saying. Ducting in the entire back of the radiator so that the fan can pull thru the entire area is also a great help to the efficency of the core.

Then the next mose important thing is getting that hot air away from the rest core. The moment it starts re-circulating hot air thru the radiator you can forget about any kind of cooling efficency.

I had a hot air recirculation issue when I used to have a 12x12x1.5 oil cooler up under my parcel shelf. Later to resolve the issue and wheel hop, i installed a traction brace and changed to twin front mounted oil coolers. Each cooler is mounted in front of the front wheels on a steel brace system that links onto the sway bar mounts on the front beam and also the hole at each end of the bumper bar that used to be used to connect the over rider bar to the bumper. The frame work is rigid enough to use to jack the car up so the oil coolers are well protected. There is an 8" thermo fan mounted on each oil cooler and shrouded in.

When driving in traffic the fans cycle in and out, and on the open road they turn off completely. The oil temp will regulate to a comfortable 150-160 degrees. The system would not work if it was re-circulating hot air all the time.

GeorgeL Officially Full-On Dubber

231 posts · joined Feb 2006 ·

#483112
iswinkels wrote:My opinion... mount your thermal fan on the back of the radiator. This helps with the pressure drop as per what GeorgeL was saying. Ducting in the entire back of the radiator so that the fan can pull thru the entire area is also a great help to the efficency of the core.
I agree, but remember that a few radiator fans are designed to push air through the radiator. I'm looking to use a pair of these because I want to mount my radiator horizontally under the frame rails and blow air downward through it. No sense reducing my ground clearance more!

Here's one I'm considering:



http://www.flex-a-lite.com/auto/html/low-profile-electric.html

I agree wholeheartedly with the thoughts about recirculation. I saw a EA81 installation in a singlecab that the owner was having a heck of a time getting to cool properly. He had a massive 3-core radiator mounted to the rear of the engine bay, but had nothing to direct the air. It was no wonder that the air just went round and round while his engine baked.

George

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#483119
you be pleased to see then that this my current setup...

The ducting is also being sealed completely soon, although, just by boxing in most of it, so only fresh air gets in, seems to help a lot already.

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"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

richbaker78 Casual Dubber

38 posts · joined Oct 2005 ·

#483471
GeorgeL - im interested in what you say about boxing in blowing fans too. With my design i also intend to blow the air out through the bottom of the rad.

My design mounts the rad up between the chassis rails with a sealed box above it - this sealed box is fed air rammed in and ducted from the front. If i put the fans on top of the rad with no shroud I presume the box which is airtight will perform the same function?

as regards slowing the air and raising pressure at the rad entrance I was thinking of creating a secondary duct feeding air in at high pressure into the main duct. The main duct rns from the front panel (its a van BTW) acroos the floor and drops down through the gap between the front seats - if I feed another duct into this at about 60 degree angle just before it goes into the plenum chamber above the rad would this cause the air in the main duct to slow and increase pressure? or would the plenum/airtight box itself achieve this result anyway - in which case should I feed the additional airflow direct to the box?

I hope that makes sense!!

GeorgeL Officially Full-On Dubber

231 posts · joined Feb 2006 ·

#483506
richbaker78 wrote:GeorgeL - im interested in what you say about boxing in blowing fans too. With my design i also intend to blow the air out through the bottom of the rad.

My design mounts the rad up between the chassis rails with a sealed box above it - this sealed box is fed air rammed in and ducted from the front. If i put the fans on top of the rad with no shroud I presume the box which is airtight will perform the same function?

as regards slowing the air and raising pressure at the rad entrance I was thinking of creating a secondary duct feeding air in at high pressure into the main duct. The main duct rns from the front panel (its a van BTW) acroos the floor and drops down through the gap between the front seats - if I feed another duct into this at about 60 degree angle just before it goes into the plenum chamber above the rad would this cause the air in the main duct to slow and increase pressure? or would the plenum/airtight box itself achieve this result anyway - in which case should I feed the additional airflow direct to the box?

I hope that makes sense!!
Either way, you will have to shroud the fans. If you don't, air can be drawn in through the radiator in the gaps around the fans and then pushed back through the radiator, picking up heat both ways. Not good.

I think that your setup is good without additional ducting. You've got the best possible air source (front panel) and all you have to do is duct it into a plenum and feed it through the radiator to a low pressure area under the car.

George

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#484094
just took my car out for it's first spin with most of the ducting on sealed in on the freeway.

sat on 60mph and the temp did not get above 80degC. 🙂

The fan's didn't come on at all on the freeway either. I'll be doing some more testing soon.



[ Edited on 4-5-2006 by pete wood ]
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/