Atom cooling

[John Scherrer]

The charge cooler or intercooler only cools the intake air on its way to the inlet manifold, so it won't affect the water temperature at all.

This also applies to the Atom 4 concerns that some have commented on regarding the lack of fan on the '4' intercooler. Some had said that when the car was stationary, there would be a heat soak problem .. When stationary, there is no need to cool the intake charge ..

[Toilet Duck]

The charge cooler or intercooler only cools the intake air on its way to the inlet manifold, so it won't affect the water temperature at all.

I think you're incorrect there. The supercharger has the negative effect of heating up the air going into the engine, Jackson Racing chargers are known to generate a lot of heat. Indeed, if you dont fit a chargecooler when upping the boost (e.g. on a 3.5R) you risk detonation due to the increase in inlet temps and blowing the engine up! This heat won't disappear into the ether, a considerable amount will be "absorbed" into the engine and then into the oil and water etc. A chargecooler significantly reduces the inlet temps by transferring that heat into the water within the chargecooler circuit and looses it via the heat exchanger. This will reduce the loading on the cars engine cooling circuit but by how much I have no idea.

[John Scherrer]

I agree that compressing air causes an increase in temperature (as in the cycle pump getting hot when you pump the tyres) - I'm guessing it's nothing like as much as the heat from combustion and presumably a lot less with a supercharger than a turbocharger which gets the added heat from the exhaust gases driving the turbine.

Hopefully, if the intake temperature reaches a certain threshold deemed to be dangerous, the ECU will respond and retard the ignition timing to prevent detonation (and also reduce the power output)

[Osky]

I know this is an old thread, but how do these extra horizontal radiators mount to the Atom? I see they have horizontal "flaps" that I assume must be something to do with the mounting, but there aren't any holes or fixing points in them? Any owners with one fitted mind sharing a pic of the horizontal radiator fitted please?

P.S. import_trung, that is a quality bit of fabrication! Looks twice as thick as the pic of the Factory option!

Hi!
I have installed the "hot country radiator" "in aftermarket". I found 2 possibilities to fix it: with rivets or with metal clamps (I hope the word is correct, but you can see the pictures). I have choose the second solution.
Here some pictures about the installation (not easy ... ).
I have the standard radiator in the front, with the standard fan.
With the second radiator, the situation is better, but in very hot day (more then 35°C) and with a car in the front, the water temperature arrive at 100 (with both fan running and the light on). If I turn the light off, the temperature drops to 97°C immediately ...

[Toilet Duck]

Hi Osky,

Many thanks for posting up those pics! The metal clamp fixings look good as you don't have to drill/modify the chassis etc.

Do you mind clarifying this bit please:

With the second radiator, the situation is better, but in very hot day (more then 35°C) and with a car in the front, the water temperature arrive at 100 (with both fan running and the light on). If I turn the light off, the temperature drops to 97°C immediately ...

Is this on track days or just driving on the road? Also, what "light" do you mean? I can't think of a light you can turn off that would effect temperature??

Cheers

[autobackup]

Osky

Have you fitted a fan to the bottom horizontal radiator?

As it is mounted 'out' of the airflow and I can't see any forced cooling (fan) fitted to it in your photos, I would imagine that the cooling effect of the secondary horizontally mounted radiator is rather minimal?

Living in Cyprus with temperatures regularly in the late 30's (39C yesterday!) my Atom 3.5R's coolant temperature generally runs at 85-89C - in trafffic it creeps up to 94C (I've never seen it higher) at which point the fan cuts in - usually the fan drops the coolant temperature back below 90C after only about a minute or so's running!

My impression is that after the recent upgrade the coolant fan is running about 60%-70% less than it did last year when I had the standard fan and radiator fitted.

After a month's hot weather use in Cyprus I am now definitely of the opinion that that the recommendation by Ariel of retrofitting the larger Atom V8 radiator and variable speed larger fan is by far by far the best solution and, from your comments, would seem to be much better solution than the hot weather dual radiator option - especially if you are getting coolant temperatures of 100C with the outside air temperature at only 35C?

[Toilet Duck]

Osky

Have you fitted a fan to the bottom horizontal radiator?

autobackup,

Osky has fitted a fan, it's shown fitted in two out of the three pics he posted.

Googling the part number shown on the fan shows it's this 10" SPAL "puller" fan so it pulls air from underneath the car through the radiator core.

Cheers

[John Scherrer]

Also, what "light" do you mean? I can't think of a light you can turn off that would effect temperature??

This is well documented on the forum by some, when you turn on the lights, the indicated water temperature on the dash increases.
Thought to be an electrical grounding issue somewhere ..

[Osky]

Also, what "light" do you mean? I can't think of a light you can turn off that would effect temperature??

This is well documented on the forum by some, when you turn on the lights, the indicated water temperature on the dash increases.
Thought to be an electrical grounding issue somewhere ..

Yes, I mean exactly this!
When the Atom has some load (the light, the fans, etc), the displayed temperature is higher then without load.
And I suspect it depend by the sensor and the ground ... because the sensor has only 1 wire.
On the road i ususlly drive with the light on, so i know the displayed temeprature is +3°C more.
My fans (now I have 2 fans, one in the front of the standard radiatore and the other in the top of the second radiator) start at about 96°C (displayed value). When all 2 fans start, the displayed temperature increse up to 100-101°C, then it starts to decrease until about 92-90°C when the fans stop.
I'm not sure about the outside temperature when I run on the Atom (it doesn't have any temperature indicator ), but in these days the outside temperature is about 35-38°C in the middle of the day. On 31 August, if the wheater reamins the same, we can hae a comparison with the Atom guys that will come in Italy.

[Osky]

Osky

Have you fitted a fan to the bottom horizontal radiator?

autobackup,

Osky has fitted a fan, it's shown fitted in two out of the three pics he posted.

Googling the part number shown on the fan shows it's this 10" SPAL "puller" fan so it pulls air from underneath the car through the radiator core.

Cheers

Yes, under suggestion of the Ariel, the fun "sucks the air from the floor and push it into the sky"

[Osky]

Hi Osky,

Many thanks for posting up those pics! The metal clamp fixings look good as you don't have to drill/modify the chassis etc.

Do you mind clarifying this bit please:

With the second radiator, the situation is better, but in very hot day (more then 35°C) and with a car in the front, the water temperature arrive at 100 (with both fan running and the light on). If I turn the light off, the temperature drops to 97°C immediately ...

Is this on track days or just driving on the road? Also, what "light" do you mean? I can't think of a light you can turn off that would effect temperature??

Cheers

Note: to fix with radiator with the metal clamps, you need to driil the external "wings" of the radiator. Maybe the easy job to do during it installation!
Note 2: I have had to add a second relay with its fuse and wiring from the battery and the primary fan (I have decided to run the second fun in parallel to the first one, but with power direclty from the battery with a relay and fuse).

[Osky]

Also, what "light" do you mean? I can't think of a light you can turn off that would effect temperature??

This is well documented on the forum by some, when you turn on the lights, the indicated water temperature on the dash increases.
Thought to be an electrical grounding issue somewhere ..

About this point Thought to be an electrical grounding issue somewhere .. Do you have the grounding points to checks, please?

[John Scherrer]

No sorry, the US owners discussed this quite a long time ago (Terry Kennedy), but I don't have any direct experience myself.

A bit about this here :-

viewtopic.php?f=4&t=9918&p=197819&hilit ... re#p197819