Water temperature

[abcoro]

Hello. I received my new Atom 4 recently and just did a trackday with it here at Mettet in Belgium, past wednesday. It's the standard 320hp. In the morning all was fine and running great...obviously because of 3 reasons...not as warm as it was in the afternoon, first time ever I drove an Atom and...I was new to the circuit too.

In the afternoon, outside temp in the sun was around 34°C, so pretty hot for here in Belgium. I could do 3 laps at max before water temp reached 103 to 104°C and the red light for the water temp went on...and the engine went in "safe mode". Not sure "safe mode" is the right description but you could clearly feel that a lot of power was missing...

So upgrade with the cooling package is a must, not for driving on the road...but when you plan to drive on trackdays...it's a no brainer.

Best regards,
Abel.

[JT1020]

I driven 350 miles and seen water temp range between 88 and 93 degrees. (2018 AA3.5 K20)

[salvechris]

Even with the "big hot summer" package on the 4.......on the racetrack and over 25 degrees you only got a couple of laps before you must cool down a lap or 2.
That really sucks.

[alanoo]

On my Atom 2 I have (I think) a sensor on top of the water outlet and one inline on the hose that heads from it to the rad.

Arrows on pic - please excuse the condition of the engine it was pre the xmas refurb

Upping this, as said on next post, on earlier Hondas the fan seems to be controlled by a simple thermocontact (down left on your pic). Upper on the pic is the dash temp sensor. Honda sensor is directly on the cylinder head, below the Vtec sensors.

SAM_0132.jpg (155.75 KiB) Viewed 1255 times

Question is, anyone did the mod to control the fan directly from the ECU ?
Pretty sure it's possible as it seems the OE Honda wiring loom still have some unused stuff that seems to correspond to fan control on some PRB pinouts I found

WhatsApp Image 2022-06-26 at 19.37.38.jpeg (123.61 KiB) Viewed 1255 times

[speedmachine]

Even with the "big hot summer" package on the 4.......on the racetrack and over 25 degrees you only got a couple of laps before you must cool down a lap or 2.
That really sucks.

Does it go into limpmode, do you miss boost or is it just warning lights?

[salvechris]

you loose clearly noticeable power. It is around 103 degree water temp and above. I think Simon did some data records on that a couple of month ago on his youtube channel. There is a boost cut down to a half if I remeber correctly. And if you are in the range over 100 degrees it is a loop of doom. You are not able to do more than 2 fast laps in a row.
I am not sure if a oil cooler realy helps, because oil seems not to high at all. May be it is a combination of water and oil cooler.

[speedmachine]

you loose clearly noticeable power. It is around 103 degree water temp and above. I think Simon did some data records on that a couple of month ago on his youtube channel. There is a boost cut down to a half if I remeber correctly. And if you are in the range over 100 degrees it is a loop of doom. You are not able to do more than 2 fast laps in a row.
I am not sure if a oil cooler realy helps, because oil seems not to high at all. May be it is a combination of water and oil cooler.

You have the big intercooler as well?

[salvechris]

jep

[speedmachine]

jep

Than we are all doomed…dont fancy changing my whole engine bay to a gold looking place

[Alec]

When I was on the Alpine Tour back in 2008, something got sucked in and jammed the Radiator Fan causing it to fail.
Unfortunately, the Support Vehicle had virtually everything, including a Radiator, but didn't have a Fan, so it couldn't be repaired.
Although I kept an eye on the Temperatures, it did run a bit higher at times, and it must have been that that caused a further problem, which only became apparent when we arrived back in Dover and I called the RAC out.
What he found, was with the slightly higher temperatures, one of the Rubber Hoses had become so soft that it had started to slip off the metal spigot it was attached to with a Jubilee Clip, which he just had to tighten to cure the problem.
He reckoned I was then safe to drive it back to Liverpool, but offered to transport it back under my Membership, which I accepted.
I then bought & fitted a new fan myself.
The point I'm making is, if the Temperatures are going to get very high, and consequently the Water Temperature may increase, I would suggest a sensible thing to do is that you check & tighten all the Jubilee Clips in the Coolant System.

[abcoro]

you loose clearly noticeable power. It is around 103 degree water temp and above. I think Simon did some data records on that a couple of month ago on his youtube channel. There is a boost cut down to a half if I remeber correctly. And if you are in the range over 100 degrees it is a loop of doom. You are not able to do more than 2 fast laps in a row.
I am not sure if a oil cooler realy helps, because oil seems not to high at all. May be it is a combination of water and oil cooler.

Exactly what I experienced, power drop around 103 degrees. While I could run to around 195km/h when all normal on the straight, I only reached around 175km/h when the engine was in safe mode. Missing a lot of power also in exit of turns, so probably the turbo gets cut down sugnificantly at that point. Really hoping the factory can come up with a good solution.

[autobackup]

When my Atom was completely stripped right back to the bare frame by the Ariel factory during 2018 the frame went back to the fabricators to then modified/upgraded to the full 3.5R spec and then re-powdercoated with the latest Gunmetal then rebuilt by the factory from scratch as a 'fill blown 3.5R (albeit without the sequential gearboxp!)

As I live in Cyprus one of my main concerns, what with the extra power, was cooling - so after a long discussion with Rookie the 'hot weather' radiator (extra horizontal radiator) option was rejected in favour of retro -fitting the extra large (thick) Atom V8 radiator with it's oversize fan.

This has effectively kept the engine temperature under 95°C in ambient temperatures up to 43°C even when 'playing' at Achna Raceway!

[Monza]

The water cooling is no longer a problem on Atom 2, 3, or 3.5 because solutions exist : electrical water pump (if not fitted), big front radiator , or despite what Steve is saying, second horizontal radiator with fan, which is, by far, the best water cooling solution.
The 3.5R of [mention]autobackup[/mention] is not an accurate example to solve the problem on other Atoms 2, 3 or 3.5 because it already has an oil radiator + a charge cooler which helps to solve the water temp. problem.

For the Atom 4, even with all the good options on the list , there is no solution at the moment on track when ext. Temp is higher than 28 or 30°c (depending of the track) , and to my opinion, the only good one will be a second radiator with fan.

[anx10us]

I'm at Bedford GT tomorrow, 37 degrees in the afternoon, will be interesting to see if I can get a single fast lap in without temps hitting over 102 and power being restricted ..

[wasp]

I'm at Bedford GT tomorrow, 37 degrees in the afternoon, will be interesting to see if I can get a single fast lap in without temps hitting over 102 and power being restricted ..

It will be interesting to hear back after your day. I suspect if you have wings you're gonna struggle!

Hope you have a great day though.

Cheers,
Stu