The curious case of the Atom 4 Cooling

[Curves Junkie]

I am out in my Atom at Blyton Park on sunday so should know fairly quickly whether the "Race Ready" no antifreeze coolant i have in mine has made any difference. I was also going to try the deflector plate in front wing see if that alters anything and may even try no front wing again to see if any difference.

You mean this air catcher you had written her in this thread at Jul, 26?

Will report back once i know

Yes, please absolutely.
I'm very curious about the result or the effect.

[plip1953]

Possibly the aftercooler eats the hot air of the water cooler. Try to install a horizontal cover at the front behind the rad so that the hot air does not come under the car, but is only discharged to the side.

But none of these include shutting off the option for hot air from the radiator to exit downwards, but it's certainly something else to consider.

It's a consideration of mine.
At the moment I can't find an explanation why after the Bentley section the AIRT rises so much and especially so fast.
My suggestion is thought, according to the exclusion method, that it is not due to the hot air running along the underbody.

Just take a cardboard cut it to size and tape it to the horizontal tubes with a panzer tape.
It may be that ECT rises even further - but it doesn't matter in this case - we want to know only how AIRT is doing.

I hope you understand my bad English.

Your English is very good, and thank you for your questions, challenges and input of ideas. The more we all share what we know, or what we think we know, the sooner we are likely to find solutions :-)

[Yorkshire]

It's a consideration of mine.
At the moment I can't find an explanation why after the Bentley section the AIRT rises so much and especially so fast.
My suggestion is thought, according to the exclusion method, that it is not due to the hot air running along the underbody.

Just take a cardboard cut it to size and tape it to the horizontal tubes with a panzer tape.
It may be that ECT rises even further - but it doesn't matter in this case - we want to know only how AIRT is doing.

Something i just realised which may mean this is not the case of hot air from the front radiator running under the body into the intercooler. When my car was last on the dyno (i realise slight differences to actual on road/track driving) but we had a large fan blowing on the front of the car as normal but i also made an adaptor plate for the inlet of the intercooler out of plywood that was taped in place with a 4" pipe adaptor straight into its centre. This was connected to a smaller fan which just blew cold air straight through the cooler so no air from anywhere else entered. Whilst it kept the IAT down for pulls we still had exactly the same thing with IAT rocketing when off throttle after a pull.

I assumed it must be heat soak from the lower volume of air now going through the hot intake system.

[plip1953]

At a trackday tomorrow at Cadwell Park we'll be trying out the latest version of additional measures to tame spiralling coolant temps when pushing hard on track. Right now the mods aren't especially pretty to look at, but that's not a concern or priority right now. Results from testing will hopefully take things forwards rather than backwards, but we aren't expecting miracles.

[Curves Junkie]

[mention]plip1953[/mention]
If the factory have installed the engine, turbo, blow-off and sensors as Honda do - the rising AIRT after lifting the throttle is normally and no problem.
[mention]Yorkshire[/mention] has already confirmed that the temp rises, although he has supplied the cooler air externally.

[plip1953]

@plip1953
If the factory have installed the engine, turbo, blow-off and sensors as Honda do - the rising AIRT after lifting the throttle is normally and no problem.

Yes, entirely as per factory spec. And good to have it confirmed that off throttle temp spikes are not a problem.

At yesterday's Cadwell Park test day we didn't see coolant temps go above 96degC whereas in similar ambient conditions we've routinely seem temps well over 100degC. Essentially this was achieved by routing additional airflow directly to the radiator. Will now evaluate whether this lays the foundations of a permanent fix or whether we go on to try out a number of other options.

[Curves Junkie]

At yesterday's Cadwell Park test day we didn't see coolant temps go above 96degC whereas in similar ambient conditions we've routinely seem temps well over 100degC. Essentially this was achieved by routing additional airflow directly to the radiator. Will now evaluate whether this lays the foundations of a permanent fix or whether we go on to try out a number of other options.

This sound really good.
If you want - send me your solution by PM.

I am and really do not want to gloat, but I had already raised the issue here in this forum viewtopic.php?f=1&t=17608 in July 2019 and was only attacked by other users.
Now we have to make the best of it so that the success story of the Atom 4 continues.

Note that you also need to find a solution for the outgoing air behind the rad.

[reg]

Yes, entirely as per factory spec. And good to have it confirmed that off throttle temp spikes are not a problem.

At yesterday's Cadwell Park test day we didn't see coolant temps go above 96degC whereas in similar ambient conditions we've routinely seem temps well over 100degC. Essentially this was achieved by routing additional airflow directly to the radiator. Will now evaluate whether this lays the foundations of a permanent fix or whether we go on to try out a number of other options.

Does the aero compromise the cooling as much as it appears to? I’m not sure why but mine seems to run reasonably ok, although it has only had one track outing so far. I did spec the bigger rad setup as Tom said it was needed, albeit they reckoned the IC was fine. Mine has always been decatted, not sure if this keeps some temperatures down in the bulkhead and if this has any impact on overall coolant temps?
I do remember that whilst the 3.5 never seemed to get as hot (coolant wise) it also suffered with power loss due to heat soak, nobody seemed to complain much about it, but it was always a thing with Ariels.
The winter plan will be to explore moving the IC to the rear of the car, so it can be much larger. It’s already been done in the US, so hopefully the pipework won’t affect the drive? Then see if a silencer can be made to fit where the original IC sits….and what benefits or downsides there are. Keen to see how the improvements pan out. All looks positive.

[Monza]

What was the exterior temp at Cadwell when you were driving ? If it was less than 26°c outside , it is much more difficult to see water temp going higher than 100°c. Of course this depend of the track but this is what we have seen here on Atoms 4 in July between the morning and the afternoon (hot days). Till 26°c, all was fine, 28°c was the limit with Atom 4 between 103 and 106°c and when higher than 28°c : overheating more than 106°c.

[plip1953]

What was the exterior temp at Cadwell when you were driving ? If it was less than 26°c outside , it is much more difficult to see water temp going higher than 100°c. Of course this depend of the track but this is what we have seen here on Atoms 4 in July between the morning and the afternoon (hot days). Till 26°c, all was fine, 28°c was the limit with Atom 4 between 103 and 106°c and when higher than 28°c : overheating more than 106°c.

The morning temps were 17-20degC, but in the afternoon it warmed up to around 24degC. Previously we've seen coolant temps of well over 100degC on cooler days than that. For example, 108degC when the ambient temp was only 15degC!! But I think it's worth bearing in mind that the guy who was driving the car at the time is a really quick driver and was extracting pretty much everything the car could offer over multiple consecutive laps.

[plip1953]

Yes, entirely as per factory spec. And good to have it confirmed that off throttle temp spikes are not a problem.

At yesterday's Cadwell Park test day we didn't see coolant temps go above 96degC whereas in similar ambient conditions we've routinely seem temps well over 100degC. Essentially this was achieved by routing additional airflow directly to the radiator. Will now evaluate whether this lays the foundations of a permanent fix or whether we go on to try out a number of other options.

Does the aero compromise the cooling as much as it appears to? I’m not sure why but mine seems to run reasonably ok, although it has only had one track outing so far. I did spec the bigger rad setup as Tom said it was needed, albeit they reckoned the IC was fine. Mine has always been decatted, not sure if this keeps some temperatures down in the bulkhead and if this has any impact on overall coolant temps?
I do remember that whilst the 3.5 never seemed to get as hot (coolant wise) it also suffered with power loss due to heat soak, nobody seemed to complain much about it, but it was always a thing with Ariels.
The winter plan will be to explore moving the IC to the rear of the car, so it can be much larger. It’s already been done in the US, so hopefully the pipework won’t affect the drive? Then see if a silencer can be made to fit where the original IC sits….and what benefits or downsides there are. Keen to see how the improvements pan out. All looks positive.

Anecdotally there does seem to be a bit of a difference re cooling temps (ie lower) with the front wing temporarily removed, but at the time this was tried the driver admitted he wasn't pushing quite as hard in case the wing actually made a difference to front end handling behaviour. But the path we're following assumes the front wing will always be fitted and we therefore need to compensate for any effects it might have.

What's causing you to want to change the intercooler? Lower charge temps is of course always nice to have, but the data we have to hand doesn't suggest that it's too much of an issue - ie compared to coolant temps. Similarly we are reasonably content with what we're seeing by way of oil temps, albeit we now have an oil cooler.

[reg]

The conversation with a couple of tuners has led me to believe fitting a more efficient IC will free up some power and keep the intake temperatures lower. It made a huge difference on the Noble. Also moving the exhaust seems semi sensible given the manifold exit?

[Monza]

Of course but you'll not be able to do 2 consecutive laps because of water coolant temp ....

[plip1953]

Of course but you'll not be able to do 2 consecutive laps because of water coolant temp ....

I'm not quite sure what you mean? In the last session of the day, finishing at around 3pm when ambient temps were pretty much at their highest, the car completed 11 consecutive 2 miles laps without any kind of attempt to let things cool down at any point.

[Monza]

Was answering to Reg i imagine that after your coolant modifications you can do several laps as you wrote, which is a good thing and which confirms my opinion that a second radiator with fan will be easyest and lower cost mod to solve the collant T° problem.