Ariel.Club Forum

great write up, keen to see how this progresses.

Fantastic write up and very informative. Thanks for sharing and looking forward to hearing (and seeing) how development goes.

Chris's car has consistently been run on factory (track) damper settings. Cambers at -2 all round seems to be ok, although I think we've tried a bit more at the rear. But what it seems most sensitive to is toe settings in order to keep the rear from being too lively. I think we're currently at a smidge of toe out on the front and total of 4mm in on the rear. And I believe that's really not very different to factory recommendations.

In due course we may try out stiffer springs, mainly because this is what's recommended when running slicks.

Great thread - what changes to geo and alignment did you make?

Also have you played with the damper settings much - was thinking yesterday that currently theres really only track and road settings listed, but should also be wet settings?

Loving the commitment to getting it also sorted :tu:

Looking forward to 2023 and the challenges it presents.
Thank you to all the customers that we have worked with and entrusted us with their projects.
Exciting times ahead 🏁

Hi Chris, was great to have you guys around last year. Invaluable feedback to a host of issues that, to be frank, some said either didn't exist, or were very likely one off :doh:

WIthout doubt one of the most comprehensive write ups on the 4. Very much looking forward to seeing what the brake package is like and how your other mods further enhance, what is a mega base in 2023.

The Atom community is literally nothing without guys like yourselves, Ian, and many others all putting time and effort into solving these problems so that everyone can benefit :tu:

Thanks for documenting that, look forward to what you have coming this year.

Another great detailed write up and a lot of money and time spent looking to my make the Atom 4 nearly perfect!

Look forward to reading Stuarts journey soon.

Cheers

Daz

Part 3 of my Atom 4 Journey

Anglesey, 21/22 June.

This was my first time at Anglesey and what a great circuit. The Mono boys were there too and it was great to have a chance to play alongside them. They were all great company and had support from the BAC factory on hand. At the end of Day 1 we all stayed behind as Top Gear Germany had booked the circuit for filming of the latest Mono R with a pro racing drivers doing their stuff…just amazing. I think having technical support and coaching from the factory go hand in hand as everyone gets something out of it … especially the customers as not everyone is a racing driver and we do this for our enjoyment and at great personal expense.

So Paul and I set the cars up in an adjoining pair of pit garages. Phil had produced a full agenda for the two days of testing with Marc on hand for tuition and further car development… the Mono boys later commented that they thought we were the official Atom development team… funny that.

[attachment=14]All set up and ready at anglesey.jpeg[/attachment]

[attachment=15]Lineup at Anglesey.jpeg[/attachment]

After the last track day at Cadwell Park I asked Ben to remove the radiator fan in an attempt to see if we could improve the airflow out the back of the radiator as it might make a difference on the overall cooling front. And just in case you were wondering, back in the pits we had a powerful leaf blower to fit into the front nosecone and another big fan to direct air at the engine itself. Very F1 …. Not

[attachment=16]Leaf blower.jpeg[/attachment]

Shortly after Cadwell Phil discovered that the AP brake calipers don’t have anti-knockback springs fitted as standard, contrary to what he’d previously assumed. Most AP calipers do apparently have them and they were definitely fitted to the Alcons that seemed to be so effective on the previous Atoms. So a set of 16 springs were then duly fitted at home in my garage by four of us in a bit of a production line process. I think we did ok and had some good banter along the way.

[attachment=17]X 16 anti-knockback springs.jpeg[/attachment]

We also tried something bit a radical with the geo … which turned out to be a big mistake as can be seen by Marc having a right old time wrestling with the car on a proper hot lap, and he still managed a quick time. But we did at least managed to get the front slicks working properly for the first time. Note. Anglesey is a very abrasive circuit and we used a full set of new Avon Slicks over the 2 days.


We were also trying a revised version on the capped engine mounts to see if we could reduce the vibration/harshness and at the same time prolong their life.

https://www.youtube.com/shorts/bH__Faaifn0

So we all went out for the sighting laps and then to the main business. The weather was brilliant and we had great optimism about how things would turn out. But after just 4 laps Paul pulled into the pits complaining of a noise at the back of the car. It turned out that he had literally ripped his offside engine mount from the main chassis tube! The Mono mechanics kindly helped to remove the broken bolts and Steve at Ariel was contacted and promised to urgently despatch a replacement set of mounts. Unfortunately they arrived too late the following day for Paul to be able get any further tracktime. One very disappointed Paul and unfortunately all the back-to-back testing that we’d planned went out the window.

[attachment=12]WhatsApp Image 2023-01-10 at 11.49.48 AM.jpeg[/attachment][attachment=13]WhatsApp Image 2023-01-10 at 11.50.07 AM.jpeg[/attachment]

However, we did discover that the anti-knockback springs seemed to work well and kept the brake pedal consistently firm and with reduced travel. Anyone still unhappy with their AP brakes might benefit from doing the same, and it seems that the factory has endorsed it as a worthwhile addition. Hopefully, that would now put to bed any further question/concerns over the brakes (well nearly so – more will follow later). At some point Phil has promised to put together a technical piece on the brakes in general, but I suspect many will get bored and switch off after a few sentences lol. Bless him!

My newly modified engine mounts were still causing too much harshness, so back to the drawing board on that one again.

Oil temperatures were monitored over the two days and never rose above 100C, so we were pretty happy at that, but couldn’t be sure as that might be mostly down to having the oil cooler. We don’t think so, but during 2023 we will try running without the cooler and see what happens.

But sadly we were still struggling with excessively high coolant temperatures, so removing the fan to try to improve airflow through the rad core didn’t appear to help, but with Paul’s car out of commission from the get go we once again couldn’t make any back to back comparisons. I don’t think it’s been mentioned before, but as soon at temps exceed an indicated 100C the ecu starts to reduce turbo boost and we’re told that timing is also retarded to some degree. And the boost cut is not by a small amount. At temps below 100C max boost is generally around 1.25bar, but once temps get as high as 106C it’s down to just 0.75bar. That’s a big difference so no wonder performance starts to feel dull!

Overall, however, it was a very enjoyable couple of day, and Paul’s patience and stoicism at going all that way for virtually no tracktime is to be admired. I know we’re all looking forward to this year at Anglesey as things have certainly moved on and the full team will be there including Ben from Corten-miller.


Snetterton, 1st August

The usual team of me, Phil, Marc, Richard and Paul were all there, although Paul opted to drive his Radical that day. After his issues at Anglesey I can’t blame him.

A further revised geo was now on the car and finally it worked and we also found that a set of new Hankook slicks worked really well. At an earlier point in the year we had considered lowering the car by around 10-15mm. However, Phil wasn’t happy with the upwards angle this would result in on the rear lower wishbones. Something about upsetting the dynamics of the suspension, and roll centres but all of that was over my head! Nevertheless I bowed to his objections, mainly because I had discovered that Hankooks have a 20mm lower rolling diameter than something like an A052s. So everyone was kept happy. Plus it worked so well.

The brakes are still feeling great and Phil’s insistence on big G numbers was fully met – consistently -1.2 to -1.3g which apparently is pretty good, although he says his target (for slicks) is -1.5g. Just as importantly the pedal remains nice and consistent and its starting to give me much greater confidence in the brakes in general.

On cooling I knew we needed to start being a bit more imaginative in our approach so decided to create some extra ducting of air into the front radiator. I’d managed to acquire a damaged front nosecone and I asked Ben to mount x2 NACA ducts with 70mm hose directly into the radiator. We then ran back to back with the ducts taped up and then open, unfortunately it made little difference as temps peaked at 108C on both runs. So in spite of our various effort so far we had effectively made zero progress.

[attachment=11]70cm NACA ducts.jpeg[/attachment][attachment=10]Holes cut out in inner ducting.jpeg[/attachment]

We also tried running with an extra rigid engine mount stay which improved the general feel of things from the cockpit, but then had the unwanted effect of making gearshifts feel very harsh. But at least on this one we seemed to be making some progress.

[attachment=9]WhatsApp Image 2023-01-12 at 8.40.18 PM (1).jpeg[/attachment]

Marc annoyingly set an amazing time on the new slicks, and he was almost happy, although he really wanted to get below 2mins.

So back to Ben with a load more challenges to solve - once again.


Cadwell 18th August

Cooling, or the lack of it, was really starting to haunt us, that’s being polite! But with limited time available I asked Ben to increase the size of the nosecone ducting to 100mm, but also to draw clean air in form the front of the car to get a cleaner airflow. However, who really wants to cut holes in the front of their very expensive nosecones. So whilst we gave it a go we didn’t think it could produce a longer term solution. And in light of that we were already on with a completely new plan. Nevertheless, it’s worth reporting that running the same back to back test with the enlarged ducting we did see a noticeable drop in coolant temps – even as much as 6-8degs, but Marc wasn’t on hand on this occasion so the car probably didn’t have as hard a workout as previously.

[attachment=6]Nosecone nostrils 3.jpeg[/attachment][attachment=7]Nosecone nostril 2.jpeg[/attachment][attachment=8]Nosecone nostrils.jpeg[/attachment]

One more thing – mainly to keep Phil happy I agreed that Ben should fit a rear brake proportioning valve. The idea was that this would then allow me to run closer than before to 50:50 on the pedalbox brake balance setting – which is a good thing. He has explained to me how these things work, and it’s not as simple as you might think, but in any case it was mostly in one ear and out the other. But in practice it works really well.

[attachment=5]Rear brakes proportioning valve.jpeg[/attachment]

Ben also came up with a very neat solution to the engine mount issue by incorporating a damper into the new engine support strut. In the time available the new version was only mounted on one side of the engine, but the effect was brilliant – all of the plushness of the standard feel, but almost total elimination of the lateral forces on the OE mount which seems to be causes them to fail… a great result. A production version for both sides of the engine will be available through Corten-Miller shortly.

But if it’s not one thing it’s another and this time we could feel another type of vibration coming from the rear of the car. And it didn’t take long to realise the driveshafts were on their way out. So at that point we called it a day…

I’d Just like to say that Steve got the new driveshafts up to CM the next day (excellent service from Steve and the Ariel parts team). I might add that around this time we also discovered that one of the rear Ohlins dampers was leaking, and this was also changed FOC and turned around in a matter days. And that was our last track day of 2022

28th August to 7th September

The amazing Pyrenees trip.

I’ll let Richard Patrick my great friend and ex Lombard RAC navigator do a fuller piece on this at a later date as he’s much more eloquent than me, but needless to say I was a little sceptical about the trip having done similar before – but how wrong I was!

The Atom in the mountains is simply stunning… however we did run out of rear brake pads, possibly because I was left foot braking and having way too much fun .We also took on some dodgy Spanish fuel so the car was then missing, got a puncture on a Sunday morning with everywhere closed and finally the turbo actuator packed up on the way back to the ferry but we got home ok …

[attachment=2]Atom 4 blocking another nice mountain view.jpeg[/attachment][attachment=3]Mountains with an atom blocking the view.jpeg[/attachment][attachment=4]Chris and Richard in the Pyrenees.jpeg[/attachment]

But it was all just part of a memorable adventure, plus other great Atom owners, and all credit must go to Graeme Weineck for organising a brilliant trip.

Specifically for this trip, and in very short order, Ben converted my car back to standard, fitted the new driveshafts and made a pair of side panier mounts which worked perfectly.

[attachment=0]With panier in situ.jpeg[/attachment][attachment=1]Panier bag carrier.jpeg[/attachment]

So that’s where we draw to a close in 2022, but we have a few new ideas for the Atom going forward and now that we’re also working alongside Stuart Drewell with big plans including his 500+bhp 4Piston engine, which I know he will document once it’s all running.

I will endeavour to keep you all updated as things progress – in particular re the following….

Cooling - with a new rear mounted radiator specially developed by one of the country's leading motorsport aftermarket manufacturers/suppliers, we will be transparent about in all of our findings. We will also be running with an array of additional high quality temperature sensors whose outputs will be channelled through to a receiving device than can then transmit them via CAN to (most likely) a Racelogic Video Vbox. In the interests of transparency we want to be able to show our collected data in a fully visible and real time way.

New intercooler with better airflow and a different type of core.

Modifications to the fuse box to minimise over heating of the fuel pump relay

New braking system, comprising AP Racing 5000R calipers running specially made Pagid RS14s and the option of a new floating disc and bell assembly. NB if preferred the calipers can still run in conjunction with the OE Atom disc and bells.

Bosch M5 motorsport ABS with a major upgrade to the pedal box incorporating compatible ABS master cylinders plus a bespoke motorsport wiring loom. We believe this will be a major step forward in the braking department, and thanks to Stuart for helping with the joint development costs.

New engine mount damper kit

And last but not least, airjacks, which will just make life easier as the car seems to spend
most of its time with its wheels off.

I’ll also ask Phil to do a piece on wheels and tyres as things progress next year as we mainly run 15" front wheels because there is a much better selection of tyres to choose from compared with the OE 16".

I hope this helps and as ever this is only my opinions on my car. I very much welcome and respect what anyone else might want to throw into the mix.

Great write up! Hopefully by the time I'm back in an Atom, it'll be a fully sorted track animal thanks to the work that you guys are all putting in!

Great write up, hopefully 2023 is the year of solving niggles, over heating is a definite issue for me and others, I'm less concerned about the brakes ... Massive respect for the amount of time and money that is being spent in getting the Atom to 100% ...

Looks like I need to get Cadwell booked for 2023 as well ;-)

Part 2 of my Atom 4 Journey

But first, a quick recap on where we’d got to by the end of 2021.

Although this is my first Atom, it immediately got under my skin and I recognised its potential to be a great trackday toy as well as a useable car on the road even though equipped with the optional out and out motorsport sequential gearbox - which I personally find effortless to use on the road.

[attachment=9]Car on track at Cadwell.jpeg[/attachment]

But we’d also started to unearth quite a number of challenges with the car, both technical but also in terms of getting to grips with the setup requirements of a rear engine, rear wheel drive car with a power to weight ratio of well in excess of 400bhp/tonne…. Even with the full aero kit it only weighs 805kg all up including driver and a full tank.

Not much went on during the winter months. We’d previously identified a potential issue with the brakes, but after fitting the Corten-Miller pedalbox brace, changing master cylinder sizes, swapping to Pagid RS14 pads all round and making absolutely sure there was no air in the system, we thought it was all sorted. But that turned out not to be so!

An issue with premature failure of the engine mounts was also identified, but we still had work to do to find a geometry setup that truly tamed the rear end of the car, but at the same time retain good front end turn-in characteristics. But something else I forgot to mention was that Ben found an issue with the bolts holding the lower engine mount in place. Although appearing tight there was movement in the bracket and it turned out that Ariel must have used bolts that were too long. Thankfully an easy fix and no obvious harm done.


[attachment=8]Lower engine mount with loose fitting.jpeg[/attachment]


Fast forward to 16 March for a trackday at Cadwell Park

The then current brake setup appeared to be working well with some really good “G numbers” (rate of retardation) being achieved. Phil monitors these numbers like a hawk, and he could easily bore the pants off you with what they tell him, but suffice to say I could feel a positive difference and was starting to gain a lot more confidence in them. Nevertheless, by the end of the day the pedal was going long again, which caused a bit of head scratching again.

Marc wasn’t available for this first trackday so we didn’t make any further progress on setup in general.

Next up was 15 April for another Cadwell trackday, but this time we had both Phil and Marc along as well as my good friend Richard Patrick and another good friend Paul Richards in his almost identical Atom 4.

This trackday proved to be something of a watershed moment because it was the time we first encountered overheating!

In the morning the car had been going really well, but as ambient temps went above 18C it was noticeable to both me and Marc that the performance was feeling dull. Also out on track that day was an almost brand new Cupra TCR race car driven by a customer of Corten-Miller. Earlier in the day both Marc and I had been able to pull away from it down Park Straight, but the tables were completely turned in the afternoon. Between us I think the highest temperature we saw that day was 107C!

[attachment=2]107C coolant at Cadwell.jpg[/attachment]

Cooling issues aside, Marc reckoned he’d figured out what was going with the handling so hopefully that could be sorted properly for the next outing. I’d also like to add that the stock Atom 4 track setup is very good as per Paul Richards’ car as I was able to do a proper back to back test. I think ours is better now, but boy was it challenging because as ever it’s also down to tyres, driving style and how confident you feel on the day.

Over the next five weeks we kept Ben at Corten-Miller very busy indeed. First he arranged to have various engine parts insulated/shielded using Immico thermal insulation products. Very nice stuff and reassuringly expensive too, but very difficult to truly quantify exactly how much it has helped.

[attachment=4]Immico 2.jpeg[/attachment][attachment=3]Immico group.jpeg[/attachment]

Ben also fitted an oil temperature sensor in the sump (so we could see if oil temps were going very high). Why on earth there wasn’t one in it already is a mystery. Ideally we would have liked for it to report via the dash, but this would need access to the AIM dash configuration and Ariel have made it quite clear that that isn’t an option they’re prepared to entertain. So instead we added a basic circular analogue gauge that was in the view of the Smartycam so we could view what it was reporting while on track. And while Ben was at it he fitted an oil cooler – what a work of art! An oil temperature sensor was also fitted to Paul’s car, but no oil cooler, just so we had something to compare against.

[attachment=5]Oil temp gauge.jpeg[/attachment][attachment=10]Oil cooler installed.jpeg[/attachment][attachment=11]Oil cooler 2.jpeg[/attachment][attachment=0]Another view of the oil cooler.jpeg[/attachment]

We also set Ben on the path to finding a solution to the engine mount issue. The first idea was to fit a metal cap over the top of the rubber mount, essentially to keep the rubber part from moving around so much under load, but this resulted in a nasty harshness that could be felt from the driving position. So Ben then proposed that he fabricated an additional diagonal support rod with a built-in damper. Initially he made one for the offside and it worked really well. Designing something for the nearside has proved a bit more tricky, but both should be on the car for the first trackday in 2023.

[attachment=1]Engine mount with cap.jpeg[/attachment]

[attachment=7]Engine support with damper in situ.jpeg[/attachment]

[attachment=6]Engine brace 1.jpeg[/attachment]

But back to 2022.

May 26 Cadwell Park - on A052s pretty much all day

We like Cadwell Park! The usual team were all assembled and this time we were hoping in particular that the cooling issues might have improved. Sadly that wasn’t to be the case and during one session later in the day, with Marc really pushing on, we once again saw 107C. But at least we were grateful that oil temps looked ok at no higher than 100C. And oil temps were similar on Paul’s car so probably no need for the oil cooler after all.

Notwithstanding these crazy high coolant temps Marc managed an outstanding laptime of 1min 32. Tom Deacon also happened to be there that day and managed a 1min 34 which was also extremely creditable, especially as it was his first time at Cadwell, but he unfortunately managed to damage his engine mounts. I think my best was a 1min 35.

It's worth emphasising that these times were all achieved on semi-slick tyres. At one point we tried slicks, but although they felt good the laptimes were weirdly slower rather than faster. Marc and Phil have shed load of experience with cars running on slicks at Cadwell and the difference is generally several seconds. So yet another problem to solve.

Something else that was on the car for the first time was data logging directly off the dash. Although the OE dash configuration is locked we discovered via former Atom 4 owner Simon Hart that fitting an AIM Strada Logger was literally plug and play and would then capture and log everything that could be viewed on the dash. This made Phil very happy indeed!

Next up will be two great days at Anglesey and then on to Snetterton and another Cadwell.

It's really interesting to look back on the first part of Chris's Atom 4 journey through to the end of 2021, but boy o boy does it pale into relative insignificance compared with what transpired in 2022!

Hi Chris
Great start now where’s the rest
Looking forward to the next episode

The knock back springs came later in 2022 as we were still trying to figure out where the real problem was.
The springs do solve part of the problem but It all depends on how much track you do and how you feel about the brakes. I’ll get into this more as the story progresses.