A Diary, by Dez Chand, of team ‘Chand-a-Cola’, 24 Hrs D’Ardent
June 11/12th '11.
The original concept was to race a RTR HPI Sprint2 Porsche over the same 24 hours as the Le Mans 24 Hours. Just like any other race meeting, only longer, but for one exception; you could only marshal your own teams car, with a penalty for both teams if you touched or marshalled another car, which was a master stroke because this must be the one and only race I’ve ever been too where I didn’t hear those immortal words “BL**DY MARSHALS!” This simple rule kept everyone on their toes, and there’s something quite satisfying about standing next to someone’s car you could help but were not allowed to, knowing full well their demise was your bonus, and no one could swear at you for not leaping to their aid! Besides, trying to enforce a rule whereby each marshal point had to be covered for 24 hours would have proved way too problematic for race control.
We’d be using kit tyres and motors, with the promise of a better specification speed controller to include LiPo protection, which were sadly delayed so we had to use the original kit speed controllers, therefore the first challenge was to build in some sort of LiPo protection, either a low voltage cut off or low voltage warning to avoid under discharge damage to a valuable LiPo, which is usually permanent, even dangerous!
Initial testing found the 15T Saturn motor was a little fast, and far too fragile to be a viable option for a 24 Hr race so it was decided to drop it in favour of the 20T Saturn in a bid to make the cars slightly slower and much more reliable. The 27T Saturn was deemed just a little too slow, though in hind sight it may have offered a longer life span, but that’s half the fun and challenge of an endurance race, making your equipment go the distance!
The most important and difficult change to the rules was the final choice of tyre, as the kit D compound tyre was found to be more about drifting than racing, and the damage we did in testing trying to make the chassis race on these tyres defied belief; I have a pile of plastic parts, hub carriers, lower suspension arms and castor blocks which prove the two sessions we did at Ardent plus a few other local club meetings in search of the ideal chassis set up to suit the tyres was completely fruitless, and a very expensive way to go racing. HPI were desperate to keep the tyre choice within their product range, but eventually the Sorex 32 was chosen from Schumacher as it was a known quantity; a hard wearing tyre that could go the distance while offering predictable handling. Our car was instantly transformed and even on kit settings the car was in the groove, once the tyres were buffed and additive applied of course.
Having raced and maintained a HPI Sprint2 previously, I knew it was a rugged chassis and my only real concern were the drive belts, knowing how long they take to change, so I made it my priority to have spare belts in place on the chassis ready to slide into the pullies. It was an engineering challenge but I managed it eventually and my team had an immediate advantage which would surely play into our hands as the race went on. Having visited all the pit benches it was obvious no other team had spare belts installed, so my team were elated!
If you get a 5 minute practice, four 5 minute races and a 5 minute final at a regular club race, then 24 hours represents 48 race meetings end to end, that’s a regular race addicts whole year, so we were expecting belt problems at some stage. What we hadn’t counted on were the belts lasting much better than expected due to the low powered motor and fairly clean indoor track conditions compared to an outdoor circuit. We experienced a lot of fluff build up on the pulley teeth in practice and expected that to play a part, but knew that as the track cleaned up it would diminish, but over 24 hours we didn’t even have to clean a pulley out, let alone snap a belt, so our strategy didn’t come into play unfortunately, though I did see several teams changing belts, notably rears which were more likely due to picking up lost screws and plastic fragments from the track. Especially teams like Stoke who added a tensioner to the rear belt like the one fitted as standard to the front belt, so any debris that was sucked into the belt had no slack to allow it to pass around the pulley and it would simply snap, forcing another half hour pit stop, which they did twice!
What we had not expected was the wear rate of all the metal parts, the diff out drives and stub axle cups were grinding themselves to death against the dog bone drive shafts, and within a couple of hours we all saw great slots appearing, causing no end of handling problems as they jammed and locked, especially on the fronts where they affected the steering severally. Pitting for new axles and out drives solved all our handling issues at a stroke. The kit diffs are just lightly greased and spin very freely, and a couple of teams actually finished on the original cups and axles with little or no wear at all, but teams running a stiffer Diff to get a little more under steer and better stability (and some were very stiff indeed, almost a spool) were eating through drive cups and stub axles faster than anyone else, so the trade off for a stable handling car was increased repairs and maintenance.
Also we were splitting the Sorex 32 tyres rather than wearing them out, as they were getting pinched against the rims in crashes and slicing the sidewalls which were already under stress because the blue kit insert does not fill the tyre and the centre remained polished. In testing we found the centres of the tread remained shiny for many hours as it was simply not being used. We had prepared the rims with abrasive pads and lighter fluid, the tyres likewise, so once glued they remained intact throughout the meeting, and it was a case of juggling the tyres to keep one good set on track, but it was a very fine line indeed and a few teams ended up running the kit tyres for the last few hours, while everyone else only used them when the wet sessions were imposed on us by race control. These wet periods definitely spiced the event up, forcing everyone to scramble to the pits and change wheels as fast as possible. The fronts are 3mm offset, while the rears are 6mm offset, and I’m sure some teams certainly fitted the wheels front to back, as all sorts of handling problems were caused by rushing the wheel change to wets or back again. Fitted in pairs to the wrong end is bad enough but get them staggered with a 3mm and 6mm on each axle, or diagonal across the car and you had all sorts of strange handling issues. We had chosen to buy white rims to suit our colour scheme and we could simply colour in the nut seat/wheel hex to identify the rears, so we never once suffered this particularly annoying failure mode.
Preparation is Key
Some ingenuity in the pits was seen, a few raised decks to squeeze in thicker high capacity battery packs, which also required the lower run of the front belt to be lifted by turning the belt tensioner over to run on the bottom and lift it clear of the battery pack below, personally I think that’s a mistake because you are loading the working side of the belt instead of the return slack side, but hey what do I know! A few teams had quick change battery systems though I timed them and their changes were no quicker than ours, just using an idiot proof plug system. Most noticeably the winners Team Doris, had reversed the fit of their diffs so the belts ran on the wrong layshaft pulleys, but why you ask, as did I? Simply so they could remove just one chassis side brace and change a rear belt in less than ten minutes, that’s why! Sheer brilliance and certainly the result of either insider knowledge (HPI’s own James “Part Number” Stewart was on their team) or previous bitter experience with a similar belt driven touring car.
For my part I knew the screws all over the Sprint2 were partial to coming loose as the plastic chassis is very flexible and things have a habit of wriggling free, so I thread locked every M3 screw into metal threads, and where screws went into plastic parts I applied a drop of superglue to each. Get out of that! The outer suspension pivot pins are threaded just under their heads and have a habit of backing out so I glued them in also. The suspension arm inner pivots use retaining circlips which are fiddly to remove and almost impossible to refit in a hurry. I hate circlips so I drilled and threaded a grub screw into each suspension arm to retain the pivot pins and speed up component changes. The steering servo saver is prone to unscrewing its tension ring so ours was done up really tight (because we had a durable all metal gear servo fitted) and superglue was applied to keep the threaded tension ring where it belonged, which worked a treat. I saw several teams fall foul of this particular problem which rears its ugly head in terms of a severe lack of steering, so you turn the transmitter dial up and up and up and the car gets more and more difficult to drive, then when you finally figure out why and tighten the ring the cars is all over sensitive and undrivable until you reset your steering dual rates again!
Also, during wheel changes the hex can stick in the wheel allowing the cross pin to fall out of the axle, so a drop of superglue in each hex held it tight to the cross pin and made wheel changes so much simpler. I would have fitted a clamping hex to each axle but that wasn’t in the spirit of the event which focused on using the basic car in its simplest form. Another tip I learnt the hard way was to glue the nuts inside the gearbox housings, they are not nyloc because there just isn’t room next to the diffs and if you remove the screws to access the diffs the nuts typically fall out and you only realise they are missing when you’ve got it all back together and the screws have nothing to tighten into!
In short, after a lot of planning, testing with our old Sprint2 and another I bought so we could run two test cars side by side, I spent a dedicated two days on the spanners to tear down and rebuild our new car, until I had a reliable chassis that would stay together throughout the event under the harshest conditions and my modifications would speed up any pit stops for replacement parts. Entering a standard Sprint2 straight from the box would have been mechanical suicide and I wanted an easy life, a pleasant event, maybe even some sleep, and who knows perhaps even a trophy, well that was the plan!
Team numbers were drawn to determine your grid and rostrum positions, it was originally also to set your pit position so any team could be easily located if needed, but sadly that didn’t materialise as team RC Disco ensured themselves a gazebo closest to the cafe, and had their own cut through arranged for easy access to the pit lane and driver rostrum, not only that but they stole both the sofas from trackside and had them installed in their gazebo, rather unsporting I thought, but compared to their driving style it was almost gentlemanly!! Which reminds me, I made large front and rear bumpers to protect our beautiful body work (by Tels Shells) and hopefully reduce the damage of any major pile up!
After the team leaders briefing all of us were grabbing tickets from Johns hand, setting their grid positions, I was one of the last to choose and having turned it over I thought it was number 7, not so bad, smack in the middle of the 15 strong grid, but then it dawned on me it was number 1, and our rostrum position was on the end nearest race control, so we were elated, until we realised we had a huge target on our backs for the early laps! There was no team 6, as only 14 teams started, which was lucky because upside down they could have been mistaken for team 9, Essex Monsters! Team 13 – unlucky for some, was drawn by and certainly suited Team MMR Flux/Chippenham MCC who ate more motors than anyone and soon became known as Team MMR Fux Motors. Sorry guys!
The race was started behind the safety car, fitted with flashing lights and an on-board camera, the footage from which I can’t wait to see! Unfortunately even though they were supposed to be a couple of casual formation laps there were many pile ups and collisions, maybe nerves, maybe lack of talent, maybe something to do with the kit speedo not being so smooth at the bottom and an a little on/off but whatever the reason the expected snake of cars never materialised and the start got under way at just after 2pm (because of a few transponder issues) with a fairly scattered pack scrabbling for the early lead. Our team were under strict instructions to let anyone by, stay out of trouble and minimise the damage and repairs thereof, playing the long game. Others seemed intent on winning all 288 five minute races one at a time and the carnage was obvious! Even when you pull wide to let them by they’d still clean you off the track, and if you passed someone they’d typically T bone you as you brake for the next corner. This began to really annoy some drivers, noticeably my team who were under strict instructions not to get involved in any battles, follow and wait, back off when a group ahead looked likely to collide and in the most part it worked. By driving politely, clean, and keeping calm we were still running even when over half the field were in the pits changing worn or broken parts, we were one of the last teams still running the original motor while some were on their third or even fourth already! That brought the magic back and the plan began to work, we climbed from dead last after a tragic series or crashes in the early laps, all the way through the pack to 3rd overall by midnight, and although it would take a miracle to catch either Team Doris or Team Dudley who were both fast and consistent, it could happen. A broken belt would give us 120 laps back or there about, sadly that plan never materialised, and as our drive shafts eventually wore out the handling began to deteriorate, so our car got harder to drive by the minute, eventually forcing us to do some drastic maintenance which we did in stages rather than change everything at once. Finally we had new diff out drives on the front diff and all four new axles so the lap times tumbled and we were back in the groove though typically wavering between 9th and 4th as the teams swayed between pit stops for damage repairs.
What’s that smell?
It quickly became apparent that motor life was variable, I think team SPC were the last guys running the original motor, over 8 hours life span, but their car was definitely the slowest out there and well down in last place. Some teams were using motors every two hours, some went even quicker, the quickest was about 3 minutes for team MMR Flux who definitely went through more motors than anyone else, with the winners Team Doris in a close second on their 11th motor by the end! They were either shorted out or the internal fan had disintegrated after ingesting a screw or other debris. Mostly it was just grinding to a halt when the positive brush had been used up and the brass spring had been worn away against the comm to the point where contact was no longer made and the car simply stopped. Brush wear isn’t temperature dependant and the magnets on even the most fried motor were still in good condition so in hind sight I don’t think heat sinks and motor fans were of any benefit in this case. If your car stopped you simply looked at the end bell, if one spring was horizontal and the other was angled sharply towards the motor centre you knew why it had stopped and looked no further. Some teams had ESC problems, some by their own hand (plugged in backwards) but a rare few physically melted, so I was glad of having fitted fans to our ESC before the event. It certainly helped keep the brakes working longer than when I tried racing this speedo without any additional cooling!
In the daylight hours cars were easy to pick out, Doris and Dudley were let through as fast as possible and even if they left us pointing in the same direction they simply cleared off. In contrast as teams like Stoke or RC Disco approached we simply side step them in the next corner rather than getting T boned and then began to tail their car at a safe distance waiting for them to plough the road for us, which happened on a regular occasion and we never had to wait long! I picked my way through lots of multi car pile ups simply by remaining calm and calculated. The only part we actually broke in 24 hours was the front castor block and that was still in one piece but cracked through the rear web so it was changed when we did the second set of axles all round, just in case. The regular T bone moves, hour after hour finally took their toll on our battery retainer and we had to change that too, but other wise our car remained the same car that started, original suspension arms, drive belts, diff pulleys, diff internals, speed controller, spur gear, pinion, hub carriers, bearings, all the turnbuckles and ball joints too, which many teams were very worried about, they even had me so paranoid I bought three packs of RPM ball joints and had two whole car sets made up ready to swap out as we needed, but they were all still on the bench at the end of the meeting, quite amazing!
At 10pm the order looked like this.
1 - DORRIS Racing
2 - DUDLEY RCC
3 - CHAND-A-COLA
4 - WORCESTER WARRIORS
5 - ESSEX MONSTERS
6 - STOKE RCMCC
7 - 24 Hour ArDon
8 - RCDisCo
9 - MMR Flux/CMC
10 - KEIGHLEY TEAM A
11 - SNOOP DOG
12 - SPC UK
13 - TEAM SPECIAL
14 - UNDER DOGS
The night session was simply awesome, seeing the light levels fall steadily from 8pm onwards and the LED lights fitted to all the cars in a variety of ways were stunning, some were subtle, some were outrageous, even dazzling, and some were just plain funny. Team Doris went for roof light clusters which changed their name to Team Mickey Mouse, but they were highly effective not only in illuminating the way forwards but also identifying their car to others as they approached; they stood out in the dark, literally shining through. Around 3am the sunrise began to pour light through the doors and roof so we weren’t running in pitch black for very long, but I’m still amazed at the pace we could hold during the night session.
By 7am the track was fully lit again and teams began to turn off their lights and faces started to appear, all be it very blurry, from sleeping bags and cars/vans and we turned to see how things had settled over night. In the grand scheme of things nothing much had happened, Doris from Dudley, but it was all about the chasing pack who were very tightly bunch with everything to play for and still 6 hours to go anything could happen!
The kit tyres were scrubbed and LRP sauce applied for as long as possible, then using a drill they were buffed against a rag to both warm and dry them before being fitted and our car was definitely one of the best handling cars in all of the wet sessions. By some pure fluke it always seemed to fall when our drift king Ben Smith was at the wheel, except the final wet stint when poor Eric was caught out and he certainly wasn’t enjoying it, so he quickly handed the transmitter over and Ben was brought back into play once again, our very own little wet Stig. When the final wet session was over Ben was on such a good pace on the now warm tyres on the scrubbed clean racing line, that we left him out there for another two battery packs and he was no slouch. This did two things, it saved another pit stop and spared our last remaining, fast deteriorating, race slick tyres for the final two hours so our best drivers Lee and Simon could finish on a strong pace.
We had 10 LiPo packs and were getting between 15 and 20 minutes run time between changes depending on driving style and grip levels, not to mention car condition and drivability! By the end of the event three packs were retired, either their life cycle was up, they had been pushed slightly too low or the constant discharge, cool, re-charge cycle had been too much for their internal structures. Even the packs that have survived will have had their life expectancy shortened for sure, 10 cycles over 24 hours is asking a lot of a battery pack, but by using only the best safety balance chargers around, the Cellpro range, and a LiPo warning system that ensured we pulled over before the batteries were completely discharged we gave them the best chance of survival.
The first team to fold, with just four hours to go, were team Stoke, after running 3rd at one point they were forced to pit for yet another rear belt change, with all axles and out drives worn right through their car was handling badly and they had tumbled down the order and decided enough was enough. In the spirit of the event they got a great round of applause from the entire paddock when the announcement came, and even though they were no longer circulating, Stoke remained in front of ‘Keighly Team A‘ until the very last half hour, which was an indication of how bad that particular team were suffering with their own very long list of dramas.
So of 15 teams entered, 14 had started after Team Ardent and Team Donny had to merge to form a complete driver line up, team “24 Hour ArDon”, which also left John and Simon time to run the meeting properly. Of these 14 teams, an impressive 13 teams finished in fine style, and the top three teams should be rightfully proud of their achievement, all making it past the 4000 lap marker, and all but two teams made it over the 3000 mark, amazing!
Team Doris were so far ahead I calculated they could pull over and rest for the last 45 minutes, and they took advantage of this fact to pull in for a rear diff change which they had been putting off just in case, but decided to put the car right rather than limping round with worn out drives ruining their pace as were several other teams for the last final hour. Team Dudley finished just 140 laps shy of the leaders, with the Worcester Warriors just 96 laps adrift of them in third. Not exactly close racing but certainly a measure of the organisation, preparation, consistency, reliability and rapid maintenance that separates the top endurance teams from the less well prepared.
|7||3||24 Hour ArDon||3732|
|13||9||Keighley Team A||2852|
Final results, photos and videos will be available to view on the Ardent Raceway web site shortly, www.ardentracing.com
So, endurance racing, would I do it again?
It was certainly an experience; I spent several weeks thinking about it, many days working on it, several track days fine tuning it and many pound notes assembling a car and spares package to cover all eventualities. I had to hand pick my team mates from the dozens that wanted to be involved, and I shortened the list after by insisting on steer wheel drivers so they could all use one transmitter and save all the messing about and potential problems binding back and forth between transmitters. I provided everything, batteries, chargers, cars etc, all they had to do was turn up and chip in. Now wonder I got such a long list of applications! It’s tough to decide whether I wanted out and out racers, or just nice guys that I could rely on to turn up and do their best for me and I’m glad to say my choice of the latter rewarded me with a very friendly and co-operative team who did their utmost to get our car to the finish in one piece. That’s what made it for me, not the result, not the spectacle, but the team work and attitude. So thanks to Ian, Ben, Lee, Simon and Eric for everything!
Would I do it again? Well not this week, I had no rest let alone sleep over 40 hours from Bed-to-Bed, I’m broken in every way possible; physically, mentally, financially. The only sit down I got was when John announced Sunday breakfast would be up and running in 20 minutes, I ran to the café, grabbed a chair and hogged pole position before the rush started, I had maybe 10 minutes sat in a chair with my eyes closed, my head reeling with ideas and potential problems, but at least my eyes had a rest. The guys and girls in the café rustled up a feast and I awoke young Callum from our car with hot chocolate and hot food, it literally saved my life and made his day!
The trip home was a mistake, I should have just sat in the car and gone to sleep, I was a hazard to myself and everyone else on the roads home, I had far too many ‘long blink’ scares and looking back I put myself and my son at risk, a silly mistake I will not make again! The picture he took with my phone while I slept half way through my dinner is priceless, and shows me just how dead tired I was.
Would I do it next year? Probably, but that depends on the formula, the chassis chosen and the rules applied. I for one would be up for a ‘no rules’ event where the motor choice and tyre choice would determine not only your speed but also your reliability, but also how often you had to stop for battery and tyre changes. The key would be the balance between pace and pit stops, price and performance, weight and durability. The choice of chassis would depend on your brand loyalty but also how well you knew that particular car to speed up repairs and increase your chance of choosing a car that would handle the run time without falling apart of wearing out important chassis and drive line components.
The real decider for me would be location, I cannot think of anywhere I’d rather do it than Ardent Raceway, an indoor race tracks is imperative, somewhere central is equally important as teams travelled from the four corners of the UK to attend, somewhere with space for 150 people or more, with camp beds, pit tables, a café and ample car parking, but above all the friendly atmosphere and professionally run operation, so congratulations to John at Ardent Raceway for organising and hosting such an excellent event. Thanks to HPI for supporting it and helping John pull it all together with support from Schumacher in form of the Sorex race tyres, and thanks to all the teams that took the opportunity to enter a team and experience what could be a once in a lifetime event.
Photos and Editorial Copyright Desawa Digital.