Beeblebrox JBC: 2nd Shakedown at Puckapunyal – And Then There Were Two


Progress has been made over the previous shakedown/practice session from in November 2019 as the team got two karts out on track for the first time. With minimal traffic on circuit and almost perfect weather conditions, a solid amount of laps was able to be in by both karts. Due to running old set/s of tyres, getting the rubber up to temperature was problematic. Both karts had spins while on fast laps, finding the limits of grip of these old sets of tyres. At the end of practice, each had completed 50 or so timed laps with the fastest laps for the day being 54.84s for the Monaco (42) and 56.42s for the EA Racing OTK (74).

#74 EA Racing Hardrock OTK, with Torini Clubmaxx 4 stroke engine, in the braking zone, about to go through the bus stop at the Hume International Raceway circuit, Puckapunyal.
#74 EA Racing Hardrock attacking the bus stop at Puckapunyal.

How the day went down

What a difference a few months can make. After the disaster that was the first outing and shakedown at Puckapunyal circuit, hopes were high that this time out would be better and, lucky for us, they were.

Preparation was stepped up prior to making the hour long trip up the highway so that all bases were covered especially in those areas which fell short, causing grief on the first outing. The advantage to having so many things go wrong the last time is it gives plenty of room for improvement and lessons to be learnt. 

One of those important lessons learnt was not to do major works on the engine and/or drive train in the pits. On that day (of the first shake down), having run out of time the night before, I was attempting to mount the engine onto the chassis of the OTK (74) optimistic that it could be with basic hand tools in the pits. How wrong I was and the kart didn’t end up running at all instead spending the whole practice day on the stand back in the paddock.

#74 EA Racing Hardrock with Torini 4 stroke on the out grid ready for a run at the Hume International Raceway circuit, Puckapunyal.
#74 EA Racing Hardrock with Torini Clubmaxx 4 stroke, on the circuit out grid about to go on a run.

As the Christmas and New Years break was between these first and second practice days, time was particularly limited and as I had other commitments during this few week period, I didn’t have the time to mount the engine myself. Instead the decision was made to have it sent off to the local karting workshop, leaving it to the experts to work their magic and getting the engine fitted by the required date. By outsourcing this task it guaranteed that two karts would be ready for this second practice day and sure enough come Thursday afternoon (the day before practice day), two karts were ready for track action. Having two running karts ready for a day at the track was something that seemed so far off, almost impossible, only a month or two prior.

Another noticeable change between this outing and previous (also learnt from prior headaches and frustrations), we now had our own trailer to transport one of the two karts. On the previous occasion, I had borrowed a work colleagues trailer and this proved to be problematic as it was a size that wasn’t suitable for hauling a go kart down the highway. In the interim, was able to find a decent flattop trailer which suited the needs of transportation much better. While the party van still didn’t have a tow bar installed on the day, there was no problem towing the trailer with the Hilux, the aim is that by the next practice day the party van should have this fitted. Next time out (hopefully) there will be no need to take two cars rather only van with trailer in tow.

#42 Monaco on the Harbor Freight Easy folding trailer at the Hume International Raceway circuit, Puckapunyal. #74 EA Racing Hardrock OTK fitted with Torini Clubmaxx 4 stroke engine, in background having just been unloaded from the Toyota Hiace "party van"
#42 Monaco on the trailer at the circuit. #74 EA Racing in background having just been unloaded from the party van

The weather was almost perfect even with the occasional cloud cover, threat of heavy rain from the South West and a constant strong breeze blowing across the track, the temperature otherwise stayed a pleasant and consistent 22ish degrees and during occasional burst of sun shine through the clouds the track temperature would welcomely increase.

This practice day was being held on a Friday, as a result there was only a hand full of drivers actually in the paddock, around twenty or so, and only four or five of those out on track at any given time. As time out on circuit was golden and needing to really learn the track, this was an opportunity to get a bucket load of laps in, which at the end of the day ended up being around 50 timed laps for each kart.

Tyres were the only real issue and only because neither of the karts had a full matching set. The number 42 Monaco had Maxxis on the front and MG red whites on the rear, while the number 74 EA Racing had Vegas on the front and Maxxis on the rear. Some of these tyres were old, really old, some sets (like the MG’s) had been sitting in my workshop for the best part of 3 years prior to being used today. This hodge-podge of tyre selection was purely an attempt to just put some sort of rubber onto the karts and get them out onto track, not ideal in the least and hand an impact on balance and handling. For the next outing (all going to plan) there will be newer, less shit, uniformed tyres for both the karts.

Tyres were the main issue for todays practice day. Finding a set that wasn't thrashed that could be used on the karts was a mission. Picture shown is of a used Vega hard compound tyre on the #42 Monaco. Obviously this was changed before heading out onto the track for the first run. The rear set was replaced with a used set of MG red whites on the rear only with the fronts remaining that used Maxxis mediums.
Left rear on the #42 Monaco. These used Vegas (hard compound) on the rear were replaced by another used set of MG red whites.

In total, each kart had 5 runs of approx. 10 timed laps each run, there were spins and visits to the gravel trap as the old dead tyres were really being pushed as hard as they could possibly could be. This will be an easy enough problem to solve for future – put less shit tyres on. For the next practice day I would imagine both the Monaco and EA Racing will have a full set of Vega’s (control tyre for 4ss class), whether they be used or brand new is yet to be confirmed.     

Monaco GP5 (#42)

The #42 Monaco GP5 with Torini 4 stroke on the stand in the pits. Pictured just before heading for the first run on the track at the Hume International Raceway Puckapunyal.
#42 Monaco GP5 on the stand in the pits, just before heading out on track first run of the day.

Best lap: 54.84s

The improvement of the Monaco from its previous outing was substantial. There were differences in the set up of the kart which accounted for this dramatic improvement compared to the shakedown in November. Probably the most substantial difference was how the engine was being mounted, being mounted further forward and lower down on the chassis. Along with the new engine mounting position there was also a smaller sprocket on being used, better suited to the long straights of the Puckapunyal circuit. These setup changes resulted in a best lap time of 54.84s, 2 seconds better than the previous best lap time for this kart.

As the Monaco was running an old (who knows how old), thrashed set of MG red whites, the rear of the kart felt limited not gripping anywhere near as much as it should. With a change in tyre pressures and increasing track temperatures, the grip level did improve by a small amount but still remained the weakest part on the kart by far. Although, even as the track rubbered in there was still occasions when pushing the limits of grip on these far from new tyres was just too much for the worn rubber, resulting in a number of spins through-out the day including a biggish one at the end of the main straight going into turn one, after a moment of snap oversteer resulted in the kart facing the wrong way in the kitty litter.

  • #42 Monaco, Torini Clubmaxx 4 stroke engine, about to have a spin in turn 1, Hume International Raceway, Puckapunyal
  • #42 Monaco, Torini Clubmaxx 4 stroke engine, facing the wrong way in turn 1, Hume International Raceway, Puckapunyal
  • #42 Monaco, Torini Clubmaxx 4 stroke engine, off the track at turn 1, Hume International Raceway, Puckapunyal
  • #42 Monaco, Torini Clubmaxx 4 stroke engine, off the track and in the kitty litter at turn 1, Hume International Raceway, Puckapunyal

Despite this, five solid runs were able to be put down with approx. 50 timed laps for the day over the course of about 4 hours. Only minor changes were made to the set up during the day, mainly related to tyre pressures as getting temperature into the tyres (especially the rears) as this was the biggest issue to overcome. Once temperatures increased, balance of the kart started feeling okay.

Tyres and spins aside, it was a productive day for the number 42. No mechanical issues to speak of and even with the couple of spins and off track excursions into the gravel trap there was no damage. Getting the kart to this base level was a really important milestone, now there is something to build upon, practising to get closer to race readiness in a few months time.

EA Racing OTK (#74)

#74 EA Racing Hardrock OTK with Torini Clubmaxx 4 stroke engine, about to leave the out grid on the first run of the day at the Hume International Raceway circuit, Puckapunyal.
#74 EA Racing about to leave the out grid and go out on track for the first run of the day.

Best lap: 56.42s

Finally the OTK was out on track! Having missed the November practice/shakedown day, it was a small victory to be putting in laps, getting a feel for the track and working on setup.

As with the Monaco, there was a mix-match of tyres on the kart front to rear (Vegas on the front and Maxxis on the rear) and will have undoubtedly affected the handling and balance in someway. From driver feed back, GoPro footage and my own observations behind while out on track, the rear didn’t have enough grip for the track conditions, tending to break traction in higher speed corners. There were occasions when the kart looked like it should have been competing in formula D, going around corners in a controlled drift.

Much of these same balance and handling issues came out of tyre temperatures with the first few runs being hampered by the tyres not getting up to temperature. It wasn’t until almost the third run and a few tyre pressure adjustments that they final came good and started to give something resembling grip. As with the Monaco, because of the age, wear and unknown history of a set of used tyres, it was an up hill battle to get the temperatures right and therefore consistently quick times.

Being the very first time out for this kart (and driver) a mid 56 second lap was to be expected. This time is almost identical to that of the first time out for the Monaco, by that logic expect better times over the next few practice days, especially once a better set of tyres is actually on the kart.

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