Castle Combe – Sunday 27^th June

Race Report Author Jeff Davis 

Well the day started very early for this event with most people being at the school by 06:00am.  With a clear drive down to Castle Combe racing circuit in glorious sunshine breakfast was calling whilst scrutineering was underway.  With a few tweaks made to the Brian this process was soon completed but had taken longer than normal so we did not get more than ½ lap practice.

The reason for the delay was down to an unfortunate incident involving the Rotary Racing Team, one of our main rivals.  One of their drivers rolled the car on the far side of the circuit requiring the Ambulance and recovery teams to be called out.  Please to say that no injury was sustained by the driver which is more than can be said for the car.  However, the safety features of the car ensured the driver was OK being testimony to the strict rules in this area.  The down side of this was that Rotary racer was not allowed to participate further in the race (even if the car was fixed) until improvements had been made to the stability.

The F24+ race is becoming a more adopted event as the entry is rising each year.  The race is 90 minutes and after the start Zebedee and Brian took an unassailable lead being evenly matched, so much so that Brian was able to slip stream Zebedee down the final straight very closely (under 24 inches) giving rise to warnings of safety from the Marshalls.  Brian was backed off slightly and the race progressed until Zebedee, driven by Livi, crossed the line in first place quickly followed by Hannah in Brian for Second.

Not much time between the F24+ finishing and the F24 beginning so turning the cars around had to be done within 20 minutes.  Managed to do this but still had to queue up to get on the grid so staring position a bit further back than desired.   Tactics dictated that we should run for two 1 hour slots followed by a succession of 30 minute slots this reducing the effect of driver change and also giving the best fit to the new rules that the F24 event now use.  In this case the teams were not allowed to complete more than 9 laps in any, rolling, 30 minute period.  The lap times and speeds of how this was achieved is detailed in the technical section of this report.

Both Zebedee and Brian took an early lead but after a while, with Brian having to feather back slightly we surrendered 2^nd place to the new car of Maltings Academy with their car called Maltings Missile (number 41), quite aptly named as its shape was very much like a missile and a shade of matt black.  This car had a good turn of speed but towards the end of the event seemed to tail of and loose ground and eventually stopped out on the track on the last lap.

The driver line up changed from the prepared plan as it seemed the batteries of Brian and Zebedee were lasting longer than before, might be down to the new rules evening out the drain on Amps or the hot weather keeping the batteries warmer.   On the second stint Hannah M in Zebedee drove for 90 minutes whilst Beth T took Brian for 75 minutes.  Some interesting overtaking moments for both these drivers due to the uncertainty of some of the newer drivers in the other cars, plenty of use of the cars horn to ensure no collisions were made.

Brian, with its new controller, continued on smoothly keeping up a good pace to again come in second place to Zebedee.

During the race it was good to see some debutants to racing with Charlotte Peach and Beth Attwood taking the controls for the first time.  Both showed good promise for the future with smooth driving and good driving lines.  Once they get more experience they will soon make an impression on the driver line-up.

The day ended up with both cars taking the prizes for 1^st and 2^nd in each race, one of the teams best race days.

Technical View Point

Authors: - Bob Carter and Richard Kenney

The F24+ Results: -

Usage Statistics

The above graph shows the Amps drawn as Brian went round the circuit. The Drivers should be able to identify the uphill sections where high power is drawn, and the downhill sections where the current drops.

Progress Chart – Speed, Volts and Laps

This graph shows Brian’s progress through the race.  Initially the cars set off unlimited to pull out a lead, then the speed limit was varied to keep them 1/3 of a lap ahead of the number 3 car (which was YPod).  

In the last 15 minutes we experimented with the setup to ensure we knew exactly what speed limit to set so as to go at the right speed in the F24 race.

Note this was significantly faster than the F24+ pace; this was quite a slow race, as can be seen by the fact that Brian had 23/24V left in its batteries at the end.

Zebedee did exactly the same as Brian.

F24 race
 

The F24+ Results: -

For this race the speed limit set to 9 laps (1.85 miles) in 30 minutes = 33.3mph

Our main opposition, Rotary Racer, rolled their car in practice so were unfortunately unable to race.

The cars were turned round from the F24+ race with new batteries as quickly as possible to get in the queue for a good grid position; we didn’t do too badly, ending up on the 2^nd or 3^rd row. Both cars were given full power off the start line in order to clear the other cars before pulling them back to the perfect speed at the end of lap 1. Sure enough, after the 2^nd corner we were in 1^st and 2^nd position.

After a couple of laps it was clear that Brian was taking too much current to sustain that speed so it was backed off to about 30mph. Both cars then ran at essentially fixed speed until the end of the race. Maltings Missile and Rpod looked to threaten Brian at times, but the threat never materialised.

Zebedee Progress Chart – Speed, Laps, Volts, Temperature: -

Special mention has to be made of Driver #4 drive after the battery change; commitment, speed, smooth – perfect.  She has to get her head down properly when she gets in the car though!  Her lap times for 20 laps were consistent to better than 1 second; real talent!

Note: - first batteries lasted 2.25hrs so we had plenty of spare capacity. In fact they lasted 37 laps giving us a potential distance at that speed of  136.9 miles

Brian Progress Chart/span> - Speed, Laps, Volts, Temperature: -

Brian set out at 33mph (the speed limit) but this was quickly recognised as taking too many amps so we backed the speed down to 30mph, and this emptied the first batteries after 2hrs 5mins.

Unfortunately we forgot to turn the power back up after the battery change, leading to a series of slow laps.

Perfect pit stops, the timing went as planned:  3 by 1 hour stints then 2 by ½ hour stints with 61 laps completed (not 60 as GP say).

First batteries lasted 34 laps giving potential distance at that speed of 125.8mile