F24+ Grid Safety

edited June 2014 in IET Formula 24+
Morning all,

First off, great work from all the F24+ teams in getting off the line at Goodwood, I was really expecting to see one or two cars not making it away.

There was however a large speed differential between the cars as they came off the line. Its pretty much a given that Dave is going to be in the lead by the end of the first lap, but the car was swamped off the line, causing a significant opportunity for a crash.

Having the cars line up on the grid in order of 'start effectiveness' would reduce the speed differential between cars during the period at the start of the race when there is the greatest opportunity for a crash. Jet & RR still have to perform the same number of overtakes as if they'd started at the front of the grid and started slowly, whilst avoiding the risk of being rammed from behind by faster starting, but likely less experienced drivers.

Basically, this grid method would reduce the net number of overtakes during the period where a crash is most likely.

Thoughts anyone?



  • How would you calculate 'fastest starting'?
    I assume a variety of methods are being used: gearing, resistors, speed controllers, and the only way to quantify it is to have an acceleration test, which would be held where? Scrutineering? With the cars on the track?

    I agree, there is a danger, and we should work to minimise it, but this one could be tricky.
  • Its a race... get over it, I am sure Dave does not need nannying by JLR!
    The tracks wide with a few little GP cars you are 16+ not 6...
    Begs the question why don't the fast cars start a bit quicker, bet they will in the next few races.. if they think its a problem that is...
  • My personal opinion is that it's not a problem, cars were started in a 3+2 grid formation so it should be reasonably easy to pass any cars that are slower off the line. I will of course continue to asses the matter, please don't forget this is the very first time we've used this type of start, it will be a bit of a learning curve for all of us. I agree with the comments on ordering cars by starting speed, it would be incredibly difficult to do. It may be that we separate grid rows even more in future.

  • Interesting question......

    If you have a PWM motor controller and make a slow start with very gradual acceleration are you saving valuable battery power, or are you wasting valuable current?
    As I understand it, a PWM controller running at half speed is using double the current.....????
  • The PWM drive can cause more current to flow in the motor than drawn from the battery. However the effective voltage across the motor during this condition is much less than the 24 V supply. The power taken from the battery and passed to the motor is essentially the same.

    Using PWM to create a soft-start and not risk blowing fuses or breakers, or stressing the mechanics is a sensible thing to do. You will be slower off the grid than others who don't use this method, but you will soon catch up. Electrical power that manifests itself as heat is proportional to the square of the current, so keeping the current lower will waste less power as heat. Motor torque is directly proportional to motor current.

    In conclusion, blasting your way off the grid using a high current might look impressive but it isn't smart.

    If you really want to improve grid safety, then cars should be grouped according to their acceleration rate. Personally I would let drivers use their skill and judgement and consume some of that adrenaline to navigate around obstacles.
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