JPSC Forum

I've been looking at the datalog for the fastest run at NW yesterday and there are some interesting figures (at least to me)

Highest lateral G 1.257 round the cone at the bottom of the circuit.
Accel G 0.89 from the start
Brake G 0.78 (new brakes and tyres)
Highest Speed 101MPH (run down to bottom of the circuit)

0-50 4.03 (started to lift off before 60)

More ramblings about logging. It seems obvious from my fastest time that I am not transitioning from throttle to brakes fast enough. It takes me 0.8 secs to go from full acceleration to full brakes and given then North Weald has 4 big stops that is a lot of time. If I could reduce that transition from 0.8 to 0.5 then I've gained 1.2 secs (in theory). There appears to be a lot of 'undecided' time where I'm not doing anything much.....need to look again at how I drive the car.

Interesting stuff.

What datalogger have you got. I guess it is a bit fancier than a mobile phone app. When I have looked the real ones are really expensive.

Matt

I bought a Race Technology DL1 Mk2 logger....I was feeling flush at the time and it goes with the dash

jeffw wrote:There appears to be a lot of 'undecided' time where I'm not doing anything much.....need to look again at how I drive the car.

I've got a "dead time" variable set up in my logger configuration to measure just this. I just checked my fastest lap from last year at Silverstone (a lap record, no less!) and when I'm on it then the time from releasing the throttle to the brake lights coming on (which is what I'm logging) is around 0.2 seconds. So, I reckon you can be a lot faster than that.

It's certainly worth measuring as there's usually good correlation between a lap's total dead time (the DL1 allows you to measure the integral of variable) and the overall lap time.

Similarly, I've also got a "lead foot" variable which tells me how much of the lap is run at > 95% throttle. There's good correlation again there; that fast lap scored just over 55% of the lap at >95% throttle. To be honest I spend a lot of time looking at these two variables and trying to optimise them.

T

Thanks Tim. To be honest it is only when you look at the logs that you realise how much time is spent deciding what to do next lol. Which in Sprinting is dead time.