2015 Dick Mayo Sprint: That Cone!

Whilst I went home with a trophy from Bristol Motor Club's Dick Mayo Sprint at Castle Combe Circuit, I didn't achieve the performance I really wanted.  The final run was a disaster with a missed shift at Quarry and then clipping the cone at Bobbies.  Despite that, the timesheets showed it was only 0.13 seconds slower, so it must have been a faster lap, but why?

I've used wheel speed to determine the start of the run and due to the low resolution of the front wheel speed sensors, there's about half a second of difference in the start times.  As a result and also because they're slightly misaligned, a pinch of salt is required here!  The green/yellow traces show the run with the cone, whilst the blue/purple is the datum run of 59.99.

The start was similar for both, but a missed shift into 2nd gear on the datum run cost 0.25 seconds before Quarry.

Start

I was earlier on the brakes into quarry on the second run, dropping 12mph before the braking point of the first timed run, but this is likely to be the offset between the two runs.  I was earlier on the brakes after the rise and harder too, but this is again likely to be offset slightly and a missed downshift left me in neutral.  I dabbed the brake before clutching to select third gear, dropping 9mph at the apex.  It cost 0.7 seconds mid-corner and this grew to 0.8 seconds down the Farm straight.

Quarry

Into The Esses and the offset again makes it tricky to see, but I was harder on the brakes on the second run and applied throttle between the apexes on the second run.  There were two stabs at the throttle on exit of the first timed run.  A huge lift into Old Paddock didn't help on the first run and the net result was 0.6 seconds won on the second timed run through this sequence.

The Esses

Coming into the final part of the lap, a higher entry speed and later braking led to a higher apex speed and 0.6 seconds gained.  Bobbies was taken in a similar manner in both runs, but the lifting of the throttle on the second run shows the moment of impact and the time lost as a result.  Without that indiscretion and the missed gear at Quarry, a 58 second run was on the cards.  Next year...

Tower

 

Here's the onboard video of that pesky cone...

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