COmpressing the braking zone
Above I have selected Racer 5's best three laps which did not have any major anomalies. There are two graphs above; the first is the speed graph showing the drivers speed as a function of distance and the second is the lap comparison graph. The lap comparison graph plots time against distance traveled. This is a very helpful graph as it makes it very easy to identify were the most gains can be found. The faster a line moves away from the reference line (that is the flat line, in this case the red one) the more time is being lost in the lap.
There are four points of interest that we will dig into below. First we will look at the three significant spikes in the lap comparison graph. Once we establish what is happening in these corners we will look to see how this is effecting the straights that follow; specifically the one tag with the no.4
Points of Interest 1, 2, & 3
Compressing the braking zone
In the second two turns shown above I have indicated when each of the racers have begun to decelerate. Notice the wide distance between the two lines in each graph. In the middle graph the distance is nearly 50' and in the third graph that distance, as measure in RaceStudio, is 112'!
Now take a look at the middle graph above or look at the graph below, same sector just zoomed in. Notice how the slop of the speed lines change towards the end of the braking zone? (blue arrow below) Braking was completed early, Racer 5 is releasing the brake peddle and coasting to turn in. The shallow deceleration slop in the pink line is particularly bad. If the Racer 5 would move his braking point closer to the turn he would extend the proceeding straight and reduce his time at reduced speed. Not only would this improve his lap times but it would reduce his susceptibility to being passed.
Maximize mid corner speed
Studying the minimum speed in each of these turns we find Racer 5 is any where from 2 to 5 mph slower than what the chassis and tires are capable of giving on this particular day. Maintaining mid corner speed without sacrificing exit drive is essential bring down lap times.
Point of interest 4
But slow in makes for fast out right?
Yes it does... generally. In looking at our final point of interest (no.4 in the first graphic) we see how Racer 5 does generate a better drive out of the hairpin (turn 8) than the reference racer. Both the green and the pink lines have descending comparison lines after acceleration begins as highlighted by the red arrows. When considering the entire sequence as a whole (braking, turn in, apex, track out, and the following straight) we see the gains made by exit drive do not make up for losses before apex. The pink line has a net loss of .346 seconds despite carrying an extra 4 mph down the entire straight. The straight is simply not long enough to make up for what was lost in the braking zone.
Action item:
- Compress the braking zone. If you feel your self coasting between braking zone and turn in you can move your braking zone closer to the turn. Take small bites if you need to.
A big thank you to E Racing for providing me this data and the racers that recorded these laps. Also thank you to Scott Knott for being my sounding board on this analysis; your thoughts where helpful! This was a fun data set to play with as I have never raced at Barber and it served me as good proof of concept for what we are hoping to provide with this site.