Tuesday, May 05, 2009

HPR Analysis

Here is a track map and speed/distance chart of a 30 Min session at HPR in the M3. I'm actually quite proud of this session as I was focused on carrying more speed into corners and clear improvments are shown in the data.

This was my first session on Nittos and the average lateral G for the session was .2 G higher than a similer session on Kuhmo MXs a month earlier. It was cold and blustery -- 45-50 degrees F and overcast.

Segment 1

Turn 1 is a fast, flat 60 mph left and the end of the second longest straight. The apex is slightly obstructed by the pit wall on entry. On the first laps I was slowing to 57.4 mph, over the next 7 laps that increased to 61.5 Mph. Minimum speed is directly related to exit speed, so this is worth 3/10th in this segment but will also help in the next segment.

Segment 2

Turn two is a 180 degree sweeper and there is a 3-2 downshift under braking and a 2-3 up shift 100 ft after track-out. I've tried the whole thing in third and the data shows that the shift is worth 1/10 in the ~10 second segment.

Segment 3

Turn three is a little kink leading onto the straight and the most important corner on the track.

This is a corner that is easy to overdrive, it is tempting to carry a bunch of speed in, but the really fast way is to be really smooth in and get in the throttle before the apex. There was a 5/10 improvement from lap 2 through lap 7 and an increase in minimum speed from 60.4 mph to 65.8 mph. Unfortunately there is not a total correlation between the highest minimum speed (at the apex of 3) and the highest maximum speed (at the exit of the segment). There is correlation between the highest minimum speed and and the shortest time for the segment.

Segment 4

Segment 4 is the end of the back straight, a slightly uphill right hand 90 with a slightly blind apex. As you can see from the speed/distance chart I am braking later and slowing less with each lap. It's really all about not slowing down too much.

Segment 7

This is a high speed, steeply uphill sweeper that falls away near the top. To is easily one of the most entertaining corners on the track.

What is shown in the middle of the segment is less and less braking at entry. Notice how the speed conserved early is carried all the way to the end of the segment.

Faster in is faster out here -- the more speed you can carry in, the more speed you retain climbing the hill. There is a 5/10th sec and almost 3 mph difference between the best and worst.

Segment 9

Another entertaining corner, downhill, off-camber, with risky run-off. Again the speed/distance chart shows slowing less and less each lap.

In summary, the data shows a consistent improvement, taking little bites, and the reward is better laps.

From Lap 2 (2:13.57) to Lap 8 (2:12.45) there is a 1.1 sec reduction in lap time. The Traqmate claims the Theoretical Best lap (combining all the best segments into a single lap is 2:10.05, So I have plenty of room to improve consistency.

Here is a friction circle for the same session. Notice how accelleration is grouped -- the strongest (in second gear) is shown by a dark line near the bottom of the chart, third gear acceleration is shown by the darker line above.

This indicates that this is a HP limited car, since it can accelerate near the max and turn near the max at the same time. It also shows that this is a clockwise track because the left side is darker than the right.

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