"Mr. Toad" at Laguna Seca (June 2019)"Mr. Toad" at Laguna Seca (June 2019)Open-track day with the Golden Gate Lotus Club!
 Best morning lap |
 Best afternoon lap |
On my first two track days with this car my main focus (other than dealing with rain) was managing turbo lag. This time, I spent a lot more time playing with shift points. My best laps from the morning (second session) and afternoon (seventh and last session) are illustrated above, including shift points.
I'm in 4th gear on the front straight (the white dot on each map is the start-finish line), which includes a slight cresting left turn, and then downshift to 3rd for turn 2, the Andretti Hairpin. After turn 4 I upshift for the run to turn 5, then downshift again for the moderately fast left turn. This much was a constant.
The run to turn 6 is uphill but pretty fast, over 80 MPH before braking. In Zoom-Zoom, I hit redline a second or two before braking. I experimented with upshifting to get a little more go, at the cost of a quick up-then-down shift, but never could decide which was better. In the Mazdaspeed, power falloff came much sooner so the upshift (the orange shift at the bottom of the map) was obvious.
Now it got interesting. In the morning, I'd then downshift again to maximize power through turn 6, but then had to upshift again midway up to turn 7. Heavy braking is needed for The Corkscrew (turns 8 and 8A), entered at around 35 MPH, so going back down to 3rd gear is obvious. Or so it seemed. The drop down to turn 9, probably the fastest turn on the track, meant I was again out of revs coming out of turn 9.
Turns 10 and especially 11 are obvious 3rd-gear turns in this car.
The problem at turn 9 led me to experiment with upshifting in the chute out of 8A so I was in 4th for turn 9, which then meant a quick downshift along with the braking into turn 10. That seemed to work ok other than not having an obvious place for the upshift between 8A and 9.
Next was the downshift for The Corkscrew, and that upshift from there before turn 9. Thinking about it during the break I wondered if maybe I could use gravity to buy me some initial acceleration whilst the turbocharger spun up going into 8A, then taking advantage of the low-end torque to make up for the taller gear, thus avoiding the issue of where to upshift before 9. I tried it and it worked much better than I expected.
The next area to consider was the downshift for The Corkscrew, and the upshift from there before turn 9. Thinking about it during the break I wondered if maybe I could use gravity to buy some initial acceleration whilst the turbocharger spun up going into 8A, taking advantage of the low-end torque to make up for the taller gear, thus avoiding the issue of where to upshift before 9. I tried it and it worked much better than I expected.
Finally, turn 6 is pretty fast, so I experimented with not downshifting whilst braking for it, which eliminated the upshift between 6 and 7. So long as I kept the turbocharger somewhat engaged that seemed to work. I can't tell if it was better but it didn't seem to be any worse, and less effort and clutch wasted on shifts seemed like a good thing.
All of that led to the late-afternoon pattern, with downshifts only for turn 2 (Andretti Hairpin), carried through turn 4, then again for turn 5, then finally going into turn 10 and carried through turn 11. With the low-end torque under boost it felt like it was right, even if I was in 4th for some turns which felt like they ought to have been taking in 3rd. I asked a few people who had somewhat similar cars (a Subaru WRX and a Ford Focus RS) but they were different enough that I couldn't garner any useful ideas from them.
Random other notes from the day:
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Copyright © 2019 Karl L. Swartz. All rights reserved. |
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