Thunderhill East
Willows, California · 4.61 km · 2.86 mi · counterclockwise
Thunderhill Raceway Park's East Course in Willows, California is a 4,605 m (2.86 mi) lap run counterclockwise through 16 numbered corners. Elevation spans 82.9 m to 116 m, and the layout climbs and descends enough to accumulate 60.4 m of gain per lap. The simulated speed profile splits the track into two characters. The opening third is quick: Turns 1 through 3 all carry minimums above 105 km/h (66 mph), and the fastest point of the lap arrives at Turn 9, where the model holds 144 km/h (89 mph) mid-corner after a 167 km/h (104 mph) entry. The slow work is concentrated at the Turn 6-7 complex — the lap's tightest section at a 49 km/h (31 mph) simulated minimum — and again in the closing sequence, where Turns 12-13 and 15-16 drop to 67 km/h (41 mph) and 74 km/h (46 mph). Simulated lap times range from 117.0 s on a liter bike to 122.5 s on a middleweight twin. All figures on this page are physics-simulation estimates.
All figures: physics-simulation estimates · generated 2026-07-08 · methodology & assumptions
Track outline © OpenStreetMap contributors (ODbL)
Thunderhill East — quick facts
Motorcycle track guide · simulation estimates · 2026-07-08
- Length: 4,605 m (2.86 mi), run counterclockwise
- 16 corners; elevation ranges 82.9-116 m with 60.4 m of gain per lap
- Fastest corner (simulated): Turn 9, 144 km/h (89 mph) minimum
- Slowest corners (simulated): Turns 6-7, 49 km/h (31 mph) minimum
- Simulated lap time, Supersport 600: 118.7 s at 139 km/h (87 mph) average
- Simulated lap time, liter bike: 117.0 s; middleweight twin: 122.5 s
- Longest simulated braking zone: ~153 m into the Turn 15-16 complex (liter bike)
Turn 1
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 151 km/h94 mph | 118 km/h74 mph | 147 km/h92 mph | 117 m384 ft | 92 m302 ft | +2.7 m+9 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
The lap opens with a left of roughly 92 m effective radius that climbs 2.7 m over its 147 m length. In the simulation a Supersport 600 arrives at 151 km/h (94 mph), begins braking about 117 m before the corner, and carries a 118 km/h (74 mph) minimum before running back out at 147 km/h (92 mph). Bike class changes the brake point more than the corner speed: the higher straight-line speed of a liter bike pushes the simulated brake marker out to about 168 m, while the middleweight twin needs only around 75 m and exits slightly slower at 143 km/h (89 mph). All three classes share essentially the same 118 km/h apex figure — a simulation estimate, like every number here.
Turn 2
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 148 km/h92 mph | 114 km/h71 mph | 145 km/h90 mph | 60 m197 ft | 85 m279 ft | -3.4 m-11 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 3
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 153 km/h95 mph | 106 km/h66 mph | 131 km/h81 mph | 30 m98 ft | 74 m242 ft | -4.2 m-14 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 4
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 122 km/h76 mph | 88 km/h55 mph | 119 km/h74 mph | 15 m49 ft | 51 m168 ft | +1.0 m+3 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 5
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 122 km/h76 mph | 88 km/h55 mph | 119 km/h74 mph | 15 m49 ft | 51 m168 ft | +1.0 m+3 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 6
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 141 km/h88 mph | 49 km/h31 mph | 154 km/h96 mph | 63 m207 ft | 16 m53 ft | -4.4 m-14 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 7
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 141 km/h88 mph | 49 km/h31 mph | 154 km/h96 mph | 63 m207 ft | 16 m53 ft | -4.4 m-14 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 8
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 133 km/h83 mph | 98 km/h61 mph | 134 km/h83 mph | 30 m98 ft | 63 m208 ft | +1.0 m+3 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 9
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 167 km/h104 mph | 144 km/h89 mph | 160 km/h100 mph | 27 m89 ft | 137 m449 ft | +2.2 m+7 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 10
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 147 km/h91 mph | 117 km/h73 mph | 140 km/h87 mph | 54 m177 ft | 90 m297 ft | +5.2 m+17 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 11
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 132 km/h82 mph | 95 km/h59 mph | 126 km/h78 mph | 75 m246 ft | 60 m196 ft | +3.8 m+12 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 12
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 107 km/h66 mph | 67 km/h41 mph | 124 km/h77 mph | 33 m108 ft | 29 m96 ft | -1.9 m-6 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 13
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 107 km/h66 mph | 67 km/h41 mph | 124 km/h77 mph | 33 m108 ft | 29 m96 ft | -1.9 m-6 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 14
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 146 km/h91 mph | 130 km/h81 mph | 147 km/h91 mph | 0 m0 ft | 112 m368 ft | -0.8 m-3 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
Turn 15
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 120 km/h75 mph | 74 km/h46 mph | 137 km/h85 mph | 120 m394 ft | 36 m118 ft | -4.6 m-15 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
The closing complex begins with this right-hander — 36 m effective radius, part of a 261 m double-right section that sheds 4.6 m of elevation on the way to the front straight. The simulation's braking zone here is the longest on the track: about 120 m for the 600 and roughly 153 m on the liter bike, from a 120 km/h (75 mph) entry down to a 74 km/h (46 mph) minimum; the twin needs around 87 m. Exit speed matters more here than anywhere else because the start-finish straight follows, and the model releases the complex at 137 km/h (85 mph) for the faster classes, 133 km/h (83 mph) for the twin — estimates, as throughout.
Turn 16
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 120 km/h75 mph | 74 km/h46 mph | 137 km/h85 mph | 120 m394 ft | 36 m118 ft | -4.6 m-15 ft |
Supersport 600 preset · simulation estimates · liter-bike and 650-twin figures for every corner ship in the all-access pack · how these are computed
The final corner shares its modeled section with Turn 15: two rights totaling 261 m at a 36 m effective radius, descending 4.6 m onto the main straight, with identical per-class estimates — a 74 km/h (46 mph) minimum out of a 120 km/h (75 mph) entry, and an exit of 137 km/h (85 mph) on the 600 and liter bike. Whatever speed the simulation banks here compounds down the full length of the front straight into the ~117-168 m Turn 1 brake zone, which is why the exit figure, not the minimum, is the number that shapes the modeled lap times of 117.0-122.5 s across the three classes.