Thunderhill East
Willows, California · 4.60 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 85 km/h (53 mph), and the fastest point of the lap arrives at Turn 9, where the model holds 118 km/h (73 mph) mid-corner after a 174 km/h (108 mph) entry. The slow work is concentrated at the Turn 6-7 complex — an 82 km/h (51 mph) simulated minimum — and again in the closing sequence, where Turns 12-13 and 15-16 drop to 72 km/h (45 mph) and, at the lap's tightest corner, 53 km/h (33 mph). Simulated lap times range from 126.3 s on a liter bike to 130 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, 118 km/h (73 mph) minimum
- Slowest corner (simulated): Turn 15, 53 km/h (33 mph) minimum
- Simulated lap time, Supersport 600: 127.0 s at 129 km/h (80 mph) average
- Simulated lap time, liter bike: 126.3 s; middleweight twin: 130 s
- Longest simulated braking zone: ~87 m into Turn 7 (liter bike)
Turn 1
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 126 km/h78 mph | 110 km/h69 mph | 129 km/h80 mph | 42 m138 ft | 80 m264 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
Turn 2
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 117 km/h73 mph | 86 km/h53 mph | 139 km/h86 mph | 6 m20 ft | 49 m159 ft | +1.7 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 3
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 122 km/h76 mph | 93 km/h58 mph | 120 km/h75 mph | 33 m108 ft | 57 m188 ft | -4.0 m-13 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 |
|---|---|---|---|---|---|
| 109 km/h67 mph | 102 km/h63 mph | 106 km/h66 mph | 18 m59 ft | 68 m223 ft | -0.5 m-2 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 |
|---|---|---|---|---|---|
| 108 km/h67 mph | 104 km/h65 mph | 116 km/h72 mph | 45 m148 ft | 71 m234 ft | +1.7 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 6
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 146 km/h91 mph | 83 km/h52 mph | 97 km/h60 mph | 0 m0 ft | 46 m151 ft | +6.8 m+22 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 |
|---|---|---|---|---|---|
| 93 km/h58 mph | 82 km/h51 mph | 129 km/h80 mph | 87 m285 ft | 44 m146 ft | -12.1 m-40 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 right-hand half of the 6-7 switchback runs tighter than its partner — 44 m effective radius within the shared 276 m, net 5.3 m-descending section — and carries its own simulation estimates: 87 m of braking, an 82 km/h (51 mph) minimum, and a climb back to 129 km/h (80 mph) at the exit for the faster classes. Engine output separates the bike classes only modestly here in the model. The middleweight twin arrives at the same 82 km/h (51 mph) and gives up a couple of km/h at the exit, yet every class shares the identical apex speed because the corner radius, not power, sets the floor.
Turn 8
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 140 km/h87 mph | 92 km/h57 mph | 128 km/h79 mph | 15 m49 ft | 56 m185 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 |
|---|---|---|---|---|---|
| 174 km/h108 mph | 118 km/h73 mph | 129 km/h80 mph | 12 m39 ft | 92 m300 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 10
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 134 km/h83 mph | 105 km/h65 mph | 120 km/h75 mph | 51 m167 ft | 74 m241 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 |
|---|---|---|---|---|---|
| 146 km/h91 mph | 102 km/h64 mph | 132 km/h82 mph | 60 m197 ft | 69 m226 ft | +4.1 m+13 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
Still climbing — 4.1 m of gain over 129 m — Turn 11 tightens to a 69 m effective radius left. The simulated braking zone is disproportionately long for the speed involved: 60 m on the 600 and a full 75 m on the liter bike, from an entry of 146 km/h (91 mph) down to a 102 km/h (63 mph) minimum. The twin manages with 33 m. Exit builds back to 132 km/h (82 mph), or 131 km/h (81 mph) on the twin. Together with Turn 10 this corner caps the sustained uphill stretch on the back half of the lap; from here the elevation trace begins working its way back down toward the finish.
Turn 12
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 93 km/h58 mph | 72 km/h45 mph | 107 km/h67 mph | 42 m138 ft | 34 m112 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 13
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 104 km/h65 mph | 86 km/h54 mph | 105 km/h65 mph | 54 m177 ft | 49 m161 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
The right-hand counterpart to Turn 12 completes the direction change, and in the physics model it carries its own set of estimates: a 49 m effective radius inside the 165 m, gently descending complex, a 104 km/h (65 mph) entry, 54 m of braking, and an 86 km/h (53 mph) floor. Every class posts the same minimum here — radius-limited corners equalize the field in the simulation — and the differences only reappear on the drive out, where the 600 and liter bike edge the twin's 105 km/h (65 mph) by under a km/h. The left-right flip means the modeled line treats 12 and 13 as a linked S-shaped event rather than fully independent corners.
Turn 14
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 117 km/h73 mph | 115 km/h71 mph | 138 km/h86 mph | 45 m148 ft | 87 m285 ft | -0.7 m-2 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 |
|---|---|---|---|---|---|
| 118 km/h73 mph | 53 km/h33 mph | 122 km/h76 mph | 51 m167 ft | 19 m61 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 16
| Entry | Min | Exit | Brake start | Eff. radius | Elev Δ |
|---|---|---|---|---|---|
| 122 km/h76 mph | 104 km/h65 mph | 118 km/h74 mph | 15 m49 ft | 71 m233 ft | -1.2 m-4 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