Sonoma Raceway
Sonoma, CA
Length
2.52 miles
Turns
12
Direction
Clockwise
Elevation Change
160 ft
Elevation (ASL)
150 ft
Surface
Asphalt
Grip
Good grip when clean; "green" track can be slippery first sessions
Brake Severity
High - multiple heavy braking zones (T1, T4, T7, T11)
Sound Limit
103 dB — 101-103 dB typical for HPDE (varies by organizer); Sonoma County strict enforcement
FIA Certification
FIA Grade 2 / IMSA certified
Nearest Airport
San Francisco International (SFO) - 55 miles; Oakland (OAK) - 50 miles; Sacramento (SMF) - 70 miles
Nearest Trauma Center
Santa Rosa Memorial Hospital (Level II) - 20 miles; UCSF Medical Center (Level I) - 45 miles
Track Character
Technical circuit with significant elevation changes. The Carousel (T3A) is a long, downhill, tightening left. T7 is a fast, blind uphill right. Brakes work hard going into T2 and T7. Setup for front-end grip and trail braking. The off-camber T9-T10 complex rewards a stable rear end.
“In decreasing-radius corners that are at the end of straights you are most likely to see constant-level braking and turning. This is because the more gentle arc in the first part of the corner often puts the turn-in point past the point where the road curves.”
Going Faster! — Carl Lopez (Skip Barber)
The Carousel (T3A) is a textbook decreasing-radius corner that tightens as it drops downhill. Lopez's constant-level brake-turning is the technique: maintain steady brake pressure through the initial gentle arc, then increase steering as the radius tightens toward the apex. Do not release the brakes early — the tightening radius demands continued deceleration.
“Camber angle is the inclination of the wheels looking from the front or rear of the car. Your goal in adjusting the camber angle is to maximize cornering grip by having the tire close to 0-degree camber during hard cornering.”
Ultimate Speed Secrets — Ross Bentley
The off-camber T9-T10 complex at Sonoma tilts away from the car, reducing the effective contact patch. Bentley's camber principle is amplified here: the off-camber surface pushes the outside tire toward positive camber, reducing grip exactly when you need it most. Run additional negative camber to compensate, and be patient with throttle application through the complex.
“Corner-entry speed is more important than late braking. If you update your mental picture of the corner-entry speed, to "y + 2 mph," for example, you will naturally brake a little later and not any harder. This will result in carrying more speed into the corner, and you will see tenths of a second improvement in lap time in one single corner.”
Ultimate Speed Secrets — Ross Bentley
Sonoma's 12-turn layout means small gains in corner-entry speed multiply across the lap. Bentley's mental-picture technique is especially powerful through the technical T3A-T7 complex: rather than braking later into the Carousel, visualize carrying 2 mph more entry speed. The car will naturally find the later brake point without the risk of overshooting. At a track this technical, entry speed gains in every corner compound into significant lap-time improvement.