Mazda Speed 6. Manual — part 11

04 BRAKES

46

Braking System Modifi cations

Larger brakes:

Front- 12.6” (vs 11.8”) ventilated discs
Rear-12.4” (vs 10”) solid discs

ABS

Anti-lock
Braking
System

Maintains steering control by preventing wheels from
locking during braking

EBD

Electronic
Brake Force
Distribution

Prevents rear wheel lockup by maintaining optimal
distribution of braking force front to rear

BAC

Brake Assist
Control

Monitors build of brake pressure with a pressure
sensor inside the HU/CM. During hard braking it
assists braking by building additional pressure using
the ABS pump

DSC

Dynamic
Stability
Control

Monitors vehicle speed, steering angle, G-force and
Yaw and adjust braking on individual wheels to help
maintain the vehicle on the correct line through turns

TCS

Traction
Control
System

Detects drive wheel spin and maintains traction
by cutting engine torque or applying braking to the
slipping wheel

ABS and EBD have been around and BAC is simple to understand. However, DSC
and TCS are relatively new so we will cover these functions in detail.

With DSC and TCS, the HU/CM determines the direction the vehicle is headed
and reduces engine torque and applies the brakes individually to keep the vehicle
moving in the correct direction.

•

04 BRAKES

47

DSC
DSC is designed to help correct understeer and oversteer.

Understeer
Is described by drivers as plowing or pushing. Understeer occurs when the vehicle
moves further to the outside of a turn than the driver intended and the driver must
slow the vehicle and increase the steering angle to correct the vehicle direction.

Oversteer
Is described by drivers as fi shtailing or spinning out. Oversteer occurs when
the vehicle moves further to the inside of a turn than the driver intended and the
driver must slow the vehicle and decrease the steering angle to correct the vehicle
direction.

Direction of travel is determined by inputs from the steering angle sensor and the
combined sensor. The combined sensor measures yaw angle, and forward and
lateral G-forces.

Yaw Angle = the angle of a vehicle’s travel compared to its heading angle.

Heading Angle = angle by which the longitudinal axis of a moving vehicle
deviates from its true direction of travel.

•

•

04 BRAKES

48

↕

Forward G-force

↔

Lateral G-force

Yaw Angle

04 BRAKES

49

Combined Sensor
All combined sensor readings (yaw, forward and lateral G-force) read 2.5 volts
while the vehicle is at rest. The voltage of each sensor in the combined sensor will
increase or decrease as the direction of vehicle travel changes.