INTAKE AND EXHAUST CONTROL
AND ENGINE MANEGEMENT SYSTEM
(3) SDTV (Suzuki Dual Throttle Valve) Fuel Injection System
The new GSX-R1000 uses SDTV (Suzuki Dual Throttle Valve) system, contributing to combustion
efficiency while aiding throttle response and smoothing power delivery.
The SDTV system includes two butterfly valves in each throttle-body.
A primary butterfly valve is controlled by the rider via the throttle twist grip. The primary butterfly
valve is positioned closest to the intake valves.
A secondary butterfly valve is opened and closed by a stepping motor controlled by the ECM. The
ECM opens and closes the secondary throttle valve based on engine rpm, gear position and the
position of the primary throttle valve.
The stepping motor is directly installed on the throttle body.
The purpose of the secondary throttle valve is to maintain the air flow speed, or intake velocity,
when the primary throttle valve is opened by the rider. The primary throttle valve determines the
throttle opening, while the secondary throttle valve maintains optimum intake velocity.
The way the SDTV system works is similar to the way a CV carburetor incorporates a butterfly
valve controlled by the rider and a throttle slide controlled by intake vacuum. In providing what
may best be described as a digital CV effect, the system produces more seamless and more
linear throttle response, adding low-rpm torque as well as significantly reducing unburned
hydrocarbon exhaust emissions.
Intake and Exhaust Control and Engine Management Systems
3-7
Secondary Butterfly Valve
Primary Butterfly
Valve
2003 GSX-R1000 SDTV Fuel Injection System
