Intake Duct.
New digital engine management.
Unlike all previous BMW Motorrad opposed-twin engines, air flows through the engine vertically on the new R 1200 GS. This has meant the inlet duct could be designed independently of the camshaft control and identical intake lengths could be attained for both cylinder sides. This vertical flow enables an optimal straight-lined intake port with equally simple chain guidance for the camshaft drive compared to the previous horizontal cylinder head flow.
With the opposed-twin engine, which is used in the new R 1200 GS for the first time, a new digital engine management system BMS-X is also used. Its main features are fully-sequential fuel injection, a compact layout and a low weight. The alpha/n-based engine management with torque interface takes into account a multitude of influencing factors. It enables easy control of torque transfer and the response characteristics assigned via the e-gas characteristics to the various driving modes to be adapted to the widest variety of boundary conditions. The basis for this management is the air quantity sucked in, which is determined indirectly via the aperture angle and the rotational speed. The engine control system forms individually coordinated values for injection quantity and ignition time using additional engine and environmental parameters (including engine temperature, air temperature, ambient air pressure) together with characteristic maps and correction functions that have been stored.
Mixture preparation is performed by electronic fuel injection via throttle bodies with an aperture width of 52 millimetres instead of the previous 50 millimetres. Newly designed, deliberately high intake air spouts and a generously sized intake silencer ensure optimal supply of cool intake air and hence optimal filling.
The throttle valves are each actuated via an electric motor in the form of an e-gas system. Driver requests are forwarded by the throttle grip sensor to the fully-electronic engine control and converted, depending on the driving mode selected, into a throttle valve target position, which is then set electronically.
The e-gas of the new BMW R 1200 GS improves drivability and optimises running smoothness in the area close to idling speed since the engine control detects any differences between the two cylinders in the medium-pressure range and compensates this by means of selective throttle valve control. As a result various throttle responses (soft, optimal, direct) are possible with the "ASC and driving modes" optional accessory depending on the relevant application area. Due to the much improved controllability, the angle of the throttle control handle could be reduced from 85 to 70 degrees. This technology could also be used with the optional cruise control comfort accessory. For the first time with a BMW GS an electronic cruise control system is therefore also available as an optional accessory for the R 1200 GS, which makes long motorway trips more comfortable too for example.
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