Motorcycle dynamic exhaust system

Abstract

The present invention provides a method of operating a dynamic exhaust system of a motorcycle engine. The method includes providing a valve in the exhaust system that is movable to direct exhaust gases between a first flow path through the exhaust system and a second flow path through the exhaust system. The method includes actuating the valve at a first speed to redirect exhaust gases from the first flow path to the second flow path and actuating the valve at a second speed greater than the first speed to redirect exhaust gases from the second flow path to the first flow path.

1 . A method of operating a dynamic exhaust system of a motorcycle engine, the method comprising: 
 directing exhaust gases along a first flow path through the exhaust system to operate the engine at a first torque characteristic;    actuating a valve in the exhaust system in a crossover region of the first torque characteristic and a second torque characteristic; and    redirecting the exhaust gases from the first flow path to a second flow path through the exhaust system to operate the engine at the second torque characteristic.    
   
   
       2 . The method of  claim 1 , further comprising: 
 actuating the valve in a second crossover region of the first torque characteristic and the second torque characteristic; and    redirecting the exhaust gases from the second flow path to the first flow path to operate the engine at the first torque characteristic.    
   
   
       3 . The method of  claim 1 , wherein actuating the valve includes one of opening and closing the valve.  
   
   
       4 . The method of  claim 1 , wherein actuating the valve occurs when the engine is operating at least about 75 percent of full throttle.  
   
   
       5 . The method of  claim 1 , further comprising triggering an actuator to actuate the valve.  
   
   
       6 . The method of  claim 5 , wherein an engine control unit selectively triggers the actuator.  
   
   
       7 . The method of  claim 1 , wherein the crossover region is a range of engine speeds over which the first torque characteristic and the second torque characteristic are substantially equal.  
   
   
       8 . The method of  claim 7 , further comprising monitoring the engine speed with an engine control unit, wherein the valve is selectively actuated by the engine control unit.  
   
   
       9 . A motorcycle comprising: 
 an exhaust system defining a first flow path and a second flow path;    a valve positioned in the exhaust system, the valve operable to direct exhaust gases between the first flow path and the second flow path;    an airbox positioned remotely from the exhaust system; and    an actuator supported by the airbox and operatively coupled to the valve to move the valve between a first position, in which exhaust gases are directed along the first flow path, and a second position, in which exhaust gases are directed along the second flow path.    
   
   
       10 . The motorcycle of  claim 9 , further comprising a cable operatively coupling the actuator and the valve.  
   
   
       11 . The motorcycle of  claim 8 , further comprising an engine control unit adapted to trigger the actuator to move the valve between the first and second positions.  
   
   
       12 . The motorcycle of  claim 11 , further comprising an engine operable over a range of engine speeds, the engine exhibiting a first torque characteristic when exhaust gases are directed through the first flow path, the engine further exhibiting a second torque characteristic when exhaust gases are directed through the second flow path.  
   
   
       13 . The motorcycle of  claim 12 , wherein the engine control unit is configured to selectively trigger the actuator based on engine speed.  
   
   
       14 . The motorcycle of  claim 13 , wherein the engine control unit is configured to selectively trigger the actuator at an engine speed within a crossover region, in which the first torque characteristic is substantially equal to the second torque characteristic.  
   
   
       15 . The motorcycle of  claim 9 , wherein the exhaust system includes a muffler, and wherein the valve is located inside of the muffler.  
   
   
       16 . The motorcycle of  claim 9 , wherein the exhaust system includes a first muffler and a second muffler, wherein the valve directs exhaust gases through the first muffler along the first flow path, and wherein the valve substantially prevents exhaust gases from entering the first muffler along the second flow path.