Quote:
Originally Posted by aerohead
At least one production motorcycle incorporated a 'smart' muffler which had a computer-controlled butterfly valve inside.
The motorcycle engine underwent a full-spectrum dynamometer test to evaluate it's best performance at all rpm's as a function of exhaust back-pressure,then a look-up menu was burned into the ROM chip which allowed the computer to modulate a servo motor linked to the muffler's valve; enabling the engine to always remain in the sweet-spot.
If you've got a loose $100,000 you want to throw at a chassis dyno,you'd be able to do this to your car.  |
My grandpa's 1999 yamaha r1 had an exhaust butterfly valve, but I doubt it was computer controlled as the thing had carbs. Although it did have a MIL system that had codes for the exhaust valve, so it could be.