Dr. Jekill & Mr. Hyde - Adjustable Exhaust Systems for Harley-Davidson Motorcycles

Dr. Jekill & Mr. Hyde Electronically Adjustable Exhaust Systems. Made in the Netherlands. Covered by European & US patents.
The Jekill & Hyde Company has developed an electronically adjustable exhaust system that lets the driver choose between a stock Harley-Davidson sound,  and the world famous Harley-Davidson (louder) Rumble. The muffler contains an electronically adjustable butterfly valve. When the valve is closed,  the motorcycle produces about 85 db and gives out the same HP as  the OEM mufflers. When you open the valve you not only gain about 15 % more  horsepower, but you also get up to 130db of deep thundering sound. The  noise control is not just as a result of either blocking or unblocking the escape of exhaust gases. When the valve is closed exhaust gas is diverted through a more restrictive passage inside the muffler. When the valve is open  the muffler becomes a straight through type muffler with a resulting deeper  and louder sound. You effectively have two different mufflers within the single  muffler body. Electronically adjustable exhaust systems are produced for all Harley Davidson models from 1984 up to 2007.
The  internals of all units are 100% stainless steel. Only the highest quality materials available together with the best workmanship are used in these products which allows them to give customers  a two year full warranty on their electronically adjustable Dr Jekill & Mr Hyde exhaust system.              Installation Information
Mufflers have a universal mounting bracket that fits nearly  all H-D models. On some specific ones you only need to make a  small adjustment. Fitting advice available prior to purchase