How does it work

How does a Dr. Jekill & Mr. Hyde system work?


As our name suggests, all our exhaust systems have multiple personalities.
Valve closed
The Dr. Jekill personality | Closed valve    

Dr. Jekill reflects the silent sound mode when our exhaust valve is closed, redirecting the exhaust gasses through our specifically designed exhaust chambers that not only damp the sound, but also allow a stable back pressure suitable to the engine.

Valve opened 100%
The Mr. Hyde personality | Opened valve

Mr. Hyde reveals itself once our exhaust valve is opened by a touch of a button; the exhaust flow changes from the gasses being redirected into a direct flow straight through. The exhaust chambers then reveal their primary purpose of adding acoustics to the sound in open mode.

Sound without noise
The sound that your motorcycle produces with our exhaust valve opened goes beyond that of just a straight pipe: it is a sound developed in our dedicated sound laboratory where we made sure you will have the right frequencies and the right amount of bass at your disposal once you open up your exhaust. This creates the difference between a shrill and disturbing tone qualified as “noise” and the tone that comes from a Dr. Jekill & Mr. Hyde exhaust: sound.

For those looking for the right tone at a lower volume we allow a mode in which our valve is opened 50%.

The Smartbox 2

Smartbox 2
The electronic control unit in our exhaust systems is the brain of our product. The Smartbox 2 is available for all motorcycle models equipped with canbus and is fully up to date in modern day technology. Thanks to its ability to read canbus signals coming from the motorcycle’s ECU, the Smartbox 2 makes sure you will not end up on the wrong side of the law no matter what mode you select. By committing the system to the parameters set by EU legislation, the Smartbox will seamlessly and subtly intervene if necessary. Depending on your model the Smartbox 2 will carry either Euro3 or Euro4 ready software.

The Blackbox

The Blackbox is our basic control unit and suitable for all motorcycles to 2016, both canbus and non-canbus models. Optionally the Blackbox can be equipped with a service switch that allows you to manually control the system. Pay note: this switch is not street legal and should only be used for service, racing or demonstrational purposes.

Servo Motors & Modeswitch

Servo Motors MSCH Black
By pressing the modeswitch, the Smartbox or Blackbox will send a signal to our servo motors. These will react
and position the valve in the required mode. Thanks to a dual-cable operation the servo motors can switch back and forth between the open Performance and closed Travel mode, or engage the 50% opened Dynamic mode. The servo motors are equipped with heavy duty cables and a 100% waterproof seal to ensure strong and durable adjusters.

All exhaust systems have a European type approval

All systems have type approvals and are in compliance with the legal requirements in the respective areas concerning noise levels (in stationary and riding) and emission standards.

The team from The Jekill and Hyde Company is constantly developing new systems and taking care of optimizing existing products. At the head office in the Netherlands and Germany a team of technicians and engineers is occupied with searching for the best sound and performance for your motorcycle according to the latest international regulations.

The Jekill and Hyde Company provides you with:

  • The highest quality stainless steel mufflers finished in chrome or a heat resistant black coating
  • Invisibly housed valve control inside the mufflers: placed asymmetrically which completely prevents pinching even under extreme heat
  • Cables for controlling the valves: in esthetic and technical perspective this provides the best flexible solution
  • Special stainless steel cables with Teflon coating
  • A heat resistant shell and a 100% water resistant servomotor which ensures a smooth operation.

Our product range, electronically adjustable exhaust systems and headers for: 

Brand logos

  • Harley-Davidson®
  • Indian
  • Victory
  • Honda Goldwing
  • BMW
  • KTM