With new motorcycle models we expect parts to become lighter, but with one part of our motorcycle's this is not the case. For instance the exhaust system from an early 1992 Suzuki GSX-R1000 was around 9 kilograms. Today, ten years later, the exhaust system of the Suzuki GSX-R1000 is well over 10 kilograms. For some motorcycle models from other manufacturers the exhaust system even has increased more than 3 kilograms. So why is that?
With the old Suzuki GSX-R1000 exhaust system was a single-piece construction, with headers, collector pipe and silencer all welded together into one. It's much simpler than the new Suzuki GSX-R1000 exhaust system's design, which is down to the easier job it had.
While the '90s GSX-R1000 only had to silence the engine noise down to the that time standard noise limits, the latest GSX-R1000 exhaust system has to meet worldwide quieter noise regulations, as well as other exhaust gas emissions regulations. There are limits on how much hydrocarbons, nitrous oxides and carbon monoxide a motorcycle can emit, and the easiest way to reduce them is by using a catalytic converter. The catalytic converter is a honeycomb ceramic chamber, coated with rare metals like palladium, rhodium and platinum that oxidizes pollutants into carbon dioxide, water and nitrogen. This adds mass, and has to be used with a fuel injection system, preferably with an oxygen sensor in the exhaust – another complication.
Suzuki also uses an ECU-controlled valve inside the underslung silencer unit. This closes at low revs to cut noise from the motorcycle, as well as providing more optimum exhaust flow characteristics. At higher rpm, the valve opens, allowing more gas flow and noise, outside the noise regulation measuring zones.
As a result of all this, the latest Suzuki GSX-R1000's exhaust is a good amount heavier. The exhaust systems on all modern motorcycles is a rare example of 'dead' weight being added to modern motorcycle designs which doesn't improve its performance, and there's nothing Suzuki or any other manufacturer can do about it...