Very high performance race exhaust with an especially wide power-band suitable for everyday use.
Where a four-stroke motor requires valves, camshaft, exhaust and a turbo, a two-stroke just requires a well designed exhaust. A few pieces of sheet-metal modelled to create a form that harmonises perfectly with the layout and size of the openings in the cylinders bore, known as transfer and exhaust ports. The design of the resonance chamber not only influences the removal of hot exhaust gases, but the pulse effect also affects the flow of fresh fuel mixture into the cylinder. On modern two-strokes this technology is the main reason for its superiority over the four-stroke motor.
As simple as the description may seem, the creation of a properly formed expansion chamber body is a science for itself. This is where the wheat is separated from the chaff. Really good exhaust fabricators are as rare as uncooked steak and often only maintain limited production runs, making their products usually expensive.
NORDSPEED, based near Bremen in northern Germany, enjoy an almost legendary reputation as far as the production of excellent race exhausts for vintage geared Vespa and Lambretta scooters is concerned.
The systems created by Tobi Rüßmann for the 200cc Vespa largeframe models represent an absolute benchmark in the world of exhaust manufacture. The limited space between the cylinder studs that leave the transfer ports with a restricted amount of air to breathe is his area of speciality and the design of his exhausts makes the best out of this unusual motor layout.
SIP and NORDSPEED have combined their efforts in this field and the result are exhaust systems with the most powerful design, coupled with modern features such as EGT and a lambda sensor connection possibility.
Technical specifications of all SIP by NORDSPEED exhaust systems :
- O-ring flange, suitable for all common cylinders.
- EGT connector.
- Lambda sensor connector.
- Flange plate allows the attachment of most common silencers.
R/T 25:
The R/T 25 is an extremely torquey exhaust which still has a nice wide powerband. That makes it much nicer to ride on the road than a pure “torque pipe”. Despite it gets into the powerband early the peak power possible is among the best to be had from this type of engine.
The R/T 25 works best on an engine with the suitable environment. In plain English that’s a adequately large carburettor, a gas-flowed inlet port and, of course, a tuning kit with larger area ports.
The R/T 25 also works well on a Quattrini M232/244 barrel.
The exhaust is made with 1.2mm and 1.5 steel thickness, which helps to keep the noise down
Attention: The R/T 25 does not fit with a mainstand without modifications.
The R/T 25 requires the following port times on the barrel used to work as intended:
- Transfer ports: 130°-138°
- Exhaust port: 188°-198°
Conclusion: the perfect pipe for a properly powerful daily-ride-engine, gets on the pipe early with a wide powerband and an excellent balance of torque and power.
SIP- TIP : A well set up carburettor and ignition are essential for a reliable motor. Tools such as a strobe lamp (#FS118600) and a degree disc (#83002000) are available in the SIP shop. The jets for the carburettor set up should be from the same reputable manufacturer, as numerous producers work with different manufacturing tolerances. We recommend the purchase of a jetting kit from either SIP or KMT.
