What should a Vespisti consider before replacing his standard exhaust with a racing exhaust? It’s not just about optimizing performance and appearance, there are also purely legal things to consider to avoid problems.
Legal information to be considered
This information is particularly important for Germany.
- the installation of a racing exhaust results in the deletion of the operating license
- the racing exhaust must be entered in the vehicle documents so that it can be driven legally
- tampering with the standard exhaust, such as drilling it out, is a punishable offense
- Attaching false markings is also a punishable offense
- Some tuning exhausts have a parts certificate, which makes registration much easier
Important to know
The installation of a racing exhaust is an intervention in the engine electronics that requires in-depth knowledge.
Recommended racing exhausts
SIP Scootershop has a large selection and here we can be sure of getting quality. Just like with this exhaust, which promises significantly more torque, a huge increase in power, ideal gear shifting and riding comfort.
Racing Exhaust SIP ROAD 2.0
This racing exhaust fits Vespa 125 VBA-Sprint/PX80-150/PE/Lusso.
- Material: Steel, with heat-resistant black paint finish
- Special features: Suitable for wide tires, with large manifold.
- Only suitable for racing purposes, not approved by the StVZO!
db-killer
Most racing exhausts are fitted with a so-called dB-killer, which dampens the volume. This volume killer must not be removed for legal road use.
Technical modifications
A racing exhaust changes the exhaust back pressure, which has a direct effect on the scavenging of the cylinder. This in turn has an effect on the air-fuel mixture. To keep the engine running smoothly, the carburetor needs to be readjusted.
What can happen if the carburetor is not readjusted?
The mixture can either be too rich or too lean. A mixture that is too lean can lead to overheating and piston seizure. A mixture that is too rich leads to higher consumption and loss of power.
How do I recognize that the mixture is not correct?
The spark plug must be examined carefully. After riding a few kilometers with the Vespa and the newly installed racing exhaust, the spark plug should have a fawn color.
How do I achieve an optimum spark plug setting?
Starting with a larger main jet, work consistently downwards until the optimum spark plug pattern is achieved. The engine must run smoothly. Don’t forget to readjust the idle throttle screw and the idle mixture screw.
Increased performance and higher torque
A racing exhaust can achieve all of this, depending on the set-up and model.
Important to know: Because a racing exhaust is usually significantly louder than the standard exhaust, it is possible that neighbors will complain about the noise level.
Racing Exhaust SIP Road “Banana” 0237 – 0238
This racing exhaust is suitable for Vespa 90/R/SS/100/125/PV/ET3.
- The material is steel, chrome-plated.
- Special feature: with large manifold, stud bolt outlet d 52 mm.
- This racing exhaust is also not approved for use on public roads in accordance with the StVZO.
Installation
To avoid cracks in the material, the racing exhaust must be fitted without tension. Experienced Vespisti only tighten the screws lightly at first. After the final alignment of the new exhaust, the screws must be finally tightened. Nothing should drag, which means that all parts of the exhaust should have sufficient clearance. The system must also be tight. Please check carefully. After approximately 100 kilometers, please check all fastening points of the racing exhaust for tightness and retighten the screws if necessary.
Racing Exhaust SIP SERIES PORDOI
Fits Vespa GTS/GTS Super/GTV/GT 60, 125 to 300 cc i.E., 4T, LC
- Version: stainless steel, homologation
- without ABE
- We already know the saying: Not permitted for use on public roads according to StVZO.
Racing Exhaust SIP “Vintage” Replika
Fits Vespa VNA-TS/150 VBA-Sprint, PX80-150/Lusso
- Finish: black, ESD chrome (Electro Static Discharge ⇒ sudden exchange of electrical charges between two bodies, should be prevented by this color)
- Suitable for wide tires
- Double tailpipe
- No spare wheel operation possible.
- For racing purposes only. Not approved in the area of the German StVZO!
Conclusion
Fitting a racing exhaust is not just the aforementioned intervention in the engine electronics, but also in the mechanics of the engine. It must therefore be retuned, which requires extensive knowledge. If you are not confident enough to carry out this work on your two-wheeler, you should consult a specialist or have it fitted directly.
With this in mind: Have a good ride at all times!