IS THREE THE MAGIC NUMBER?
Ask the average scooterist to choose anything based on name alone and I can almost guarantee the popular choice will be ‘the biggest number’. It’s reasonable logic but with SIP’s range of exhausts it pays to think a little harder. While we had access to the dyno I also took the opportunity to run a SIP 2, an exhaust that’s become the ‘gold standard’ of performance box pipes. It is not designed for this kit, but the results were more than respectable. It required no change in jetting to the SIP 3 (119 main) but still produced 15.57bhp, 1.14bhp less than the SIP 3.
As part of this experiment, I was also interested to see how the SIP 3 would perform on a standard engine. To answer that question, we gave the pipe to well-known Vespa enthusiasts Tim and Jane Lightfoot. Just before lockdown they took our SIP 3 on tour, mating it to the standard P2 lump fitted to Bella, Jane’s much-travelled Motovespa. As Tim explained, bigger is not always better…
“We used the SIP 3 on a 1200-mile round trip to the Outer Hebrides. Bella has a standard PX200E engine and for the last five years has been fitted with a SIP Road 2 so my comparisons are between the two exhausts. I believe SIP aimed the Road 3 at the kitted scoot market, and it showed. The Road 3 allows very brisk acceleration through the gears, but you need to hit peak revs before changing up. If you don’t the engine will labour and struggle to reach speed, especially in fourth gear and even more so with a headwind. When touring I’m a lazy rider and will let my speed drop as I admire a local landmark or beautiful view. If I do this with the Road 3, it really struggles to pick up speed again, meaning that I’m constantly shifting down a gear to build the revs. In terms of top speed, the Road 3 was consistent with the Road 2.
“For a fast, hard street ride or longdistance motorway use I think it’s a good, usable exhaust. For my style of back-roads touring it made for a much less pleasant ride, only performing at high revs and requiring constant gear-shifting. With a kit fitted, giving more power and a few extra hps, I expect that you could get a lot more from this exhaust. However, I couldn’t wait to get Bella back on the ramp and swap back to the SIP 2.”