The problem with this `traditional' approach to scooter tuning is that it relies on the original exhaust system being fairly poor in terms of outright performance. The performance of those fitted as standard on older scooters or restricted machines, can often be significantly improved upon by the application of a specially designed expansion chamber. The thing with the Runner 180 engine is that is is not restricted to comply with any law other than emissions and noise legislation and thanks to sophisticated computer-aided exhaust design technology, the original exhaust is very efficient. We know from the experimentation of British tuners such as PM Tuning and Taffspeed, that trying to build a pipe that would out-perform the original exhaust was no easy matter. Paul from PM Tuning admitted that after building a huge number of unsatisfactory prototypes he came close to giving up, before he found something that gave a worthwhile improvement. All this made us very suspicious about the many foreign exhausts appearing on the British market. Had the manufacturers put in the same evelopment effort as Paul, or were many of them simply trying to sell pipes that are really for the 125cc Piaggio machines and don't neccessarily work on the 180? The only way tofind out was to get as many as possible together and hold a big dyno shoot-out. Hey Presto, what have we here.

THE TEST

Taffspeed were chosen as a suitable venue for the test; Not only could they supply many of the test systems from stock, but also because they had a bog. standard Mk1Runner180 on which to try them. All the pipes were tested on the same machine on the same day. No modifications were made to the machine unless stipulated by the manufacturer. Each time an exhaust was fitted the engine was accelerated from 20 mph to 90mph several times until a consistent curve was produced. Once we were happy that the transmission and exhaust were at working temperature, the scooter was run at full-throttle from standstill to over 80 mph. The resulting graphs therefore Show the power output of the engine compared to road speed. Most standard machines with less miles under their belts (sic) put out between 16and 17 hp, but this figure tends to me after a few thousand miles, the basic performance of our test machine was actually very healthy, with a smooth flattopped curve that touched a peak output of 17.2 hp at the rear wheel.

STD versus POLINI

STD versus KUNDO

Like the Zirri pipe, Polini´s lightweight system works at
higher engine revs than the original, which means lighter
transmission rollers are needed to make the best use
of the power. None are supplied with the exhaust,
so you would need to buy them separately and find a
correct setting by trial and error. While the
Polini pipe still makes less peak horsepower than
the standard pipe, because of it´ s revvy nature
it would feel better at top speed if left on
standard transmission settings.All the way up to
68 mph the standard exhaust is significantly
better, but after that point the Polini
pipe carries on making power while the
standard one drops off. At 78 mph the
Polini pipe is 4 hp up on the standard,
but this extra top end performance
is not worth the trade-off in reduced
acceleration. While the Polini pipe may
work better with some form of kit and
tuning, on a standard engine it is
not worth trying.

V.E Spares are distributing these as a V.E.
Race Expansion suitable to fit all the
Piaggio 125/150/180 two stroke engined
scooters. Made in Spain, they don't look
or sound too bad. In terms of power spread
then the Kundo is remarkably similar to the
standard exhaust, so no transmission
modifications are required. Even so,
it doesn't manage to match the output
of the original, and remains around
1 to 1.3 hp down through the whole
speed range, apart from a microscopic
benefit beyond 70 mph. The main
advantage of the Kundo pipe is that
it costs £70 less than an original
system while looking and sounding
more sporty. Given that it will
make a 180 Runner go slower
though, it´ s probably better to
spend a bit extra on
something that works.