This test follows on from the article we ran in issue 175, as a way of clearing up some of the exhaust we couldn´t manage to test that first time around. Again the testing was done at Taffspeed Racing in Newport, on their same FXR 180, which hadn´t been touched since our last test, apart from the replacement of the rear pulley wich had been robbed to fit to a customer´s machine after his had broken.

STD versus LEO VINCI TOURING

STD versus STD WITH S.I.P DOWNPIPE

Leo Vinci's Italian-made exhaust is designed as an affordable replacement for the original Piaggio system, but it comes without a downpipe. Since the original downpipe suffers very badly from rust, this does assume that it will still be worth bolting your Leo Vinci to. You should check that before buying any exhaust supplied without a downpipe. The construction is -like the original- very heavy, so it is important to make sure both exhaust bolts are fitted tightly if you don't want to risk snapping the mounting lugs off your casings. The Touring system actually looks quite nice with its re-styled heat shield, and is 'E'-marked. Despite that it was a little louder than standard and had a higher pitched note. In terms of power output, the Touring system is a little disappointing because it didn't quite match the output of the standard pipe, being around 0.5 - 0.9 hp down over most of the speed range. Even so it is the best of the non-expansion chamber exhausts that we have tested, and represents an affordable alternative to a £225 original system when the time comes around for a replacement.

We thought it was worth testing SIP's new stainless steel exhaust downpipe for the standard exhaust particularly since they claim it can raise your power output by up to 1 hp. The prototype downpipe we were supplied was a good fit, and has the obvious advantage that it won't rust - for which alone it seems worth the cost. Internally it uses the same larger bore pipe down it's full length whereas the Piaggio part has a narrower bore for the first two inches before opening out to the diameter of the SIP pipe for its remaining length. On the dyno it gave exactly the opposite of the predicted effect, and actually knocked up to 0.6 hp off the engine's power output. Oh dear. With hindesight it is naive to think that you could gain power on a standard 180 just by using a big-bore downpipe. If it were that easy, why wouldn't Piaggio have done it themselves? When we checked back to the graph SIP provided to show their findings, the engine shown makes less than 10 h p a t the rear w heel, and must therefore be a 125cc of some sort. This downpipe could feasibly improve the output of 125, but it does on a 180.