I purchased a new muffler for my Forza last week and fitted it yesterday. The G.P.R muffler is made in Italy and imported into Australia by GPS imports and sold for the very reasonable price of $499 (AU). The recommended this muffler over the Giannelli and leo vince systems, providing better sound and performance than both.
The first thing I noticed was how light it was compared to the stock, unfortunately without large enough scales I can only estimate the difference to be about 3KG’s (approx 7 pounds). The second thing I saw was the fact I could see straight through it.
Fitting was painless if a little fiddley. It’s shape and size means it’s outer edge is closer to the bike and fully under the body work. However it is a little longer and protrudes just past the back wheel. The sound is much “nicer” than the standard, however those not doing the K-Mode due to noise definitely should not get this muffler.
Riding the scooter afterwards (I did a 90Km trip suburb, freeway and backroads) the most noticeable difference came from the reduced weight. Since the muffler is part of the unsprung weight, the reduction has
made the Forza more stable during cornering. If I hit a bump now during a corner the rear dampers can now settle the bike MUCH faster. The next thing was the improvement in holding speed up hills while going 100km/h or higher (indicated), this is a real blessing for me around Canberra.
Have a look at more photos my photos of the scooter