Variator J.Costa vs. Original Variator Virtually all big names in the world of scooter variator production base their variator design on a standard system that features cylindrical roller weights. As we all know from practical experience, the weight of the roller weights is a key variable in this system. Their behaviour is closely related to the performance of the engine: light roller weights need high rpms for the centrifugal forces (in proportion to weight) to let variator and secondary sliding sheave move apart. A shorter transmission ratio and a more powerful engine is the result. Heavy roller weights will make the variator open up at an earlier point, thus resulting in a longer transmission ratio with a smoother running engine. The new design of the variomatic by Spanish custom manufacturer J. Costa has convinced us right from the beginning. Unlike common variators, the variator itself is made from CNC machined aluminium. All the other parts that are included in delivery appeared to be of very high quality, too. The roller weights have been replaced by 14 sliding weights which move the variator along linear tracks. Admittedly, we could not help but smile at this “Ufo” at first, but this was to change soon after we took the system out for some road testing. If you take a closer look at the system, both the simplicity as well as the effectiveness of this design are impressive. The linear tracks of the sliding weights are the decisive feature in this variator system. Compared to a standard variator, the J. Costa design offers a shorter transmission ratio in the lower rev ranges (improved acceleration) and at the same time a longer transmission ratio once the sliding weights have reached their outermost point (closed primary fixed sheave). Mounting this system to our test scooter, a Vespa GTV 250cc, proved to be unproblematic and self-explanatory. When we first started the engine, we already realized the typical ringing noise which is such a common charcateristic of 4-stroke engines was completely gone! Once the first test run began, the otherwise weak GTV pushed remarkably forward. The improved throttle response at load change really put a smile on the face of our test rider. What also proved to be astonishing was the fact that the engine at once lowered its rpm when throttle was reduced. We are truly enthusiastic about this system. Original J.Costa Weight variator without roller weights (g) 374.90 423.10 Number of roller weights 6 x 11g 12 x 14.4 g Roller weights 182.00 260.00 Total weight 556.90 683.10 Starting rpm 3000.00 3200.00 Shutdown 5000.00 6000.00 Top speed 115.00 130.00 0-100 Km/h 14.5 12.63 0-100m 8.06 7.13 0-150m 10.17 9.44
Test data: Test scooter Vespa GTV 250cc, Rider weight: 90kg, Rider height: 1,99m
|Weight w/o rollers||374,90 gr||423,10 gr|
|Number of rollers||6 x 11gr.||14 x 17 gr|
|Roller weights||182 gr.||260 gr.|
|Total weight||556,90 gr.||683,10 gr.|
|Starting rpm:||3000 U/min.||3200 U/min.|
|Shutdown:||5000 U/min||6000 U/min.|
|Topspeed:||115 Km/h||130 Km/h|
|0-100 Km/h:||14,5 sec.||12,63 sec.|
|0-100m:||8,06 sec.||7,13 sec.|
|0-150m:||10,17 sec||9,44 sec.|
Conclusion: The new J. Costa variomatic with its revolutionary design is a true enrichment for the maxi scooter market. The assembly proved to be unproblematic. Top speed increase of 15 km/h, improved throttle response, better acceleration, less vibrations and reduced noise levels clearly speak for themselves, thus making this variator a very attractive choice.
German Scooter Magazine Scooter & Sport May/June 2009: " The J.Costa Variomatik (www.sip-scootershop.com) worked in the best way. We descrived the installation in detail in last issue (see article info download). The GTS 300 accelerates remarkably better and runs even faster. So far no other Tuning Variator made that possible. The measured values: Topspeed now 122,4km/h (before 120,1km/h), 0-100km/h in 13,1 S. (before 14.0 s). However the mountain valuation is most impressing, the Vespa won two seconds and flew up our test way in 47,5 s."