The World Karting Association has recently completed a review of the “ladder system” within the WKA Mazda / Bridgestone Manufacturers Cup Series. This review identified performance inconsistencies among the Sportsman, Junior and Senior classes.
The speed increase for the Sportsman drivers advancing to the Yamaha and Komet Junior classes has been too great. However, when the Junior drivers move to Yamaha and Komet Senior, lap times have been slower due to the added weight for the classes with no proportional increase in power.
Based on several months of monitoring and deliberation and a test session held Monday, September 17 at New Castle Motorsports Park, the World Karting Association Trustees approved several technical changes to the Yamaha and Komet Junior and Senior engine specifications to balance the performance across the Sportsman, Junior and Senior classes.
These changes will be effective at the 2013 season-opening Man Cup Sprint Championships this December 27-30 at Daytona International Speedway:
1. Yamaha and Komet Junior classes will use a special WKA filter cup that will reduce the air volume and thus restrict performance. Testing has shown this is a low-cost method for performance reduction and only requires installation of the cup and leaner carburetor settings. The filter cups will be available for purchase at the WKA office and at the Manufacturers Cup events. A number of kart shops and engine providers will also carry the filter cups.
2. The Yamaha Senior class will use a new tuned exhaust system, the RLV Y-SR. This system is similar in design to the models used on the KPV engines and will offer a higher level of performance over the four-hole can without raising the engine RPM’s. The length will be run at 8½” minimum head pipe length. This system includes the RLV #9110 straight header and a 1.75” straight connector tube.
A secondary benefit of this change is that the high levels of engine heat generated by the four-hole can will be reduced thus extending the life of the engines between rebuilds.
A similar exhaust system will also be introduced for the Junior Yamaha classes in 2014 after further development work is complemented.
Other notable changes for the 2013 competition year include:
- The Komet Senior class will be re-named “Komet Pro” and will use the KPV 2 pipe currently used in the Junior class. This will allow drivers moving up from the Junior ranks to compete by simply removing the restricted air filter cup. The pipe will be run at the current 10" Senior class minimum length.
- For 2012 participants in the Komet Senior classes, a special pipe exchange program is being offered by the KPV importer, Haddock, Ltd. Inc., for any senior driver needing to replace their current 4 pipe to comply with the new rule. To be eligible for this program, a driver must be one of the 23 competitors shown in the point standings for the 2012 season in the Komet Lite and Komet Heavy classes.
- The new Komet Pro class will run for the normal Man Cup awards as well as an additional cash prize package for each event and for the season's points series. More information on this new program will be available soon.
- The Leopard-only Senior class, formerly known as Parilla Leopard, will now be titled Parilla Senior and will include the Leopard and X30 engines at 365 pounds minimum weight.
A WKA’s Pit Board announcement will be released once the WKA filter cups become available for purchase.