Stage 1 Kits. Designed for motorcycles with a stock engine using the stock airbox, air filter, and stock or aftermarket pipe. Stage 1 kits are fully adjustable to allow the use of well- designed aftermarket pipes and K&N stock replacement air filters. Stage 1 kits are designed to improve throttle response and driveability.
Stage 2 Kits. Designed for motorcycles with a stock or mildly modified engine using a well- designed stock or aftermarket pipe with a modified airbox and a stock or K&N replacement air filter.