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 3 Kits. Designed for motorcycles with stock or mildly modified engines using K&N individual air filters and a stock or aftermarket pipe. In most cases power increases of 10-15% can be achieved.