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. However, driveability may be compromised particularly with short stroke high RPM motors. On some modern engine and airbox designs, individual filters and proper jetting offer no performance improvement, yet compromise driveability. In such cases stage 3 kits are not available.