Intended for motorcycles with a stock or mildly tuned engine using a well designed aftermarket pipe with a modified airbox and a stock replacement air filter. Stage 2 kits are designed for applications where individual filters cannot be installed and for applications where airbox modification improves the engine's performance. In most cases power increases of approximately 8% can be achieved.
Intended for motorcycles with stock or mildly tuned engines using a well designed aftermarket pipe and individual air filters. 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.