Stage 1: Stage 1 tunes are typically just software-only. They’re best for drivers of stock vehicles who want a performance boost without any hardware modifications. Stage 2: These tunes normally require some hardware changes, like high-flow air intakes and exhaust systems, but the ROI is a significant increase in both power and torque. Stage 3: Stage 3 tunes are the most involved. They generally require extensive modifications, from turbocharger upgrades, to fuel system enhancements, and more.