Performance clutch kits are an important thing to have if you want to add more power to your vehicle. The simple explanation is that your factory clutch can’t “handle” performance upgrades, and so if you plan to add more power, you also need a performance clutch to handle the power. The performance clutch itself adds no horsepower, but it enables you to handle the power and is necessary if you plan to do a lot of performance modifications to your vehicle.
A lot of performance clutch manufacturers dub their clutches with a stage number (i.e. Stage 1, Stage 2, etc). Generally, Stage 1 clutch kits are good to use if you’ve got basic bolt-on performance upgrades, such as intake, header, and exhaust. The Stage 1 would be a good match for a set-up like that. It goes up the ladder, with a Stage 5 clutch generally being the highest, and being strictly for race use. You would have a hard time driving a car around town on the streets if you had a Stage 5 clutch in it.
When you install a clutch assembly, make sure the flywheel surface is extremely clean. If there is even a small amount of grease on the flywheel when you bolt the clutch assembly up to it, then you will likely have slip and need to re-install it.