Vehicles that are already equipped with factory turbochargers have engines with large potential for power that cannot be fully obtained by using the original turbocharger(s). Big gains can be found by upgrading the exhaust, intake, blow-off valve and intercooler and adding more fuel and boost, but by also replacing the stock turbocharger with a properly sized GReddy turbo upgrade kit, you can experience new levels of power. Depending on application, kits will either bolt onto factory manifolds with integral wastegates or use hand-made SUS manifolds with external wastegates