Our house brand ko4s rated for 26 psi and covered by a one year unlimited mile warranty, a great entry level option for your stage 3 build. We use melett chra along with Proprietary 1 bar wastegates pre set to 9 psi for proper boost levels post tune. Unilke other brands we pre clock our ko4s for bolt on hassle free fittment. Each set also includes an install kit. Professional installation recommended.