Aeroflow Performance wastegates are especially designed to maintain set boost levels to protect your engine from overboosting. Aeroflow wastegates feature an internal valve constructed from a high temp NiCrFe based alloy. Other features include a high temperature silicone nomex reinforced actuator diaphragm and stainless steel actuator spring that delivers consistent boost pressure at high temperatures, Nitronic stainless steel is used for the valve seat, and valve bushing which all offer longer product life at extreme temperatures. Aeroflow wastegates feature water cooling ports ( 2 x M8 x 1.0mm ) for those heavy duty applications. These are optional use and can be disregarded if not required. There are also 3 lower air pressure ports and two top air pressure ports ( 5 x M10 x 1.00mm ) for easy installation this eliminates the need to rotate the actuator top, plugs are included for unused ports. Aeroflow's wastegates come preset at 1 bar. This can easily be altered by purchasing and installing springs from Aeroflow's accessory range. The wastegate also includes required stainless steel hardware for installation including: valve seat, inlet V-band clamp/flange and outlet V-Band Clamp/flange. Replacement Springs & Upgrades AF9552-1101 Inner Spring - Yellow: 6.5 PSI (0.34 BAR)AF9552-1102 Inner Spring - Green: 3.8 PSI (0.23 BAR)AF9552-1103 Middle Spring - Red: 5.0 PSI (0.31 BAR)AF9552-1104 Middle Spring - Blue: 7.2 PSI (0.45 BAR)AF9552-1105 Middle Spring - Black: 8.2 PSI (0.52 BAR)AF9552-1106 Middle Spring - White: 6.6 PSI (0.42 BAR)AF9552-1107 Outer Spring - Brown: 14.5 PSI (1 BAR)