Wastegates provide a means to control the boost pressure of the turbocharged engine. Wastegates work to bypass exhaust flow from the turbine wheel. Bypassing the exhaust flow reduces the power of driving the turbine wheel to match the power required for a given boost level. Similar to the BOV, the Wastegates use boost pressure and spring force to regulate the flow bypassing the turbine.
Wastegates are bolted to the exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to improve the turbine's performance.

 

Youtube Frostbite Ram's video about SPELAB 38mm 8 PSI External Turbo Exhaust Manifold Wastegate

Details:

• Brand: SPELAB
• SKU: SP2406PP
• Weight: 2000g
• Material: Aluminum
• Color: Purple / Blue

Features:

• High Strength Cast Steel Body / Anodized Top Finish
• Fits any 38mm Turbo Manifold Wastegate Port
• Weldable Flanges for Dump Pipe / Manifold
• Barbed / Banjo Vacuum Fittings
• Easy to Change Springs with V-Band Clamped Top / Adjustable Top Screw

Package Included:

• 1 x Wastegate & Installation
• Hardware Shown in Picture

Video: https://www.youtube.com/watch?v=3_gwKF1Whsg