eB2 4 Port solenoid from Turbosmart Turbosmart eB2 4-port Solenoid 4-port boost-control solenoid for the boost control of dual port wastegates Is required for the electric dual port boost pressure control 4-channel solenoid for boost pressure control in turbo engines. In contrast to 3-channel solenoids, this 4-channel solenoid can be used for dual chamber boost pressure control. This enables an even more precise and efficient boost pressure control. A setup using a 10-psi wastegate spring could be controlled to deliver 10 to 50-plus psi when a four -port solenoid is used. This additional pressure on the top of the diaphragm helps to keep the wastegate or actuator from lifting its valve to bleed off pre-turbine exhaust. This is a great solution on high-powered FWD cars. With the much better control for the solenoid, the boost level can be set low enough to limit wheel spin at lower speeds and cranked up to higher levels to maximize traction at higher speeds. maximum control of the boost curve maximum boost pressure from a particular turbocharger Suitable for e.g. e-Boost2 and e-Boost Street