GFB G-Force 4-Port Solenoid (Includes 4 Hosetails)If you're wanting to hold your wastegate shut longer, or wanting to extend the operating pressure range of your current wastegate spring setup, then a 4 port boost control solenoid will help you get there. A 4 port solenoid is also a better option for those who are running antilag in their vehicles. For the most part though, a 3 port is more than sufficient. For extension of operating range of wastegate set ups. Universal