Yeah they come with multiple springs. I ended up with the 5lb springs in mine. It all depends how you route your exhaust into the Gate. I teed off and most that do that can get about 12-14PSI boost out of a 5lb spring. If you mount the gate in the stream of the exhaust flow at an angle then the springs should work as they are labeled. I do have an Electronic Boost Controller that tees into the lines so I can fine tune it a lil better.
