I’m planning on putting together a custom turbo setup for my 90 LS and I think I’m pretty close to understanding the basics. One question though. How do you adjust the boost on a turbo with an internal wastegate such as one coming from a DSM. Or how do you adjust boost for any wastegate for that matter. Haven’t figured this out yet.
Ther are 2 ways. One is by letting the spring in the wastegate do it. The spring is rated at a certain psi (much like a suspension spring). Once the boost pressure reaches that limit the wastegate opens and your boost is regulated. The only way to change the boost level is to change the spring in the wastegate. Using the spring alone to contol bost can lead to boost creep (the spring starts to open before it gets to the limit). The other way to control boost is with a boost controller. This overrides the spring in the wastegate and doesn’t let it “realize” boost until the boost controller lets it. For example let say you’re running 12psi and have a waste gate with a 7psi spring. You have the boost controller set at 12 psi…once the boost reaches 12psi the boost controller opens a circuit allowing the 12psi to reach the wategate and the wastegate opens.
There are 2 types of boost controllers, manual and electronic. Electronic ones are more precise, reliable, and expen$ive. Manual controllers can be some what precise, reliable, and don’t cost very much compared to an electronic unit.