I just ordered a fully divided turbo manifold with dual wastegate runners. I'll be running dual Tial 38mm's, but I am a little confused on which springs I need to run in both. Will both wastegates see the total amount of boost (~23 psi), therefore needing the larger springs, or will both wastegates see only half the boost (~12 psi), needing only the smaller spring?

 

Try the single turbo section for better answers.