Hey this is just a question at the moment, but i was looking into doing a M54B30 inlet swap on to my M52TUC28 engine, but every time i try to find out some info the subject gets more confusing. as one person say that the ram tubes on the M54B30 are D shaped and the inlet on the M52TUC28 are oval than some one else has stated some thing completey different. so i thought i might have a look at making a custom inlet manifold, but this is my question do you need a DISA valve or can you bypass it, if so what are the pro`s and con`s or by passing the DISA valve????