rrright! now i geddit! thanks goran. having never looked inside a wastegate I assumed that the pressure from the exhaust gas PUSHES the diaphragm open against the spring and you add boost by installing a stiffer spring i.e. 1 bar spring being stiffer then .7 bar. every days a school day!
1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going