fishie, If you don't want yr eng. to burst in to flames :-) then don't over boost. So change the CT20 & bov if you want.
(The 225 is not equip with the map sensor, so if your BOV blows the pressure back to the pre-turbine pipe it would be better)
(The 225 is not equip with the map sensor, so if your BOV blows the pressure back to the pre-turbine pipe it would be better)