UPGRADE
you can only use a z4 with a tdo5 dont use on a tdo4 as they cant handle it apparently , i have a 94 uk wagon which come standard with tdo5 (more lag) i fitted a z4 , hks induction kit , tsl center decat , tsl group n back box and an arc dump valve much better then standard now , i would go with fitting a td05 and a z4 first but up to you