yeah mate engine cannot consume 33 psi below 5400 rpm so boost has been caped at 26 psi. its got a pair of bd14s though and the inlets only a 4x4 plenum though and head isnt ported to the max. nms call it a middle of the road head. im pondering on eec iv inlet and full head port saw someone who does it for about £1200 gns ? or something like that. should see about 530 then. do you get no surge atall then on your t4 ?