Quote Originally Posted by VTi-RT
GLi is a single core, while a VTi-R is a dual core...

Weq, i believe you have a very common D-Series problem when you move to boosted power... it's called head lifted...

Lot's of D-Series owners have the same problem, heck my gf's car copped it. When running boost, the pressure causes very slight head lift which then causes cylinder pressure to leak. That's why your cooling system is over pressurising and spitting all your coolent out.... Eventually you'll see that the coolent will be pushed into the oil system causing your oil to look milky...

I recommend if you have money to get your block o-ringed and get som ARP head Studs. At the very least get a new head gasket and the ARP head studs.
Im getting it in or out of boost it happened when i installed a 2nd hand head - never happened with my old head. Ive got arps and a new headgasket but im thinking the head is warped. either way im getting another head build and going on soon.