when building something over 600bhp you need something thats proven..theres no point in buying something you hope will work because believe me youl get loads of grief trying to get the power and will wonder why and im talking from experience here,i paid 1495 pounds for mine to be made to find out it wouldnt allow the turb to boost more than 2 bar and was struggling at that,then every time i went out it fell apart..now iv bitten the bullet and spent money having it redone!!it now owes me over 3k..the moral of the story..buy a proven one to start with!!cheers danny