T04Z's are a great turbo aren't they...i was almost going to go that route with ours. The torque curve on that graph is testament to their ability. But getting a little common now and we wanted to think outside the square as per usual. When i say "big single" im more refering to the T88, T51R, GT42 and GT45 brigade. The T04Z is more of a mid-range all rounder, and allows the owner a bit more flexibility with the usage of the car, street, circuit, drag etc. They also had the added feature of easily altering the rear housing to suit each application which is another plus for them.