What about a t3/t4 hybrid. Remember you are dealing with a small light car, the power to weight ratio is pretty good. Also remember that the cyl heads are a 3 valve design 2 intake 1 exhaust. You can put all the air in the chamber you want, but it has to be able to escape. Turbo's need the ability to let the exhaust escape as freely as possible, so a smaller turbo would probably by just right for us.