This is a great thread...
I sold my R33 (that had nearly 200rwkw) a couple of years ago because I wanted to buy an mx5, and I can tell you that the mx5 is significantly faster (and more fun) through the corners (and you don't get that weird feeling of the 4WS shifting directions mid-corner) even dead stock. When you add a turbo it doesn't take much extra power to make it go very quick. An mx5 weighs 950-1100kgs (depending on model). An R33 weighs 1350kgs. That's why you lost...