IF you were using OEM or OEM replacement then you most likely exceeded the limits of that unit. Their not built to hold up to racing conditions so why expect it to last?

Do a search for Mini Stock racing. Many racers use the Ford 2.3L engine for that type racing and most likely have found a clutch that will hold up to racing conditions.
You should use a sprung clutch but with more or stiffer springs and stronger construction of the clutch plate itself.

My friends and I trashed a new Center Force HP street clutch disc autocrossing the car. We ripped the disc apart leaving only the sprung hub when we took it apart. Sent it back to Center Force and got a very strong disc back for free. Never had a problem with it after that.