Good info Mark, always interesting to read about the restricted cars, although I often feel that its fairly irrelevant a lot of the time to road tuning where you dont have that one single factor so massively dominating the performance characteristics, personally I love turbo engines that just rev and rev, my nova feels awesome at 8Krpm with nearly 2 bar of boost up it, but in a totally different way to when ive been in rally cars with a restrictor where its all over by about 5K!