My mate had a 500bhp rx7 drag and drift car, he got sick of rebuilding and replacing the engine every time it went bang. He just finishing off fitting his 4.0L lexus quad cam V8 with a GT500 supercharger.
The problem with rotary engine has always been the tips of the rotors, they snap off at the very first sign of det and wear badly. I don't think the rx8 lump was as bad due to carbon/diamond tipped rotors.