Hi Tom,
Welcome to the RC390 forum!
I am most intrigued by your RX7. I have a 2004 RX8. Sadly, no turbo. We're thinking it needs a supercharger.
Those rotary engines are cool right up until they blow up! Ours made a most distressing noise and quit last Summer. One factory rebuilt engine installed at the dealer and we are back in business.
Cheers!
~Kam