Well with 440-450rwhp an RX7 should be in the high 10s. That can be done with a 60-1, or T04B. With a T04S, you can make more power so it should be fairly easily attainable with a strong engine. I know people make 500+ with a T78, and figure they can make closer to 600. With 600 you should be able to get in the 9s. I'm not saying anything for sure, but with a proper setup and tuned right.

My car? Its a disgrace since I have a little low compression. I should be able to get into the 12s, and I just have a hybrid turbo that runs out of breath.