Hi Rob,
I had a turbocharged 2.8 V6 powered Alpine at one time. My fabricator built it for a friend of mine originally, then he sold it to me. I had it for several years, before I sold it to my son. He had it for a few years and sold it to someone else. I don´t know where it is now.
When I got it, it still had the old Mustang II four speed in it. I swapped out the four speed and put a T5 from a 5.0 Mustang in it. I also had it tyno tuned and the shop estimated the power at 400+, since it pegged their 350 hp. pretty easily.
I don´t know if the guy that said he rode in a turbocharged Alpine was talking about mine. He would have had to have lived in So. Cal or Seattle, because that is where the car spent it´s time. Maybe the original owner gave this guy a ride. Anyway, it was fast. The dyno shop said it was the fastest accelerating street car they´d ever had in the shop. It definitely is a fun ride.
To duplicate this car, it would take a very talented fabricator, and about $6K-$7K just to do the turbo application. A cheaper way to go, and the way I would go if I were to do it again, is use nitrous oxide injection. It is way cheaper (about $1K) to do, yet is powerful. I would have a professional install it, so that it doesn´t burn down the engine, by running too lean.
Jose