I think someone was pulling your leg. These things never made any HP. Back in the day, someone like Car and Driver did a car. It started out slow, ended up slow, and they suggested it was not worth the effort. It's a slug.
There are guys that swap in rotary engines, I'd expect this would make it fun.
Sounds like an Opel GT. Imported from 68 to 72 IIRC. The early ones has a 1.1 liter motor while most has the 1.9 liter motor. I had a very used a abused one back in high school along with a Opel Manta. Slow but fun to drive. Handled well and could be made to handle great. GrassRootsMotorsports did an artical on them recently also. The 240Z was a better car in most respects but the Opel had a great look that is still a classic in my mind. Thanks for the memories