I recall there were a couple of after market suppliers of hop-up parts for the Kadett. A buddy owned one of these “full race” Kadetts in Iowa City. It would turn 7,000 rpm and make a sound like a hoard of killer bees.
You want to hear a hoard of killer bees listen to a rotary Mazda go down the track @ 12,000 - 14,000 rpm’s. I am a v/8 guy but the rotary is crazy.