20b = fastest rotary engine (for cars) It has 3 rotors, as in your car it has 2, which means 50% more output.
I have a video of an ae86 with a 20b in it. That is a ridiculously fast, and light car. I don't know if shaggy can host videos, its pretty small, and its all japanese, so i have no clue what they;re saying, but he steps on the gas, and is gone in a second.
Anyways, heres a good link..
http://fc3spro.com/TECH/SWAP/COSMO/20b.html
And heres a link+pictures to what the car with the 20b looked like. The JC Cosmos.
http://www.mazdarotary.net/jc_cosmo.htm