Is definitely the twin-turbo version on the 13B engine meant to energy the 3rd-generation RX-7 released in late 1991. Just about every rotor on 13B-REW has just one combustion chamber volume of 654cc. With two rotors, the full displacement was 1308cc. Best healthy for your Mazda swap or alternative challenge. https://mazdarx7turbo2engineforsa79787.weblogco.com/39141424/the-ultimate-guide-to-13b-turbo-for-sale