Does a Mazda rx-7 have an LSD?

1978-1985 Generation 1 (FB/SA) [Series 1,2 and 3] RX-7s did not come with an LSD.

1986-1991 Generation 2 (FC) [Series 4 and 5] did come with LSDs on the turbo models, they differ between the series. Series 4 had a clutch type LSD, while series 5 had a viscous type.

1992-2002 Generation 3 (FD) [Series 6, 7 and 8] came with LSDs all torsion type.

Source:

http://www.allcarwiki.com/wiki/Mazda_RX-7

http://www.allcarwiki.com/wiki/Mazda_RX-7_1st_Generation_Series_1_Specifications

http://www.allcarwiki.com/wiki/Mazda_RX-7_2nd_Generation_Series_4_Specifications

http://www.allcarwiki.com/wiki/Mazda_RX-7_3rd_Generation_Series_8_Specifications