What thick are they (front and rear)? And how about the JDM version, is it the same?

 

Depends on the year and model, but I believe this is right:

front: 30 mm for 93-95
rear: 19.1 mm for all 93 and 94-95 R2, 15.9mm for 94 and 95 non R2

 

The following data is for a '93 Rx7 R1, and taken right out of the Yamaguchi 3rd Gen Rx7 book.

The stock front sway bar is 1.1 inches (28.6 mm) in outer diameter. The wall thickness if 0.16 inches (4 mm).

The rear stock sway bar for the '93 R1 is 0.7 inches (17.3 mm) in outer diameter. The wall thickness is 0.1 inch (2.6 mm)

MY "New Rx7" Japanese market Rx7 brochure is written Japanese, so I can't read what the sway bar dimensions are for the different types of J-Spec FDs.

ML
MDC
www.autosportoutfitters.com/mdc/

 

Thanks guys! But it is really necessary to get a 20mm for the back then?

 

Yes, to balance out the handling, and not have too much understeer.