Interesting info, from the FAQ:
The stock suspension for the BJ Proteg can be roughly categorized into 4
groups: Normal, Hard, Sport and MP3/MSP.
The “Normal” suspension has been used only on cars bound for Asian/Pacific
countries. It uses softer springs, no rear sway bar, and a smaller front sway bar
than U.S.-market cars (the actual diameter of this swaybar has not been verified).
The small front swaybar from this model may be useful to reduce understeer for
competition in SCCA Solo II Stock-class competition. Other than this swaybar,
parts from this suspension are probably of little use to U.S. and Canadian
enthusiasts.
The “Hard” suspension uses a 20mm front swaybar and a 16mm rear swaybar
for the 1999-2000 cars. The front swaybar has been increased to 21mm in
2001, possibly to increase understeer "safety" handling. This suspension has
been used on DX & LX U.S. and Canadian-market BJ Protegs. Some models
use different lengths of springs to keep the ride height uniform between cars with
different combinations of optional equipment. However, the spring rates are
always the same; the only difference is the length. The “Sport” suspension has been used on various European, Japanese,
Asian/Pacific 323 and the 2001+ ES and P5. It uses slightly stiffer (by ~15%
than "hard") springs and struts than the “Normal” suspension. The front sway bar
is also larger (22mm) and the rear sway bar is 17mm. The front sway bar has
been increased to 23mm in mid 2002, probably also to increase understeer
"safety" handling. Ride height maybe slightly lower than the “Hard” suspension.
The MP3 suspension uses stiffer springs (10% stiffer than "sport") that lower the
car by about 15mm, a front strut tower brace, stiffer Tokico struts, and larger
swaybars- 25mm front, 19mm rear. Parts from this suspension may be used to
upgrade lesser Protegs; however, the swaybar endlinks on a BJ Proteg attach
to the struts, and the MP3 uses stronger brackets to accommodate the stiffer
swaybars (see Racing Beat's
site for more information). If you use MP3 sway
bars without the matching MP3 struts, be prepared to reinforce the strut brackets.
The MazdaSpeed Proteg's suspension design is based off of the MP3's suspen-
sion. It uses even more stiffer springs and Tokico struts. Because the suspension
design is based off of the MP3, the problems mentioned above also were inherited.
