You don't "need" to upgrade your suspension or brakes from a legal perspective,
hey..
i don't thnik this is true..
froma legal perspective.
The 18rg was not a complied item in the ra23 celica thus meaning an engineers cert..
anymore than a ~15% power increase will means an instant brake upgrade.. it may be somthing as crappy as "get better brake pads", none the less. no one does it, but its the law.
18rg is a heavier motor, may need a front suspension upgrade, however, theres really no need.
tonnes of poeple put hot motors in cars and don't get them engineered me included.