Great White Versa wrote:
So what exactly are the purposes of these two parts?
Strut Bar
A strut bar is designed to reduce this strut tower flex by tying two parallel strut towers together. This transmits the load of each strut tower during cornering via tension and compression of the strut bar which shares the load between both towers and reduces chassis flex.
Resulting from the improved chassis rigidity (similar to that gained from a lower tie bar); may be improved steering precision under high load conditions (cornering and braking). Reduced understeer, tire wear and metal fatigue in the strut tower area may also be experienced.
Body Brace
By connecting different points of the vehicle’s frame, it successfully increased rigidity while reducing chassis flex. Under-Body Braces deliver a sharper handling and more responsive vehicle.
btw theses are not my own words just copied pasted from wiki and gtspec.