I drove an RX8 and a 350 Z last week and was impressed by their chassis rigidity. They flexed very little even under hard cornering. How can I improve the rigidity of the 3rd gen (without breaking the bank)?? I understand the RX8 chassis is twice as stiff as the RX7.

 

I installed a bolt in roll bar and there was a big difference in how the car rode and drove. It really helped the chassis and even reduce some noise in the back.

 

Some of those Mazdaspeed (I think they make some) or AUTO-EXE (I think I got the name right ) chassis stiffeners might help, too.

-Max

 

Do they make and "sub-frame connectors" for the car, like they do for the old muscle cars? I guess that's what Max suggested, chassis stiffeners. Otherwise it's a roll bar/cage. It would really block your rear view, but the best way to improve torsional stiffness is with diagonal bars. If you install a roll hoop, run the rear bars from the top corners of the hoop down to the opposite side strut top... making an X in the rear.
Good luck

 

Anyone have any experience with the mazdaspeed style stiffeners?? Are they worht $700?

 

Best chassis stiffener available is a 6 point cage.