stock tub chassis gets warped from heat of the batteries and motor,yes the tub is fine ,but carbon fiber will not be warped due to heat.this chassis is very adjustable.the more material you remove from the stock tub,the better the chance for warping.the upper brace has very little effect on cg.batteries,motor and electronics have most effect and the motor and batteries run flush with the bottom of the chassis.if the car is designed right you should be bracing the whole car,not just the bulkheads.my brace is one piece and mounts bulkheads to chassis.what i went after with this chassis is to get the best features from all the latest touring cars and put them in the tc3