Regardless of which material you choose for your cage, check the rules of the sanctioning body in charge of the track where you race. In central Florida, most of the local tracks are NHRA sanctioned, so we checked the rulebook to ensure our cage met the minimum tubing thickness requirements in the rules. Generally, companies like Competition Engineering keep abreast of any rule changes, ensuring their product conforms to the latest rule revisions and will give many years of good service. Even so, we used our NHRA rulebook as a reference, along with the instructions that came with the rollcage kit, to properly install our cage. We suggest doing as we did, using the cage instructions as a reference, but installing it by the rules in the NHRA rulebook. If there is ever a question of how or where to install a bar, the rulebook should be the final authority. After all, it's an NHRA official who will be performing the technical inspection at the track, so if the cage is installed by the guidelines in the NHRA rulebook it shouldn't have any trouble passing inspection.
Even though the rules dictate how our rollcage is installed, there is still some leeway to install the cage so it best benefits the race car. By installing certain bars, like the main bar, over key areas of the unitbody frame, significant rigidity can be added to the car. A more rigid car will transfer more power to the back tires, be more consistent, and flex less, which greatly contributes to a long service life. The benefits of a rollcage aren't limited to race cars, powerful street cars will also gain rigidity and consistency with the addition of a cage.