So with our seat mounted on sliders, my helmet will NOT have 2" of space from our roll cage. The seat is also too far over to the left of center from the wheel. I propose to cut the transmission tunnel to get the space we need and weld in some 12 gauge sheet to widen the floor to allow our seat to be moved over. My only concern is yellow box section which is where the cross brace mounts under nether the car. I could maybe fab something to replace it after all is said and done. I'm kind of out of options. Just looking for feedback.

 

Done all the time in Spec Miata. You can even get pre-cut kits for it which might work well.

https://mazdaracers.com/store/produc...tch-out-panel/

 

They should just change the name to MiataRacers.com, lol

 

your complication will be the braces and brace points inside the trans tunnel. take a look under the car. cutting those won't be easy to repair. i bumped out my trans tunnel in a few places to get my seat centered without going drastic and altering the trans tunnel brace points. i don't see how many racing seats will fit in the rx8 if you're trying to get super low. i run a corbeau fx1 pro. the kirkey intermediate road race seat also looks like it would fit.