JWR991 wrote:Where in the rules does it state the seat back support cannot be more than 6 inches from the rear bar ? The IO support look like its longer than 6 inches ?
From the rules:
3.2: Driver's Seat: Driver's seatback must reach above middle of helmet or higher. One-piece SFI- or FIA-rated competition seats very strongly encouraged. All seats must be very securely mounted to the floor or cage to avoid separation during a crash. All seatbacks must be securely attached to the seat base and braced or otherwise restrained against rearward failure.
Nick Pon's clarification from here - http://forums.24hoursoflemons.com/viewtopic.php?id=2977
"One thing to keep in mind is seatback bracing--while we don't require a fixed seatback brace, we do require something that will keep the seat from tipping rearward in an impact. On most cars, the harness bar serves that purpose--we like to see the harness bar about six inches max from the seatback.
If your range of drivers puts that distance at much more than six inches (with the shortest driver, with the seat moved all the way up), you may need to invest in an adjustable bolt-on brace like the one sold by I/O port."