2021 Blue Book. Section “K” Page 172. Regulation 2.2.1
This rule has been incorporated to bring the seat mounting requirements in line with the FIA approved system.
The following section explains the correct installation procedure for seat supports.
It is intended for new build vehicles only. It may however also apply to owners applying for a renewal of their Competition Car Log Book for the new style passport. This will be down to the discretion of the authorised inspecting Motor Sport U/K scrutineer.
The new seat support regulation is described below:
2.2.1. Supports must be attached to the shell/chassis via at least 4 mounting points per seat using bolts with a minimum diameter of 8mm and counterplates, according to drawing No. K32 or K64.
In the case of drawing No. K64 the end plates may alternatively be welded to the counterplate.
The minimum area of contact between support, shell/chassis and counterplate is 40 sq cm for each mounting point.
In Series Production Cars manufacturers’ standard seat mounting points may be used.
If quick release systems are used, they must be capable of withstanding vertical and horizontal forces of 18000N, applied non-simultaneously.
If rails for adjusting the seat are used, they must be those originally supplied with the homologated car or with the seat.
For new build vehicles from 1st January 2021, where transverse seat mounting rails are used, they must be compliant with drawing no K64 or homologated by the FIA or an FIA recognised ASN. In the case of drawing no K64 the end plates may alternatively be welded to the counter plate.
The following is the approved alternative method of installation.
“A” The U shaped extruded section is permitted to be attached local to the seat mounting contact area. It is not required to be the full length of the crossmember.
“B” The Mounting Re-enforcing plates may alternatively be welded to the bodyshell.
The Cross member End Plate is permitted to be welded to the re-enforcing plate as opposed to being bolted in position.