2002 Blue Book. Section “K” Page 162. 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 primarily intended for new build vehicles only. It may also apply to vehicles applying for a renewal of their competition Car Logbook 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.
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.
The following statement has been issued by Motorsport UK in the April edition of the Scrutineers Bulletin.
Motorsport U/K are receiving a high number of queries regarding the regulations for transverse seat mount bars, which have been published in the 2020 Yearbook in (K)2.2.1 (and Drawing No.64).
We are aware there could be a large number of cars with existing Vehicle Passports/CCLBs that have potentially smaller diameter cross members, or other methods of mounting (weld on tabs, captive nuts etc.)
This is despite the fact that the regulations have never permitted these types of mounting, the Blue Book only ever having detailed a direct to floor mounting.
Naturally we are not expecting all vehicles to immediately change their mounts.
The discretion of the inspecting Scrutineer should be exercised, providing the mounts presented do not appear to be causing a hazard or are not fit for purpose intended..
However, new build cars should certainly adopt the current regulations and existing competitor should be encouraged to comply at the earliest opportunity.