The SFI Spec 39.1 for Stock-Car Type Racing
Seats (Custom) has been revised to include a vent hole option in the test
procedure. If a seat manufacturer offers various vent hole configurations, an
area is specified where the manufacturer may place ventilation holes without
having to retest each and every configuration. This area of the seat back may
be left blank (all seat material removed) for testing purposes only. Upon
successful testing, the manufacturer may produce seats with various vent hole
configurations based on driver preference as long as they are within the
allowable parameters as defined in the spec. Seats with different vent hole
configurations that fall outside of the window option must still be
individually tested. The spec revision containing these changes may be viewed
here: SFI Spec 39.1