Open Top Cars / Convertibles
To ensure the safety of all participants at our High Performance Driving Schools, open top vehicles (Cabriolet, TT Roadster, S2000, Miata, Boxster, 65 Mustang, etc) are subject to special restrictions.
Convertibles (e.g. roadsters, cabriolets, spyders) lacking rollover protection are not permitted in ACNA High Performance Driving Schools (HPDE, lapping, or any events held “at speed”). Vehicles with removable hardtops or retractable hardtops are considered to be convertibles and those lacking a rollover protection system are also not permitted at high-speed events. Targas and t-tops are not convertibles and are therefore acceptable; roof panels must be installed.
Convertibles with factory-installed rollover protection (either fixed or deployable) meet the ACNA minimum requirement for high-speed events and are acceptable, subject to approval by chapter leadership and event staff (Event Master, Registrar, Safety Steward and/or Chief Driving Instructor) and provided that vehicles with fixed protection meet the broomstick rule as stated below.
Convertibles with or without rollover protection are allowed at events where maximum speeds do not exceed 50 mph, if the activity is:
DS-Driver Skills or exercises at a driving school held in a confined area
Autocross or gymkhana events (maximum speed must be controlled/limited)
Teen clinics, safety schools, “car control clinics”
Winter driving schools, in snow or ice conditions
Driving with the soft-top up or the hard top installed is strongly recommended; otherwise, SFI and/or FIA approved arm restraint system(s) must be used and is recommended in any case. Note that this prevents the use of point-by passing signals. Full-face helmets or effective eye protection if wearing an open-face helmet is also strongly recommended.
For convertibles without factory-installed rollover protection to be allowed at ACNA highspeed events, the minimum requirements are:
A four-point roll cage consisting of a main roll bar behind the front seats with two rear-triangulated braces must be installed.
Minimum four-point harness with ASM (anti-submarining) technology must be used. Equivalent equipment (harness and seat) is required for driver and passenger – see 22.214.171.124.
Enforcement of the “broomstick rule” is required for all occupants. Minimum clearance (with helmet on) is two inches below a straight edge, placed from the top of the roll bar to the top of the windshield frame.
Appendix D – ACNA Vehicle Participation Exception List (Updated 5/30/2022)
The following convertibles do NOT have rollover protection and therefore are not acceptable at ACNA HPDE’s unless they meet the minimum requirements set out in 2.13.2:
pre-996 Porsche Cabriolet (air-cooled), Mustang, Corvette, Camaro, Firebird, Miata (all generations), Solstice, GXP, Solaris, first gen Z3’s, most British and Italian sports cars from the 40’s through the 80’s. (T Top versions of these cars are allowed.)
The following convertibles have factory rollover protection and are acceptable subject to chapter approval and provided the track allows them:
Porsche Cabriolet (996, 997), Boxster (all generations), BMW Z4, Audi TT Roadsters, A3, A4, S4, A5, S5, RS4 and RS5 Cabriolets, and R8 Spyders, VW Eos, Nissan 350/370Z roadster, BMW M3 and 3 series (1999- present), Mercedes S, SLK and CLK.
Neither list above is complete – event organizers may contact the PDEC if further guidance is needed.
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