there seems to be an issue regarding the hard and fast NHRA rules and the times I quoted where the last ones I'd heard. Having said that, I checked and here's what I saw. "NHRA
ROLL CAGE
Roll cage mandatory in cars running 10.99 (*6.99) or quicker or any
car exceeding 135 mph. In full-bodied cars, with unaltered firewall,
floor, and body (from firewall rearward, wheeltubs permitted),
running between 10.00 (*6.40) and 10.99 (*6.99), roll bar permitted
in place of roll cage. In convertibles running 10.99 or quicker or
exceeding 135 mph, roll cage mandatory. Cars running between
7.50 (*4.50) and 9.99 (*6.39) must have chassis recertified every
three years by NHRA and have a serialized sticker affixed to cage
before participation. Plating of chassis prohibited for all cars
manufactured after Jan. 1, 2003. Rear-engine dragsters must
conform to SFI Spec 2.7B; vehicles running 8.49 (*5.35) to 7.50
(*4.50) and/or exceeding 180 mph must meet appropriate SFI Spec
for body used. Effective Jan. 1, 2007, all new Street Roadsters must
conform to SFI Spec 10.4. Existing Street Roadsters must meet SFI
Spec 10.4 at their next scheduled recertification effective Jan. 1,
2008. No existing cars will be recertified early to delay compliance.
All others must conform to specs for body style used, as listed in
General Regulations 4:11, 10:6.
Note the difference between roll bar and roll cage as well. Draw your own conclusions from there.
