Injuneer

Time to upgrade from a roll "bar" to a certified roll "cage". Some of the requirements are unclear:

For a roll "bar", per Sect. 16 General Regulations 4:10 "All roll bars must... extend in height at least 3" above the driver's helmet with the driver in normal driving position......"

For a roll "cage", 4:11, Full-Bodied Cars, I do not see any mention of minimum requirement for height above helmet. Does the 3" requirement still apply?

If the 3" requirement still applies, how do you achieve this in a 4th Gen F-Body? A friend of mine has his certified, and they enforced the 3" requirement. But his car was a convertible. In order to meet the 3" requirement, he had to bolt the seat directly to the floor, and "slouch" a lot. And, the convertible seemed to have a little more room height-wise for the hoop.

My hoop is already within 1/2" of the headliner. My helmet actually sticks up into the t-top cut-out. I know I can gain about 1" by deleting the "slider" under my Corbeau seat. How tough were they on the height requirement when tech'd for certification? Did anyone ever check the requirement later on in "tech"?

Van

Fred,

When I was measured, with me sitting in a stock power adjustable Firebird seat, I didn't have three inches between my helmet and t-top. The tech guy measured the distance the hoop was away from my head not directly above my head. The main hoop passes above and behind my head, not directly over. I've never seen an f-body cage that didn't have the main hoop oriented in this manner.

I was told that it must be "above", as in higher than the drivers head, and at least three inches away with the helmet on, but that the hoop did not have to pass directly over the drivers helmet.

My inspector was more **** about the swingout having a legal joint and lock and that the side bar passed to my left beween my hip and shoulder.

Injuneer

I understand that "3" above the driver's helmet" doesn't mean directly above the helmet. My current hoop is pretty much to the limit of the "no more than 6" behind the driver's helmet" requirement. I was interpretting the 3" above the drivers helmet to indicate that the top of the hoop, and the top of the halo sidebar had to be 3" higher than the helmet.

Maybe the best way to do it is to take it to a shop that routinely builds SFI-rated chassis and cages and let them figure it out. When the roll bar was installed by Matt Antonelli at Finsh Line Performance in NJ, I told him to take into consideration the future requirements for "cage" conversion. Unfortunately Matt has left NJ to work for Roush Racing..... so I need to find another shop.

Thanks.

Stephen 87 IROC

I don't have an interior and my main hoop is pushed as high as it will go without actually removing the roof. My race seat sits lower than a stock seat and I know I don't have the 3" clearance. I'm not at a stage where I need a chassis certification and tech has never bothered me about the height.

There's only so much you can do in a full body car. You can't force the driver to sit on the floor because then he couldn't see over the dash.

Thomash

When I had my cage certified there was no interior in the car. I did not want to have a problem and have to remove everything. The inspector checked to see the welds were good and went all the way around each joint. He checked the tubing diameter with a pair of calipers and checked tube thickness with a ultrasoninc gage. Point of interest: There were tube chassis cars there that were just the cage and frame(no body or suspension). The inspector got up on the flat bed truck checked it quick and stuck a certification sticker on it. The whole process takes five minutes.

Injuneer

Thanks for the feedback.