Set me straight on the cage

[jimgood]

I have read many posts over the years about people having to modify or redesign the Coupe cage for racing. This gave me the impression that the cage, as shipped from FFR, does not comply with SCCA or NASA rules. I have never heard any details as to what or why things were changed.

I was just watching the video of Dave presenting the changes to the latest Coupe kit and it looks to me like the cage would comply, but it's hard to tell for sure. If I had to venture a guess, it would be that the only thing missing are door bars and anti-intrusion plates.

So, is that all that's needed or are people making other changes to comply with competition rules? Are people making changes in order to beef up the cage?

[Jacob McCrea]

Jim,
I too have read a few posts on the other forum stating that the as-delivered Coupe frame does not meet SCCA or NASA rules due to the lack of door bars. My own review of those rules confirmed those statements.
I started a thread on this forum which chronicles my frame mods. As I read those two sets of rules, the cross-bars I've added (so far) are not required by the rules. I added them nevertheless because I can't resist the urge to customize the cage a little. They surely add a little strength, but also add weight to the back of a car which is already heavier in the back. I'm content to take the good with the bad.
I am presently figuring out how I'll add the door bars without requiring extensive mods to either the fiberglass door jamb area or the interior aluminum paneling. I also need to avoid running a bar too close to my head. As for the anti-intrusion plates, it sounds like I need to take another look at the rules and see if I overlooked something.
I have to add this caveat: I would not take anything I say about those rules as the last word. Those rules, and tube chassis design in general, are far from my area of expertise, and I am not a SCCA or NASA official. I would think that consulting an official tech inspector would be the safest way to proceed. I will likely do so before finishing the door bars.
Also, if anyone has modified their Coupe to include additional protection for the fuel cell, I would be grateful if you would share some pictures or insights into what was done, and why. When I compare pictures of the regular Roadster frame and the Challenge Car frame, the latter looks like it has a more substantial structure protecting the fuel cell. I've reviewed the SCCA rules for this requirement and haven't found clear guidance. I hope this helps.

[Jim Schenck]

Jim,

The cage that's there is a good start and nothing would have to be modified or removed but door bars would have to be added to at least meet the minimum requirements. The two forward bars to the front X and the fuel cell protection tubes are also additions made to the challenge cars that should be considered for a road race coupe as well. Depending on how fast a car is being built there is plenty of room to add things like halo bracing and a petty bar which not only make it safer but stiffer as well.

[jimgood]

Thanks for the replies. I don't know where I got the requirement for the anti-intrusion plates on the door bars. I just searched the NASA CCR again and didn't see that requirement. Maybe it's in a class rule somewhere.

[Hankl]

Guys,

For some clarification, here is a excerpt from the SCCA rules for side protection,

From Improved Touring



G. Side Protection: (2) side tubes connecting the front and rear hoops across both door openings are mandatory. Door side tubes may extend into the door. NASCAR-style side protection, or one bar bisecting another to form an “X” is permitted. The door window glass, window operating mechanism, inner door trim panel, armrest, map pockets, and inside door latch/lock operating mechanism may be removed and the inner door structural panel may be modified, but not removed to facilitate this type of side protection. The stock side impact beam and the outside door latch/lock operating mechanism shall not be removed or modified.

H. Mounting Plates: 1. Each mounting plate shall be at least .080 thick if welded and
3/16” thick (with appropriate backing plates) if bolted. There shall be a minimum of three (3) bolts per mounting plate if bolted.
2. Each mounting plate shall not be greater than 100 square inches and shall be no greater than twelve (12) inches or less than two (2) inches on a side.
3. Whenever possible, mounting plates shall extend onto a vertical section of the structure (such as a rocker box).
4. The mounting plate may be multi-angled but must not exceed these dimensions in a flat plane.
5. Any number of tubes may attach to the plate or each other.

I. Hardware (Bolts) All hardware shall be Grade 5 or better. 5/16” minimum diameter.

J. In order to provide a secure seat back support a section of tubing equal to the roll bar shall be installed horizontally from the main hoop upright to the diagonal brace. This tube shall be no higher than shoulder height.

And this from the "GT" Section,



C. Side Protection - Open and Closed Automobiles 1. The minimum side protection shall consist of a side tube
connecting the front and rear hoops across both the door open- ings. Additionally, there shall also be either a diagonal tube from the front hoop to the rear hoop bisecting the door opening below the horizontal side tube, or not less than two (2) hori- zontal side tubes. Additional tubing may be added. NASCAR- style door bars are recommended.

If you build to either of these rules, you should be within the rules for all sanctioning bodies, BUT, you should always check with your local "Tech" people at the track, while constructing the cage to make sure. So as I read it, the "X" bars are a option, but the "Nascar" type configuration is preferred from a safety standpoint, which I totally agree with.

Hank :cool: