2011 Rules

#61

Legal, but not the optimum placement. Cb

#62

Hi Chuck,
I think you’re overgeneralizing the overlap between SCCA and NASA cage rules. Below is the applicable NASA CCR rule. It is plainly stated that required bars must end on a plate or a mounting box, not another bar. As I said, I have direct experience with this rule being enforced this way. I have heard that some tech inspectors don’t enforce it.
I had a quick look again at the SCCA GCR and the snippet below was all I saw that is similar - probably open for interpretation as to whether “and attaching to the frame or chassis” needs to be done directly, or can be done indirectly by ending on another bar.

I do agree that the crossbars have dubious value in our cars, particularly in the rear since we don’t have coilovers.
thanks,
bruce

NASA CCR
15.6.13 Mounting Points
The roll cage shall be mounted to the floor area of the car in six, seven, or eight points.
The cage shall not go through the firewall. The seventh and eighth points must attach to
the firewall or front fender wells. All cage attachment points must be mounted to plates
or a mounting box (plinth). Each required cage bar shall terminate on a plate with a 360
degree weld to the mounting plate, except as specified in Section 15.6.14.B. There shall
be only one (1) mounting “point” per plate. This point is defined as where the “required
tube” mounts. All additional tubes mounted to that plate must be mounted as close to
the required tube as possible [Ref: (15.6.14.B)]. It is recommended that plinth boxes use
a bottom support plate in cases where the edges of the box may punch through the
sheet metal.

SCCA GCR
c. Cars must have 2 braces extending to the rear from the
main hoop and attaching to the frame or chassis. Braces
must be attached as near as possible to the top of the
main hoop (not more than 6 inches below the top), and at
an included angle of at least 30 degrees.

cwbaader wrote:

[quote]IMHO, NASA rules mirror SCCA. Either cage would be legal in SCCA since any
number of bars can be connected to a mounting plate. The fact that the down tubes
terminate at the cross bar is immaterial. The cross bar is part of the cage (blue
bars) and therefore can mount to any mounting plate with any number of bars mounted
to the same point. Note, there must be some variation allowance for access for
welding. Also note, the rear cross bar does nothing for chassis stiffness or suspension
pick up points. The cage should be mounted to the spring perches as with the other
car (and they are really a little too far rearward).

As an experiment, I installed my front strut brace with 22ga sheet metal for the last
Barber race and the ARRC. I use the curbs a lot, really a lot at RA. No deflection on the
installation what so ever. Removed the brace to save the weight over the motor. YRMV. Chuck[/quote]

#63

“Note, there must be some variation allowance for access for
welding.”

I suspect the bars are as close to the plates as welding 360 degrees allows.
My current cage has a couple of extra holes in the bulkhead to allow welding.
Chuck

#64

Steve D wrote:

[quote]kishg wrote:

[quote]wildhorsesracing wrote:

[quote]Steve D wrote:

I’ve already got the clear helium filled unobtanium ones - they are lighter and the helium lifts the front end. It’s like they aren’t even there! :laugh: :stuck_out_tongue: :silly:[/quote]

jim, don’t you want downforce not lift in the front end? :)[/quote]
Don’t confuse him. He is still trying to figure out why hot pressures of 23 won’t work.[/quote]

Ask him if he has had any luck with them @ 50psi too. :stuck_out_tongue:

#65

Does 15mm offset still work with the new track measurement method?

#66

it should - there was no intent to disallow anything that was previously allowed (just hopefully an easier method to check the track)
thanks,
bruce

turbo329is wrote: