Three questions

[keycom]

Ready to begin cage building here soon. My car is allowed to use 1.5" x .095" tubing. Can I (or should I) use 1.5" x .120" for the main hoop? Does the entire cage need to be the same size tubing? Does there need to be an observation hole drilled in each tube?

Is the "high density" padding required on cages this year, or just the "normal" tube padding?

I'm going with an aluminum seat. Does the seat back brace mount to the seat and the cage? Someone told me the brace cannot touch the seat itself, but instead is just a "backstop" to keep the driver protected in a rear-end contact.

Will I need an equivalent passenger seat for driver's school?




I keep perusing the GCR online, but my local club doesn't have any hard copies yet.

Thanks!

P.S. Maybe that's actually five questions. :rolleyes:

[JohnRW]

You can use .120 wall for the main hoop...but you'll have to decide if the weight difference is going to be a disadvantage. How light a shell...how much stuff you going to take off, etc.

"All tubes the same size ?" - Loaded question. The GCR is ambiguous. Some Scrutineers will tell you "All REQUIRED tubes must be the same size", others will say "ALL tubes must be the same size". Find whoever will be inspecting your car..and ask them.

Padding - the GCR seems to require the high-density padding in places where you can whack it...but I haven't parsed thru that section of the 2007 GCR yet. Somebody else chime in here ?

Seat mount - If you're using an aluminum, non-FIA-approved seat, the seat back brace needs to be fastened to the seat.

You do not need a passenger seat for an SCCA race licensing school. Nobody is crazy enough to ride along with you....

You can purchase a GCR from SCCA Merchandising...their contact info is on www.scca.com. It'll show up quickly. Get a GCR before you do ANYTHING to the car.

[abreakey]

I keep perusing the GCR online, but my local club doesn't have any hard copies yet.
[/b]

I have a spare 2007 GCR. It is still in its wrapper.

If you want to buy it from me, PM me

adamb

[Greg Amy]

John, allow me to make some corrections.

The GCR tubing size requirements for IT (GCR p89) states the "minimum tubing sizes for...all required rollcage elements." Thus, any tubes can be larger than minimum, and no non-required (alternate) tubes are subjected to this minimum. I thought we added something to the GCR to clarify that last point, but I can't find it.

Further, there is no requirement for all tubes to be the same size. If a Scrutineer insists otherwise, ask them to point out the requirement in the GCR.

As to whether or not the minimum size is adequate, that dpeends entirely on your design. However, I'll go so far as to suggest any well-deisnged age is perfectly adequate using the minimum tubing size.

In regards to rollcage padding, there was a request out there to require SFI padding on all rollcage elements subject to contact by the driver's helmet, but that was not approved. As per the 2007 GCR (p88) it is only recommended. - GA

[JohnRW]

John, allow me to make some corrections.[/b]

Feel free...I was winging it without a GCR. There's no information like bad information, huh ?



The GCR tubing size requirements for IT (GCR p89) states the "minimum tubing sizes for...all required rollcage elements." Thus, any tubes can be larger than minimum, and no non-required (alternate) tubes are subjected to this minimum. I thought we added something to the GCR to clarify that last point, but I can't find it.
[/b]

Yeah...I thought some additional clarifications were added, too. As I recall, there was conflict with the old IT language in the 17.1.4.d.10 area, where it said "Any number of additional reinforcing bars are permitted with the structure of the cage, provided they meet the minimum tubing size....blah blah blah". I know of some rally cage builders who are also SCCA Road Race Nat'l inspectors & competitors who believe in smaller additional tubing stays...and I sorta agree with them. Haven't perused the 2007 GCR yet...shame on me.




In regards to rollcage padding, there was a request out there to require SFI padding on all rollcage elements subject to contact by the driver's helmet, but that was not approved. As per the 2007 GCR (p88) it is only recommended.
[/b]

Still waiting for Confor foam to be available in pre-molded 'tubes', rather than just sheets and 'half-pipes'. Is this stuff to stiff for 'tubes' ? (i.e. will it crack ?)

[Speed Raycer]

Further, there is no requirement for all tubes to be the same size. If a Scrutineer insists otherwise, ask them to point out the requirement in the GCR.
[/b]

There is one:

9.4.1.F: (Yadda Yadda Yadda)If any of the above bend requirements cannot be met, all components of the roll cage shall be fabricated from the tubing size(s) listed for the next heavier category of automobiles.

Sounds like that rule needs attention as well... Main hoop totals 200*? You're right back to your entire cage being out of .120 wall, including the non-required bars

[Greg Amy]

I'm not sure what you're saying there; how does that require all "required tubes" be the same size?

[Roy Dean]

all components of the roll cage shall be fabricated from the tubing size(s)[/b]

I see what he's saying... If you're main hoop has more than 180° of bends (or whatever the GCR states), this rule says that ALL COMPONENTS of the roll cage shall be fabricated from the next higher required size... It should say "ALL REQUIRED COMPONENTS", but it doesn't.... It just says "ALL COMPONENTS"....

[Speed Raycer]

Thanks Dean... took me a while to get back here.