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wbjones HalfDork
12/31/09 1:52 p.m.

can we assume that he will then bolt it to the car ? if not you have blown you ST eligibility

MattP New Reader
12/31/09 3:08 p.m.

ST inherits the stock class allowance in 13.2.H:

H. Roll bars and roll cages may be added (See Appendix C). It is strongly recommended that roll cages be constructed according to the GCR, though they must be bolted (not welded) into the automobile and be contained within the driver/passenger compartment. Roll bars may be welded in. A roll cage has more than four attachment points to the body or frame, or has bracing both fore and aft of the main hoop.

Weld-in bars are TOTALLY LEGAL in Stock and any category that inherits its allowances (ST, SP, SM).

Cages, however, must be bolt-in in Stock and ST. SP and SM allow weld-in cages.

MattP New Reader
12/31/09 3:21 p.m.

In reply to MattP:

Oh, and I see the rule that is confusing in Appendix C:

In the case of cars with unitized or frameless construction, mounting plates may be used to secure the roll bar structure to the floor of the car. The important consideration is that the load be distributed over as large an area as possible. A backup plate of equal size and thickness must be used on the opposite side of the panel with the plates through-bolted together.

This is a really confusing way of wording it. What it means is that if the mounting plate is bolted, a backing plate must be used.

Jensenman SuperDork
12/31/09 8:55 p.m.

My biggest concern with the standard 'bolt in' rollbars is that the 'feet' are, if you look closely, sharp around the edges making it work like a can opener when enough force is applied in the right (wrong?) direction. If using such a thing, I would at least 'chamfer' the edges of the 'feet' to make it harder for the foot to slice through the 20 gauge sheet steel. i would much prefer a big ol' flat plate to spread the load.

$750 is a good deal for what you describe.

P71 GRM+ Memberand SuperDork
12/31/09 9:26 p.m.

Going over the 2009 GCR, I have to agree with MattP and the cage maker that weld-in rollbars are acceptable for STS/STR.

I'm scheduling it for late January, should take 3-4 days. His shop is right by PIR as well, which is nice. The only question I still have left (unless the GCR changes tomorrow drastically) is what kind of belts to get since he doesn't recommend removable horizontal bars for safety reasons (which I can agree with).

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