> 1. The equivalent of SP would be Improved Touring, not Touring. Touring
in
> Club Racing is more like Stock.
Ah, OK. My bad.
> 2. The IT rules already restrict cages to 8 points. 6 to the floor (main
> hoop, front hoop, and two rear supports) and 2 forward to firewall (but
not
> forward to suspension). The rules also allow unlimited bars in between
> these points. Taken to extreme, this can be advantageous.
Except, of course, that you're adding weight to the car with every
additional bar and weld....
I think the number of attachment points is the performance limiter here.
Certainly 6 points is not bad. 8 is more worrisome, but the requirement to
stop at the firewall (instead of carrying the bar forward to the suspension
upper locating point, which then inevitably sprouts a cross-brace) I think
limits the damage.
Every time I go down a "let's change this rule" path, I try and figure out
ways I could manipulate the rule to provide the largest possible
performance advantage. I figure I'm as devious as anybody out there....
By welding the rear hoop supports to the tops of the rear shock towers, and
then tying the two together with a cross-brace (also welded in) I can
create the mother of all rear shock tower braces, which on a hatchback is a
big deal. I can make small improvements in bending with the door bars, but
adding any torsional stiffness requires tying the upper parts of the main
hoop to the lower parts of the opposite side front hoop, which means
passing tubes through passenger spaces a la the NASCAR "center console"
structure. Forward of the front hoop, I get nothing; even the firewall
tie-in (if it were allowed) doesn't do all that much.
So if the rules specified an IT legal cage, with a further provision that
no bars could pass through the front passenger space, I think we limit the
amount of extra rigidity that can be built in. A roll-structure-equipped
car WILL be more rigid, without question, but it will also be heavier, and
I think the stiffness/weight tradeoff tips the other way right around the
basic 6-point bar. Especially as that weight is high up in the car.
> 3. Reconciling SCCA rules with NHRA rules is next to impossible. Either
> could change at any point without input from the other body. The NHRA
rules
> for cages already disallow Autopower style bolt-in cages.
It's not that our cages are NHRA-illegal, it's that NHRA-legal cages are
SCCA-illegal. Unless there is a very good reason to to allow it, an NHRA
legal 6-point bar should be legal in SCCA autocrosses.
As I see it, the only thing stopping an NHRA legal bolted bar from being
Stock-class legal is the requirement that the rear supports be welded. A
pure bolt-in cage/bar is not NHRA legal under any circumstances, it seems.
But a welded-in NHRA 6-point bar seems entirely reasonable for SP/SM, and
with the exception of the swing-out door bars, should be IT legal as well.
Unless there is a performance advantage, building a roll structure to a
superior standard should be legal.
DG
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