Are rear subframe braces legal for SCCA?
 

Meant to say: Are they legal for the STR SCCA class. I think the answer is no, they are not legal. I figured I would ask though incase I've got something wrong. I'm thinking that my car fits into STR. It's got coilovers, gt3 control arms up front, spherical joints on the inside of all my coffin arms, front and rear sway bars, 17" wheels with 255 tires all around.... and a rennline rear subframe stabilizer bar.

Pedro Technobrace and Rennline rear subframe stabilizer bar both tie into the rear suspension a little below the rear toe arm.

SCCA Rules for STR:

Strut bars per Section 12 are permitted with all types of suspension,
subject to the following constraints:
1. A 2-point strut bar may be added, removed, modified, or substituted,
but only with another 2-point strut bar.
2. A triangulated (3-point) strut bar may be removed, modified, or substituted; substitution may be with either a triangulated or a 2-point
strut bar. The connection to the chassis (e.g., firewall, bulkhead)
must be in the standard location.
3. Lower suspension braces must be attached to the lower suspension
pickup point locations on the chassis within 2” (50.8mm) in any direction of the actual suspension attachment to the chassis.
4. Except for standard parts, no connections to other components are
permitted.

I think that per this wording, the technobrace and rennline brace are too far away from the 'suspension'. I'm not even sure what they count as 'suspension'. Maybe that's my problem? Does the toe arm count as suspension? I think these braces install to far away from the toe arm anyway. Maybe the sway bar counts? It's technically a spring :D.

Just classing for fun at my local non-SCCA club. So probably not that serious. I don't want to misrepresent my car when talking with others about my pax.

Toe arm is part of suspension and you are 2” from that joint, the pickup point. I would go for it.
If anyone complains, take it off.
No one will.

Reading that I would say it depends on how you interpret what a pickup point is. It's pretty far from the subframe attaching the the actual chassis, but not that far from where the inner control arms or sway bars connect to the subframe. I agree w/ above, run it, noone will likely notice.
And it's not really any performance advantage, it just keeps the subframe from collapsing under the loads produced by sticky tires, which the suspension was never designed for from the factory.