I modified the typical way the horizontal forces are canceled on the RCR Superlight frame in the engine compartment.
That tubular bars that move back from the top of the roll bar cage put the vertical mounting point of the cage to the firewall at mid height. Please last photo.
This is allowing for movement in the frame at that location and is referred to as hinging. The bars on the angle moving back to the rear connection point on the rear shock towers helps but because they are angled, lateral torsion to the centerline of the car is possible and that can translate to as much a 1/16” at the clamshell to body rear cab in the longitudinal direction.
Moving these tubes anywhere does not reduce this condition but the added tube brace in longitudinal alignment with the shock tower does eliminate the movement completely, please see photos.
This is not new but is only usually addressed on a race car frame, especially a 05-06 Ford GT frames. please see photos attached.