For the 2017 Saloon Stock Car Technical Specifications, the following clarification relating to rear arms/wishbones will apply.
The underlying principle remains unaltered. The rear arms must remain standard. The arms can be repaired, and they can be strengthened. Modifications to rear arms that change profile/angles/dimensions etc, are not permitted.
The recommended process for repairing a rear arm, is to cut from either the top of the casing and/or the bottom of the casing (anywhere within 200mm from the centre of the bolt hole on the two front pick up points), but not through the entire arm i.e. not cutting through the original seam on either side. You are permitted to weld the rear arm. You are permitted to add additional steel to the arm to strengthen it but this must not go through the arm.
Following the repair the arm must retain its original geometry, profiles and measurements, to include but not exclusively, the original casting seam lining up.
The SSCA recognises that there are numerous arms that have been repaired by means of cutting entirely through. To facilitate these arms being used up, for 2017 the recommended process for repair noted above will apply, with the following exception, you may cut an arm entirely through (within the first 200mm from the pick up points) including the original seam
Any arm that requires repairing more than 200mm from the front pick up points will be considered not fit for purpose. The SSCA is considering allowing the repair of such arms through an official supplier in the future.
For the avoidance of doubt, the SSCA will have measuring jigs available, and drivers will be able to utilise the jigs to check repair work. The onus is on the driver to have an arm checked prior to racing, should they have doubts about it lining up to a standard arm in all respects.