The FIA Form of recognition for the Dolomite Sprint (#5542) shows the first amendment (2/2v) for a Group 2 homologation was from 1-4-76.
However the recognition form doesn't show the exhaust. This is because Article 260 of Appendix J to the International Sporting Code 1971 (and 1975) states:
- e) Engine-exhaust manifold, piping and mufflers: free. Yet, for events run
on open roads, the efficiency of the mufflers must remain, in all cases, within the
limits specified in the police regulations of the country of the event.
Do the French federation state why they don't accept the FIA rules of the day?
As an aside, the Group 2 Ford Escort RS1800 was re-homologated in 1977 as the Group 4 Escort RS. Apparently this was because it required far less production: 400 instead of 1000. But it seems Ford only made 58 in 1974-5 and another 50 in 1977. Graham Robson claims Ford successfully argued that there enough cars made by third parties (which would have needed 2ltr, alloy block, BDA {BDG} engines to count), but the FIA rules are explicit in that cars had to be for sale to individual purchasers through the normal commercial channels of the manufacturer. FIA did allow Group 4 variants and evolutions on 50 cars, e.g. Chevette HSR and Porsche 924 GTS, but the Escort was a fresh approval.
Cars were transferred from Group 2 to Group 4 in 1975-7 as part of the leave that allowed components homologated under Article 260 (banned from 1976) to be used until the end of 1977.
Graham