group 4 FiA and tubular exhaust manifold

[dololo]

hello , i am guessing about making a group 4 car , but the french federation refuses a tubular exhaust manifold , except if i can prove thzt it was used in competition

If some of you have old pictures of rally cars where we can see this sort of manifold (on dolomite or tr7 sprint ) , i would be grateful for sharing


have a nice weekend

Laurent

[xvivalve]

All TR7 Sprints had a tubular exhaust manifold as the standard item apparently won't fit. However, conversely, the TR7 Sprint tubular manifold won't fit into a Dolomite engine bay.

Ken Clarke is your man for this sort of information 'Dolly Racer 33' on here...

[soe8m]

Was it ever homologated as a group 4? You can only drive in group 4 with a group 2 dolomite sprint homolgation but why would you do that?

Jeroen

[Graham.Fountain]

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

[soe8m]

I think ford did homologate to gp4 to continue with the same car. Staying in gp2 meant downsizing and almost back to normal like leafsprings and angled shocks again. Triumph wasn't bothered and didn't homologate any and had all in gp1 after 1977.

Iirc you have use appendix J from 1981 for historic rallying.

Jeroen.

[Graham.Fountain]

Appendix J 1981 says for exhaust manifolds:

• f) Engine-exhaust system and elements: Free. The piping will however be
  conceived in such a way as to end on one of the sides or at the rear of the car.
  However, for all types of events, organisers may provide for a particular
  restriction, which will be mentioned in the regulations of the event. Besides, for
  events run on open roads, the efficiency of the mufflers must conform to the
  legal prescriptions of the country where the event is run.

As to Ford and the MkIII Escort, the differences between what was allowed for Group 2 and Group 4 were minimal. The article in 1975 covering modifications for Group 4 said:

• Modifications authorized: exactly the same as those authorized
  for Group 2-Special Touring cars (see Art. 260).

NB: One of the few times they managed to spell a word with the -ize suffix correctly. Mostly the mispelled them as -ise, what the OED called "the special French spelling", as H. W. Fowler quoted in Modern English Usage.

Appendix J 1976 added some weight limit differences, but the main difference remaind in the number of cars needed, 400 not 1000 from 1976.

So Ford's reasons for moving the Mk III Escort from Group 2 to 4 was solely about the number of cars they had to produce. I still don't know how they managed it on only 50 more cars though. Perhaps it was allowed because it was a re-homologation of components banned from the end of 1977, which some cars already in Gp 4 got on 50, including (I'm damned sure) the 16-valve head on the TR7, and rationalized the change from Group 2 to Group 4 that the leave on those components had forced on them:

• NB: Mechanical elements recognised in Group 2 before 31.12.75 as well as the
  authorised modifications according to the prescriptions of Art 260 of former
  Appendix J can be used until 31.12.77 for rallies. The car will be automatically
  transferred to Group 4.

BTW, all these documents are on line at FIA.com:
https://www.fia.com/sites/default/files ... full-e.pdf
https://www.fia.com/sites/default/files ... full-e.pdf
https://www.fia.com/sites/default/files ... full-e.pdf
https://www.fia.com/sites/default/files ... full-e.pdf

[dololo]

Hello , i did not explain correctly
i plan to make a TR7 group 4 as close as possible to the car which won the "Boucles de Spa" rally in the 70's
this car had a sprint head and a tubular manifold .
The french federation knows that the exhaust was free , but they want me to prove it was used before allowing me to race .
the purpose is not to respect the rules for them , it is to be as exactly as possible in an historical definition
So i though that proving a dolomite group 2 used a tubular one would be helpful ( i Don't find any document concerning directly the rare tr7 sprint, quickly replaced by V8 cars)

i try to do my best to explain it in English , sorry for my froggy English


have a nice weekend

Laurent

[soe8m]

I will have a check. I do have a lot of period pics of the works dolomites and tr7's.

Jeroen

[dololo]

Good evening ,just a few words to explain i've just bought a dolomite sprint , considering a tr7 would be too difficult to deal with french federation .

Now i have to chose between grp 1 and grp 2 ...

Jeroen, your photos will be wellcome