Test Sheet - FIA/CSI Homologation Nr. 3025

[McOtto]

Using archival data, I am trying to substantiate Porsche’s rationale for making the Recaro Sportsitz standard on the 1971 911S. Multiple knowledgeable people have indicated it was because of FIA homologation.

I was able to find “Test Sheet - FIA/CSI Homologation Nr. 3025” (attached for convenient reference) and its addendums. It was initially submitted on November 1969 for “year of construction” 1969 and “model year” 1970. The final addendum appears to be dated November 1973.

Based on those sources, I drafted the following preliminary explanation:

In order for a car to participate in motorsport competitions sanctioned by the Fédération Internationale de l'Automobile (FIA), the car must be approved by the FIA in a process called homologation. Archival “Test Sheet - FIA/CSI Homologation Nr. 3025” and its addendums include the 1971 911S and incorporates the Recaro Sportsitz by specific reference/photograph on page 14 of the Test Sheet. Therefore, Porsche made the Sportsitz standard equipment on the model year 1971 911S to ensure FIA homologation compliance and to achieve the Category A, Group 2 Grand Touring requirement of a minimum of 500 identical production cars in a consecutive 12 month period.

However, correct me if I am wrong and apologies for my confusion, but it appears Homologation Nr. 3025 covers multiple addendums and multiple 911S model years.

If that is the case, can anyone explain why the Sportsitz were uniquely standard on the model year 1971 911S?

[davep]

I believe that the greatest difficulty for the 1971 911S was the rear seats. Perhaps in an effort to provide maximum rear seat space the front seats had to be minimized, and the Recaro Sportsitze aided in that requirement.

[edmayo]

I agree with Dave, from what I've seen on the subject, goes with the rear seat inserts to meet rear seat leg room to qualify for sedan classing.

[McOtto]

Thank you, gentlemen. That makes sense. While I do not remember a specific reference to the Sportsitz in Michael Scott’s “The Lost Archive” book, I do recall considerable dimensional drawings related to front seat/back seat orientation.

https://www.early911sregistry.org/fo...k-2nd-printing

I am guessing the rear seat dimensional issue was not unique to model year 1971. But it seems reasonable to assume Porsche may have encountered difficulties producing 1,000 “identical” (as defined by FIA) homologation cars prior to model year 1971 because they relied on customers to choose the Sportsitz option. Making it standard for model year 1971 may have represented a means to enhance homologation production numbers???

Correcting my previous explanation to include this new info:

In order for a car to participate in motorsport competitions sanctioned by the Fédération Internationale de l'Automobile (FIA), the car must be approved by the FIA in a process called homologation. FIA Appendix “J” to the International Sporting Code, Article 253.B – Coachwork extensively specifies the number of seats and minimum inside dimensions.

Porsche had previously specified the Sportstiz in the model year 1969/70 911S FIA Nr. 3025 Group 3 homologation. However, indications are when Porsche applied for FIA homologation on the model year 1971 911S, they attempted to secure approval for FIA Group 2 (4-seater special touring car). The FIA application incorporated the Sportsitz and a removable rear seat extension. Porsche reportedly contended the combination met the Article 253.B requirements. However, actual passenger use of the rear seats with the extensions installed significantly reduced leg room, thus physically restrictive, and reportedly did not achieve FIA approval.

The exact reason Porsche made the Sportsitz standard equipment on the model year 1971 911S, when not doing so on previous model years, is elusive. FIA Category A, Group 2 special touring car compliance requires a minimum production of 1,000 “identical” (as defined by FIA) cars in 12 consecutive months. Deductive reasoning points to the possibility that slumping sales of the 911S prompted Porsche to make the Sportsitz standard in an effort to increase the number of 911S production cars equipped to Article 253.B requirements.

As it ultimately turned out, Porsche and the FIA were unable to reach agreement on Article 253.B compliance, Porsche withdrew its homologation application, and for model year 1971 Porsche did not produce anything close to 1,000 911S homologation cars.

For those that may be interested, this link will take you to the FIA Historic Database: https://historicdb.fia.com/regulatio...iod-appendix-j

Please let me know if I am missing the mark. Thank you!

[McOtto]

Bumping this to the top with the hope fellow ESR members might find errors or validate my explanation above.

Additionally, does anyone know how many 1971 911S homologation cars were actually produced before Porsche withdrew the Nr. 3025 Test Sheet application?

Thank you!