The fiche
The document that described the car was also the document that constrained it — and the gap between those two functions is where most of the engineering happened.
01What the form was
Every car that competed in a regulated FIA class did so because a homologation form — the fiche d'homologation — said it was legal. The fiche was a standardised document submitted to the FIA by the manufacturer, accompanied by photographs, technical drawings and, where required, proof that the minimum production run had been completed. Once accepted, it was the definitive record of what the car was: dimensions, weight, engine specification, transmission, suspension geometry, tyre sizes. Scrutineers checked cars against it. If something on the car was not on the fiche, that thing was illegal, regardless of whether it offered any performance advantage.
That logic ran in both directions. The fiche did not merely describe the car — it bounded it. A manufacturer who wanted to run a different brake caliper, a different inlet manifold or a different suspension pickup point had to go back to the FIA, file an amendment, and wait. The document was the car, in regulatory terms, and building the car began with building the form.
02The form as engineering tool
In the Group B era, the fiche became a design instrument in its own right. Appendix J of the FIA's sporting code established the framework — the tables, the categories, the permitted variations — and manufacturers read it as carefully as any dimensional specification. The entry on each line of the fiche represented a choice: specify narrowly and gain precision, specify broadly and gain flexibility. A dimension written as a range rather than a fixed value left the team room to adjust. An option listed as a variant kept a development path open.
The document was the car, in regulatory terms, and building the car began with building the form.
The evolution allowance made this more acute. The rules permitted a small additional production run — twenty cars in the Group B structure — that could carry modifications too significant for a simple amendment. Teams treated the evolution homologation as a scheduled engineering reset, a moment to absorb development that had outgrown the original fiche. Lancia's engineers at Abarth in Turin built the Delta S4 knowing the evolution car would be a different vehicle in almost every meaningful dimension; the fiche sequence was planned before the first car was finished.
Chronology
- Appendix J frameworkgoverned Group B from the class's introduction in 1982 through its abolition after the 1986 season
- Evolution carstwenty units permitted above the 200-car production minimum, used by Lancia, Peugeot and others as a deliberate development tool
The Peugeot 205 T16, developed by Peugeot Talbot Sport under Jean Todt, followed the same discipline. The production-specification fiche and the evolution fiche were coordinated documents, each written to make the next step legitimate rather than improvised. What a scrutineer could measure, a designer had to anticipate — and the fiche told the designer exactly what the scrutineer would be measuring.
03What scrutineers actually did with it
At an event, scrutineering was a comparison exercise. The car arrived; the fiche arrived; the two were reconciled. Physical gauges and templates confirmed that the body was the body on the form, that the engine number corresponded to a homologated specification, that nothing had been substituted between parc fermé and the start. The burden of proof ran entirely in one direction: the car had to match the document, not the other way around.
A part absent from the fiche was not a minor irregularity — it was grounds for exclusion. That severity was intentional. If the penalty for running an unlisted part had been a points deduction, teams would have calculated the odds. Exclusion made the arithmetic simple, which meant the fiche remained what the FIA intended it to be: not a guideline but a definition.
The practical effect was that manufacturers spent significant engineering time on paperwork — not as an administrative task but as a technical one. Writing the fiche well was part of building a competitive car. The teams who understood that earliest tended to arrive at each event with the most latitude. The fiche was a constraint, but a constraint with a geometry, and geometry can be worked.