Waarschijnlijk omdat dit de eerste 4 (prototypes) waren?
In 1967, Porsche engineers, under Dr. Ferdinand Piech, created what has to be one of the most unique variations of the 911 - the competition 911R of which only 24 examples, including four prototypes, where made.
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(...)Piech decided to see how many pounds he could sweat off the 911 in the latter part of 1966, even though the effort would have little short term effect on the factory's racing fortunes.
Because there was no initial intention to homologate the 911R, its meager record of achievement doesn't seem so bad as it might have been. (sales department rejected the idea of homologation of 500 units for the FIA).
Results aside, the true importance of the 911R is that it formed the basis for all of Porsche's future lightweight models, including the Carrera RS and RSR's as well as the later 934 and 935 Turbos.
The first four prototypes (chassis: 305876S-R/1, 306681S-R/2, 307671S-R/3 and 307670S-R/4) came to the experimental department as complete production 911S models in the latter months of 1966 and early 1967.
Stripped down to their bare shells, the cars were transformed into 911Rs by the engineers and emerged in their new configuration between March and April in 1967.
This process not only involved weight saving, but also a engine-transplant from one of Piechs other creations, the 906.
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While it also had been intended to replace the bumpers, doors and front fenders, as well as the hood and rear decklid, with feather-weight substituses, there was little agreement on the best material to use in the manufacturing of these pieces.
Ik denk dus dat omdat het in eerste instantie om maar 4 protos ging, men de mallen van de 'gewone' 911S onderdelen heeft gebruikt.
Ultimately, they were produced both in Aluminium and fiberglass (GFK) with all four prototypes wearing a mixture of these panels until fiberglass was decided on as the choice for the 20 car production run. Costs were taken into account at this point and the extensive use of aluminium would have raised the price of the production 911R several thousands of DMs.
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Eventually they would build special taillight and parkinglight housings which were shells of what the street-customer had come to expect and which today are considered visual keys to the 911R's identity.
Dit is 'm, de #3:

En je ziet: hier had ie ook de gewone schermen.
Ook leuk:
