The 1968 Porsche 911R is one of the most sought after variants of the early 911 series. Based on the contemporaneous 911S, it was produced by Porsche to compete in FIA’s GT 2.0 category. To make it competitive, the 911R was powered by a flat-six engine, Type 901/22 from the Porsche 906, capable of 210 hp (compared to the 160 hp of the standard 911S). Weight savings came in the form of removed creature comforts, along with fiberglass panels throughout. Curb weight came in at less than 1,800 pounds dry. According to RM Sotheby's, "four prototypes were constructed, 305876 (R1), 306681 (R2), 307671 (R3) and 307670 (R4), after which Porsche had coachbuilder Karl Baur build another 20 examples in a numbered production series, 118990001R-118990020R." Interestingly, given the extent of modifications to the 911R, the FIA refused to homologate the car for the intended series. Instead, most samples were sold to privateers and raced successfully throughout the world.