Question: Which founder of the Porsche company had Karl Rabe's help in developing his cars' transmissions?

Context paragraphs:
Ultima GTR: The Ultima GTR is a super car manufactured by Ultima Sports Ltd of Hinckley, Leicestershire, England, and described by commentators as a "supercar".  The car was available both in kit form and as a "turnkey" (i.e. assembled by the factory) vehicle until early 2015, when it was replaced by the Ultima Evolution.  The design is mid engined, rear wheel drive layout, with a tubular steel space frame chassis and GRP bodywork.  A convertible version called the Ultima Can-Am was also produced.  Kit builders were free to source and fit a variety of engines and transmissions but the Chevrolet small block V8 supplied by American Speed mated to either a Porsche or Getrag transaxle was the factory recommended standard, and this configuration was fitted to all turnkey cars.

Porsche 356: The Porsche 356 is an iconic sports car which was first produced by Austrian company Porsche Konstruktionen GesmbH (1948–1949), and then by German company Dr. Ing.  h. c. F. Porsche GmbH (1950–1965).  It was Porsche's first production automobile.  Earlier cars designed by the Austrian company include Cisitalia Grand Prix race car, the Volkswagen Beetle, and Auto Union Grand Prix cars.

Hegersport: Hegersport GmbH is a German auto racing company which serves as organizer for German Porsche Sports Cup series, as well as a racing team which competed in the FIA GT1 World Championship under the title Triple H Team Hegersport.  The company was formed in 2000 by racing drivers Altfrid Heger and Christof Maischak in Essen, Germany, originally organizing the V8Star Series for touring cars in Germany and across Europe.  Following the end of the V8Stars series in 2004, Hegersport coordinated with Porsche Germany to establish the Sports Cup series, a national series for Porsche drivers.  Hegersport also serves as a private customer event organizer, and provides training and safety courses for individuals.

Porsche 64: The Porsche 64, also known as the Type 64 and Type 60K10, is considered by many to be the first automobile from what was to become the Porsche company, and a true design precursor to the post-war production model.  The model number comes from the fact that it was built mainly from design drawings for the Type-64 "record car".  Most mechanical parts came from the 38 prototype series.  The chassis was heavily reinforced and the engine also reworked to produce around 40 horse power.  The Type-64 was only a drawing until the three racers were built.  The body was also a compromise in that the cab had to look like a KdF car , but the rest was 'record' car.  The VW beetle was the Type-60, and the name the "60K10" means body design 10 for the Type-60 Beetle.  Its flat-four engine produced 50 bhp and gave a top speed of around 160 km/h .

Cruise-O-Matic: Ford-O-Matic was the first automatic transmission widely used by Ford Motor Company.  It was designed by the Warner Gear division of Borg Warner Corporation and introduced in 1951 model year cars.  In contrast to Detroit Gear Division's three band automatic originally designed for Studebaker which became superseded by this unit, a variation of Warner Gear's three-speed unit named Ford-O-Matic continued to evolve later into Cruise-O-Matic named transmissions in 1958 and finally the FMX named transmissions in 1968.  This line continued in production until 1980, when the AOD was introduced.  Like Ford, variations of this same Borg Warner design were used by other automobile manufacturers as well, such as AMC, International Harvester, Studebaker, Volvo and Jaguar, each of them having the necessary unique adaptations required for the individual applications.

Direct-shift gearbox: A direct-shift gearbox (German: "Direkt-Schalt-Getriebe" ), commonly abbreviated to DSG, is an electronically controlled dual-clutch multiple-shaft manual gearbox in a transaxle design, without a conventional clutch pedal and with fully automatic or semi-manual control.  The first actual dual-clutch transmissions were derived from Porsche in-house development for 962 racing cars in the 1980s.

Karl Rabe: Karl Rabe (29 October 1895, Pottendorf, Austria - 28 October 1968) was an automobile designer and was the Chief Designer at Porsche.  He helped Ferdinand Porsche to develop the Porsche's transmissions.

Ferdinand Porsche: Ferdinand Porsche (3 September 1875 – 30 January 1951) was an automotive engineer and founder of the Porsche car company.  He is best known for creating the first gasoline-electric hybrid vehicle (Lohner-Porsche), the Volkswagen Beetle, the Mercedes-Benz SS/SSK, several other important developments and Porsche automobiles.  In addition, Porsche designed the 1923 Benz Tropfenwagen, which was the first racing car with a mid-engine, rear-wheel drive layout.

9ff GT9: The 9ff GT9 is a sports car based loosely on the Porsche 911, built by German tuning company 9ff, founded by Jan Fatthauer.  Based on the Porsche 911 (997) GT3; the cars are extensively rebuilt and fitted with a heavily modified 4.0 litre flat 6 that produces 738 to , depending on the configuration.  One of the major differences from a normal 911 is the positioning of the engine; whilst every 911 throughout Porsche's history (excluding the Porsche 911 GT1 racer) has been rear-engined, the GT9 is mid-engined for better weight distribution.

Eugene Rabe: Eugene Karl Rabe (May 8, 1911 – 1974) was a German-American astronomer.

Supporting paragraphs: Karl Rabe Ferdinand Porsche
Answer: Ferdinand Porsche