Development of the model RR Toyopet Master

Alongside the development of the Model RS passenger car, development of the Model RR passenger car started in October 1953 as a successor to the Model RHK passenger car manufactured by Kanto Auto Works, Ltd.

Where the Model RS passenger car employed front-wheel independent suspension, the Model RR passenger car used a beam front suspension that followed that of the Model RHK. This sturdy structure was targeted at the taxi industry, which has harsh requirements for vehicles that can withstand great wear-and-tear. The chassis was constructed from parts passed down from the RHK passenger car and parts common with the Model RS passenger car.

In charge of the development of the Model RR passenger car was Project General Manager Tozo Yabuta, but Kanto Auto Works, Ltd. stayed in charge of body design. Because of the policy to sell completed cars for the RS passenger car, the mounting business for the RHK passenger cars at Kanto Auto Works, Ltd. disappeared, and Project General Manager Tozo Yabuta was therefore hastily tasked with developing the RR passenger car as its successor.

The chassis of the RR passenger car was manufactured at Toyota Motor Co., Ltd.'s Koromo Plant, and was then sent to Kanto Auto Works, Ltd. in Yokosuka City, Kanagawa Prefecture for the body mounting. The first Model RR prototype was completed in March 1954, and mass production started in September of the same year.

The Model RR passenger car was given the name of Toyopet Master, and was launched on August 1, 1955 at the same time as the Toyopet Crown. Table 1-41 gives an overview of the detailed specifications of both cars as well as the Model RH Super.

Table 1-41. Specifications of the RS Crown, RR Master, and RH Super (1955)

Item
Model RS Crown
Model RR Master
Model RH Super
Length
4,285 mm
4,275 mm
4,280 mm
Width
1,680 mm
1,670 mm
1,590 mm
Height
1,525 mm
1,550 mm
1,600 mm
Wheelbase
2,530 mm
Same as left
2,500 mm
Track (front)
1,326 mm
1,317 mm
1,325 mm
Track (rear)
1,370 mm
Same as left
1,350 mm
Minimum ground clearance
210 mm
200 mm
190 mm
Standard floor height
320 mm
370 mm
410 mm
Vehicle weight
1,210 kg
Same as left
1,150 kg
Seating
6
Same as left
5
Maximum speed
100 km/h
Same as left
Same as left
Engine model
Toyota R engine
Same as left
Same as left
Cylinders
Inline, 4-cylinder
Same as left
Same as left
Total engine displacement volume
1,453 cc
Same as left
Same as left
Maximum output
48 hp/4,000 rpm
Same as left
Same as left
Maximum torque
10m-kg/2,400 rpm
Same as left
Same as left
Battery voltage
12V
Same as left
6V
Clutch operating format
Hydraulic transmission
Same as left
Link type
Transmission
3 forward gears, synchromesh type
Same as left
4 forward gears
Constant-mesh helical gear
Same as left
Sliding mesh gear
Remote control
Same as left
Direct control
Control gear
Worm and selector roller
Same as left
Same as left
Front suspension
Wishbone independent
Reverse Elliot I-beam
Same as left
Rear suspension
Semi-floating banjo
Same as left
Same as left
Brakes
Hydraulic floating shoe with rear wheel manual
Same as left
Hydraulic internal expansion
Front springs
10 coils
5-leaf
8-leaf
Rear springs
3-leaf
5-leaf
9-leaf
Frame
Ladder closed cross section
Ladder open cross section
Same as left
Source:
Toyota Engineering Society's, Toyota Technology, July 15, 1955

Furthermore, the chassis of the Model RR Toyopet Master was remodelled at Kanto Auto Works, Ltd., and the Masterline series, mounted with an interchangeable body, was developed. The models in this series were the Model RR16 Masterline single cab pickup and the Model RR17 Masterline station wagon, launched in September of the same year, and the Model RR19 Masterline double cab pickup, launched in August 1956.

Subsequently sales of the Model RR Toyopet Master were stopped in December 1956, and manufacturing at Kanto Auto Works, Ltd. centred on the Masterline series. For this series approximately 19,400 vehicles were manufactured by March 1959 for the three models combined.

Kanto Auto Works, Ltd. developed the first-generation Model ST10 Toyopet Corona in July 1957, using the body of the Model RR Toyopet Master.

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