Borgward RS

Borgward
	Borgward RS, 6th generation
Borgward RS
Production period:	1951-1958
Class :	Sports car
Body versions :	Roadster
Engines:	Petrol engines : ; 1.5 liters ; (49-99 kW)
Length:
Width:
Height:
Wheelbase :	2600-2200 mm
Empty weight :	about 980-595 kg

The Borgward RS was a racing sports car in the class up to 1.5 liters, which Carl FW Borgward G. mb H. Automobil- und Motoren-Werke presented at the International Motor Show in Frankfurt am Main in 1951. By 1958, nine cars of this model had been built and continuously developed. The Borgward RS was a successful car, but often inferior to the Porsche 550, which was better in driving characteristics, despite good engine performance .

history

Records in Montlhéry

Twelve international records in the F class up to 1.5 liters with a car based on the Hansa 1500 on the Linas-Montlhéry route encouraged Borgward to take part in the Formula 2 races if necessary . The record car, with its streamlined aluminum body and 66 hp engine, had a maximum average speed of 172 km / h over 1000 miles. The initiators were the former racing driver and factory sports director of Auto Union , engineer August Momberger , and the engineer Martin Fleischer.

Victories on the Grenzlandring and on the AVUS

Borgward did not start in Formula 2, however, but with a two-seater racing car. Karl Ludwig Brandt had increased the output of the 1.5 liter engine to 80 hp. However, when it was first used in the ADAC Eifel race on May 25, 1952 at the Nürburgring , Hans Hugo Hartmann damaged the rear of the car and retired. In the course of the year, the engine output rose to 90 hp and the first successes were achieved, including victories for Hartmann at the Grenzlandringrennen and at the AVUS . The 53-year-old Adolf Brudes drove a second car, who set a course record in the class up to 1500 cm³ on the Grenzlandring with a speed of 208.3 km / h before it failed with engine failure.

Success at the Nürburgring, bad luck at the Carrera Panamericana

At the Eifel race in May 1953, Brudes and Hartmann took second and third place with the previous year's car in the sports car up to 1500 cm³. After six laps or 136.86 kilometers on the Nordschleife of the Nürburgring, Brudes was 3.6 seconds short of victory. A revised model with a 102 hp engine and a shortened wheelbase was ready in July. Hans Klenk won the AVUS race on July 12th ahead of Hans Herrmann in a Porsche . One of the best results of a Borgward RS was third place in the overall classification of the first 1000 km race on the Nürburgring in 1953 , driven by Karl-Günther Bechem and Theo Helfrich , behind Alberto Ascari / Giuseppe Farina in a Ferrari 375 MM Vigniale and Ian Stewart / Roy Salvadori in a Jaguar C-Type . 51 vehicles started this race, 28 made it to the finish. Borgward sent two cars to the 3,000 km long Carrera Panamericana Rally in Mexico in 1953 . Brudes had a serious accident at the beginning of the event and Hartmann was disqualified shortly before the end because he exceeded the three hours specified for the last stage by 7 seconds after a defect. Until then, Hartmann had led his class one and a half hours ahead of second.

New engine, but criticism of the chassis

Borgward RS, built in 1956, cockpit

In 1954, Borgward entered with three cars, two new builds and one conversion from the previous year. The cars were lighter than their predecessors, but initially still had their two-gasoline engine. At the Eifel race on May 23, Bechem and Hartmann finished the race of sports cars up to 1500 cm³ with a double victory; Brother finished eighth. In the supporting program of the German Grand Prix , the Borgward RS drove with an injection engine for the first time. Bechem finished fifth behind four Porsche 550 Spyder; Hartmann had a serious accident and then gave up his career as a racing driver. Despite increasing criticism of the drivers about the driving behavior of the Borgward sports cars, two started at the Carrera Panamericana in 1954 ; both dropped out by accident.

After the Porsche 550 had proven to be superior, Karl Ludwig Brandt designed a racing engine without using modified series parts. The engine had two overhead camshafts, four valves per cylinder and gasoline direct injection. In the first run on the test bench in early May 1956, it developed 134 hp at 7000 rpm. On July 22, 1956, Helmut Schulze and Erwin Bauer started the Solitude race with the new engine and revised chassis . Schulze finished sixth despite the deteriorating engine power and Bauer retired after losing the track. The cause of the accident was possibly the driving behavior of the Borgward RS, which had already been criticized during test drives. Helmut Schulze later said, among other things: “At the limit, the Borgward reacted significantly more sensitively than competitor vehicles that I know and that I also drove in the race. The transition from 'still sufficient grip' to the instability of the tires was extremely short, emotionally uncomfortable for the driver and difficult to correct. "

Racing break in 1956

After the unsatisfactory result at the Solitude, Wilhelm Büchner, the head of the testing department, withdrew the report on the sports car race as part of the supporting program for the German Grand Prix on August 5, 1956 at the Nürburgring. For the 1957 season, the car was given a torsion-resistant tubular space frame to improve driving characteristics . In addition, a limited slip differential should prevent the rear wheel on the inside of the bend from spinning.

Mountain championship with well-known drivers

Borgward RS with rear attachment; Driver: Fritz Jüttner

With the new vehicles, Borgward took part in the European Hill Climbing Championship , which was held again from 1957 . The drivers were Hans Herrmann, Giulio Cabianca , Joakim Bonnier , Eberhard Mahle and Maurice Trintignant . Herrmann became Vice-Bergmeister.

A disadvantage of the Borgward RS from the beginning was the higher weight compared to the cars of the competition. In 1958, one of them was given a body made of electron , an alloy of magnesium and aluminum, instead of aluminum. This saved 25 kg. To improve the aerodynamics, there was a rear attachment (“backpack”) developed by the aircraft designer Henrich Focke , which could be attached or removed as required, but was firmly integrated into the body of the Elektron car.

The 1958 season was relatively successful with two wins and second place for Joakim Bonnier and third place for Hans Herrmann in the Euro Hill Climb Championship, but Borgward was defeated by Porsche in six hill climbs. As before, the drivers complained about the handling characteristics of the Borgward RS.

Borgward engine in Formula 2

At the end of 1958, Borgward withdrew from racing due to the only moderate success and high costs. The now powerful and stable engine was to be further developed with a view to future series engines and used in other Formula 2 cars. Stirling Moss tested the Borgward RS as early as October 1958 and was enthusiastic. This led to a supply agreement between Borgward and British Racing Partnership in early 1959 , which fitted its Cooper T51 racing cars with Borgward engines. The chief racing fitter and Borgward test driver Fritz Jüttner took over the maintenance of the units. However, the engagement ended at the end of the same year. The engine now made 153–155 hp at 7300 rpm. Moss had won four Formula 2 races with the Borgward engine, Chris Bristow two.

technology

The Borgward RS was the further development of the INKA car, a Borgward Hansa 1500 modified to a record-breaking vehicle. The engine was initially a variant of the inline four-cylinder car engine with an underneath or side camshaft, a stroke of 92 mm and a bore of 72 mm , a so-called long - stroke , but with two carburetors.

The chassis of the first RS consisted of a box frame with cross struts, independent suspension on double wishbones at the front and a De-Dion axle at the rear.

Engines

The engine of the RS with a flange-mounted gearbox was installed behind the front axle, the water cooler in front of the front axle. With a displacement of 1498 cm³, it made 113 to 115 HP at 6000 rpm with direct injection and a compression ratio of 1: 9.8 after the original 80 or 90 HP from 1954 with direct injection .

The racing engine used from 1956 with a housing made of cast silumin (aluminum alloy) was fundamentally different from the versions derived from the series engine. Significant innovations were the changed bore-to-stroke ratio, valve control with two overhead camshafts, double ignition and dry sump lubrication . The stroke was 74 millimeters, the bore 80 millimeters; Cubic capacity 1488 cm³. The cylinders with “wet” cylinder liners had roof-shaped combustion chambers with two spark plugs each, with the injection nozzles in between and two of the four valves in the sloping roof. The valves were controlled directly via the camshafts driven by two duplex chains , on which the timing could be continuously adjusted. The engine developed 134 hp at 7300 rpm, compression ratio 1: 10.5.

In connection with this DOHC engine , the Borgward RS had a five-speed gearbox with a center shift lever, synchronized in gears two to five. From there, the power was transferred to the differential (from 1957 a limited-slip differential) on the rear axle via a cardan shaft .

landing gear

The box frame of the first generations of the RS and the De-Dion axle made the car relatively heavy compared to other racing cars of its time. At around 900 kg, the 1953 version was lighter than the first version, but weighed around 350 kg more than a Porsche 550. In order to reduce the weight, the frame tubes of one of the first cars were drilled through (allegedly 2,000 holes), which However, it only brought a saving of 3.5 kilograms, but on the other hand worsened the torsional and flexural rigidity of the frame, which is considered unsatisfactory anyway. From 1957 a tubular space frame was added to the chassis.

The double wishbones were probably standard parts from the Borgward Hansa 1500, but with angled coil springs and integrated telescopic shock absorbers instead of the standard transverse leaf spring. From the fourth generation, built in 1955/56, the RS had the modified front axle of the Borgward Isabella with hydraulic steering damper. Unlike in the series, the steering levers and tie rods were installed behind the axle beam, but the stabilizer was taken over unchanged. The Gemmer steering was replaced by a horse steering .

With the new fourth generation front axle, the wheelbase was shortened from 2250 to 2200 millimeters, which the drivers hoped would result in higher speeds in the corners.

The De Dion rear axle with a constant 2 degree negative wheel camber remained basically unchanged during the entire construction period. The support tube behind the differential, suspended from coil springs, was guided on a lateral pendulum strut and a V-shaped strut hinged to the center of the frame. The telescopic shock absorbers were attached separately next to the springs.

The hydraulically operated brake system was probably taken over from the Hansa 1500/1800 like other standard parts. Information about the size of the brake drums and the wheels does not exist, so that the standard dimensions can be assumed. From the second generation in 1953, the system had two brake circuits, one of which worked on the front and one on the rear axle. The handbrake acted on the rear wheels with cables and was initially pulled with a lever to the right of the gearbox reaching into the footwell. Later it was a stick handbrake to the left of the driver under the dashboard.

body

The body of the first Borgward RS resembled the INKA record-breaking car with a large Borgward rhombus on the front. According to the already outdated notions of the “streamlined car”, they had a long rear end instead of the aerodynamically more favorable spoiler lip. A huge air scoop in the middle of the bonnet was supposed to supply more air to the carburettors through dynamic pressure and increased air resistance. As early as 1953, the short-tail version appeared with just a flat curve instead of the scoop. From the third generation in 1954, there was also no arching. The body received three air holes on both sides and four exhaust pipes protruded into the open on the right between the front wheel opening and door. In the following two years there were only two pipes. For the 1957 season, instead of a small individual window, the car was given a windshield that spanned the entire width of the cockpit.

The opening for the exhaust in the right side section was retained in two of the last generation cars, although only one pipe was led outside just before the rear wheel. The third car of the 1958 season had a body made of electrons instead of aluminum on a tubular space frame and thus weighed 595 kilograms. The sides were smooth and the front sloping forward. Furthermore, all-round glazing of the cockpit, aerodynamically clad headlights, a narrow cooling air opening and a crest as an integral part of the car's aerodynamic properties improved .

literature

Heinrich Völker: Silver Arrows from Bremen - Racing Sports Cars from the Borgward Works ( Cars from Bremen, Volume 7). Verlag Peter Kurz, Bremen 2004, ISBN 3-927485-43-8 .

Web links

Commons : Borgward RS - collection of images, videos and audio files

Remarks

↑ The chassis number 60012 of the last Borgward RS suggests that there were twelve of these vehicles. However, three converted cars may have been renumbered. Many Borgward documents were lost after the bankruptcy, making research difficult.
↑ INKA was the abbreviation for "Ingenieurs-Konstruktions-Arbeitsgemeinschaft", August Momberger's design office.

Individual evidence

↑ ^a ^b ^c Peter short: Carl FW Borgward automobile works - economic miracle in large format . Verlag Peter Kurz, Bremen 2001, ISBN 3-9806977-3-8 .
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Heinrich Völker: Silver Arrows from Bremen - racing cars from the Borgward works. Verlag Peter Kurz, Bremen 2004, ISBN 3-927485-43-8 .
↑ Michael Behrndt, Jörg-Thomas Födisch, Matthias Behrndt: ADAC Eifelrennen . Heel Verlag, Königswinter 2009, ISBN 978-3-86852-070-5 .
↑ ^a ^b auto motor und sport . Borgward RS 1500 . Retrieved October 20, 2018.

[1] The chassis number 60012 of the last Borgward RS suggests that there were twelve of these vehicles. However, three converted cars may have been renumbered. Many Borgward documents were lost after the bankruptcy, making research difficult.

[6] INKA was the abbreviation for "Ingenieurs-Konstruktions-Arbeitsgemeinschaft", August Momberger's design office.

[Autos_aus_Bremen-2] Peter short: Carl FW Borgward automobile works - economic miracle in large format . Verlag Peter Kurz, Bremen 2001, ISBN 3-9806977-3-8 .

[Völker-3] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Heinrich Völker: Silver Arrows from Bremen - racing cars from the Borgward works. Verlag Peter Kurz, Bremen 2004, ISBN 3-927485-43-8 .

[Eifelrennen-4] Michael Behrndt, Jörg-Thomas Födisch, Matthias Behrndt: ADAC Eifelrennen . Heel Verlag, Königswinter 2009, ISBN 978-3-86852-070-5 .

[ams-5] uto motor und sport . Borgward RS 1500 . Retrieved October 20, 2018.