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World Land Speed Record on a Public Highway

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    World Land Speed Record on a Public Highway

    An article that recently appeared in Issue 510, December 9th 2008 of the Australian online automobile magazine, AutoSpeed, reminded me of this event and, since the record still stands, those of you unfamiliar with the details may find the account interesting. The article is titled "The Record Breakers" and is available at:
    http://autospeed.com:80/cms/A_110813/article.html

    In 1934 Germany, the newly-founded AutoUnion, one of the precursors of Audi, established the one-hour world speed record in a first attempt. This was a challenge that Mercedes-Benz was compelled to address. At the end of 1934, the great Rudolf Caracciola, M-B top racing driver at the time, established new records in Gyon, Hungary, and on the AVUS racetrack in Berlin. For a brief biography of this accomplished race driver, go to:
    http://en.wikipedia.org/wiki/Rudolf_Caracciola

    For the next couple of years, the two marques fought each other in the major European GP 750 kg formula races. In May 1937, the AVUS racetrack was the venue for a free-formula race (cars that weighed more than 750 kg with no upper limit). Hermann Lang, in a fully streamlined M-B W125, won the race at an average speed of 261.7 km/h (162.6 mph). The car was powered by a V12 engine rather than the V8 used in the 750 kg racing formula. The outcome prompted M-B to attempt a world record run later in the year using this engine.

    AVUS (Automobil Verkehrs und Ubungs-StraBe) was a racetrack on the southwestern outskirts of Berlin. Designed in 1907 by the Automobilclub von Deutschland, after many delays the circuit opened in 1921. At the time of opening, AVUS was 19.5 km (12 miles) long - each straight being approximately half that length, and joined at each end by flat, large-radius curves. From 1927, AVUS faced competition from the Nurburgring so in an effort to make AVUS the world's fastest track, the north curve was turned into a steep banking (43 deg) made of bricks. This was its configuration during the Lang and Caracciola record attempts in the 1930s. Subsequently, the track has been reconfigured and shrunk, and today no longer exists as it is part of the public highway system, Autobahn A115 (I think).

    Since Europe lacks anything remotely similar to the Bonneville Salt Flats, with the permission of the German government the decision was made to use a section of the Autobahn which was under construction in Germany at the time. A 34 km (21.1 mile) length of a brand-new, absolutely level stretch of roadway that ran between Frankfurt and Darmstadt was chosen. I think it's designated A5 today.

    The DAB V12 engine was developed for GP racing. With a displacement of 5577 cc (340.3 CID), it wasn't much larger than the V8 but had more power than any other M-B engine at the time. In its final form it developed 736 HP at 5800 rpm and 1000 Nm (738 lbs/ft) torque. The cylinder bank angle was 60 deg to ensure equal firing intervals and unlike most V-engines, the cylinders of each bank were exactly opposite each other rather than offset. This was accomplished by using a blade and fork big end construction for the con rods. Such a design produces minimal crankshaft length for lowest tosional vibration. Like the inline-6 engine, the V12 has both its primary and secondary unbalanced forces completely eliminated.

    The aluminum crankcase had forged steel cylinders with 4-valves per cylinder operated by DOHCs in each welded on cylinder head. Two Roots-type superchargers arranged in a V-shape at the front of the engine were driven by a hollow-shaft extension of the crankshaft. The boost pressure was 1.28 atmospheres (1.3 bar; 18.8 PSI). To provide adequate VE at high rpm, the engine was equipped with two carburetors per bank. The engine was front-mounted along the longitudinal axis of the car and the rear wheels were driven. A 4-speed M/T was fitted.

    Front suspension consisted of double wishbones with coil springs and hydraulic shocks while the rear was fitted with a De Dion axle with torsion bar springs and hydraulic shocks. Steering was by worm and nut. Braking was carried out by light-alloy drums fitted with cast iron liners.

    The streamlined body was under continuous development from its inception in 1935 until the record run at the beginning of 1938. Aerodynamic lift was a continuing problem that revealed itself as racing speeds increased. In the fall of 1936, Caracciola established three class records over five and ten kilometers, and ten miles, on the autobahn near Frankfurt. At an average speed of 333.5 km/h (207.2 mph), the ten mile run was also a world record. In the May 1937 AVUS race, the front of Lang's car lifted off after driving across a bump in the road at 370 km/h (230 mph) because of too little downforce. After this was corrected, the car was taken to Frankfurt for another record attempt to be held between October 25th and 31st 1937. On a test run, Caracciola's car lifted off again and was sent back to the factory for nose modifications and the addition of 90 kg (198.4 lb) of lead to the front end. Back on the road, Caracciola reached a speed of 397 km/h (247 mph) on one kilometer from a flying start, but the AutoUnion car was still faster at 406 km/h (252 mph).

    The German sanctioning body at the time, the ONS, arranged a return match in January 1938. After the October disappointment, the DAB V12 engine received modified pistons, piston clearance, wrist pins, carburetors, intake manifold and supercharger drive. The body received its final shape through testing in an aircraft wind tunnel in Berlin instead of using a scale model as in previous aerodynamic modifications. With a Cd (aerodynamic drag coefficient) value of 0.157, unmatched by any other motor vehicle at the time, a dry weight of 1185 kg (2612.5 lb), and riding on 6.25 x 22" front tires and 7.00 x 24" tires at the rear, the car was now ready for its record-setting run.

    On January 28th 1938 shortly after 8 am, Caracciola made a trial run and then, after a few last minute adjustments, immediately made his record attempt. The speeds he attained that day, 432.7 km/h (268.9 mph) over one kilometer from a flying start, and 432.0 km/h (268.4 mph) over one mile from a flying start have to this day remained the highest speeds ever recorded on a public road.

    The car is on display at the M-B museum in Stuttgart.

    Happy Motoring!

    Below is a photo of the streamliner as it appears at the museum.
    Attached Files
    Last edited by goldstar; 04-21-2010, 11:31 PM.
    02 DX Millenium Red - The Penultimate Driving Machine
    MP3 Strut Tower Bar kit; Cusco Front Lower Arm Tie Bar
    MSP Springs, Struts, Stabilizer Bars, Trailing Links, #3 Engine Mount
    Kartboy Stabilizer Bar Bushings; Nyloil Shifter Bushings; Red Line MT-90 Gear Oil
    MP3 Shifter, Knob and Aluminum Pedal Set
    Suvlights HD Wiring Harness; Osram Night Breaker H4 Bulbs; Exide Edge AGM Battery
    Summer: 5Zigen FN01R-C 16 x 7" Wheels; Yoko S.drive 205/45-16s
    Winter: Enkei OR52 16 x 7" Wheels; Falken Ziex ZE-912 205/45-16s
    Modified OEM Air Intake; Racing Beat Exhaust System; Techna-Fit SS Clutch Line
    Denso SKJ16CR-L11 Extended Tip Spark Plugs; Magnecor Wires
    Power Slot Front Brake Rotors; Techna-Fit SS Brake Lines; Hawk HPS Pads
    Red Line Synthetic Engine Oil; C/S Aluminum Oil Cap
    Cyberdyne Digital Gauges: Tach; Ambient Air Temp; Voltmeter

    #2
    Mercedes-Benz T80

    The story of the LSR set on a public highway reminded me of another attempt to again break the record on a similar venue. I did some research and this is the result.

    One of the most successful German auto racers of the pre WWII period, Hans Stuck, was determined to set the world's Land Speed Record (LSR), and convinced M-B to build a special racing car for the attempt. The fact that Stuck was a favorite of Hitler, who himself was a racing fan and officially sanctioned the project, may have had something to do with M-B's agreement to take on the project. As the record attempt was to be made on German soil, Hitler viewed the project as another potential propaganda triumph of German technological superiority. This was to be another LSR attempt carried out on a public highway rather than a race course. Stuck was to drive the car over a special section of the Dessau Autobahn (now part of the A9 Autobahn) which was 25 m (82') wide and 10 km (6.2 miles) long with the median paved over.

    Planning began in 1937 with the selection by M-B of Dr. Ferdinand Porsche as the mechanical designer, and the aircraft designer and aerodynamics specialist Josef Mikci responsible for the body design. The car was to be called the T80. Porsche first envisioned a maximum speed of 550 km/h (340 mph), but after George Euston's and John Cobb's successful LSR run of 1938-39, the target speed was raised to 600 km/h (373 mph). By the completion of the project in late 1939, the target speed was made still higher at 750 km/h (465 mph).

    The powerplant chosen was the Daimler-Benz DB 603 inverted V12, derived from the DB 601 aircraft engine which powered, among other models, the Messerschmitt Bf 109, one of the most lethal fighters in the Luftwaffe. In fact, the DB 601 powered a Messerschmitt Me 109 to a world's speed record of 754.6 km/h (468.9 mph) in 1939. While the 601 had a displacement of 33.9 L (2,069 CID), weighed 700 kg (1,540 lb) dry, and developed 1,360 HP at 2,600 rpm, the 603 displaced 44.5 L (2,715 CID), weighed 910 kg (2,002 lb) dry, and had an output of 2,830 HP at 2,800 rpm. Among other aircraft, it powered the Heinkel He 219 and the Messerschmitt 410.

    With a 60 deg bank angle, blade and fork con rod construction, and roller bearing rather than plain bearing big ends, it employed direct cylinder injection and utilized a gear driven centrifugal supercharger. Interestingly, the left block had a CR of 7.5:1 while the right block had 7.3:1. This has never been satisfactorily explained perhaps because of the massive technical document destruction that took place in Germany during WWII. One theory, not universally accepted is that the unusual side placement of the supercharger with possible resultant inequality of flow between banks may have been responsible. Having raised the target speed to 750 km/h, Dr. Porsche calculated that 3,000 HP would be required to achieve this goal. Consequently, the engine was tweaked to reach this level.

    The engine was designed to run on a mixture of methanol (63%), benzene (16%), ethanol 12%), acetone (4.4%), avgas (2%), and ether (0.4%). Methanol/water injection was used for charge cooling as an anti-detonant.

    The Daimler-Benz company was formed in 1926 when Daimler Motoren Gesellschaft (the parent company of Mercedes) merged with Benz. The company quickly entered the liquid-cooled V12 aircraft market. The prototype DB 600 engine was built in 1934. The engines were built in Stuttgart-Unterturkheim where the M-B car factory was (and still is) located, and also in other locations to fulfill the needs of the Luftwaffe during WWII. Since the DB series engines were direct injected, they had an advantage over carbureted Allied aircraft such as the Spitfire whose carbs were affected by negative Gs during flight maneuvers (thank God for Miss Tilly's orifice). It's been said that the experience M-B gained in the high performance aircraft field helped shape the engineering excellence of the company after WWII in the postwar automobile industry.

    In order to transmit the torque to the road surface, the vehicle was designed to ride on three axles, the two rear being powered. In final form, the T80 was over 8 m (27') long, and weighed 2.7 metric tons. Aerodynamically, the car incorporated two small wings at its midsection to prevent the vehicle from veering off course at speed through a downforce mechanism patented in 1939 by Mikci. The enclosed cockpit, low sloping hood, rounded fenders, and elongated twin-tail booms were Porsche designed. The Cd was a low 1.8.

    The record attempt was set for January 1940 during "RekordWoche" (Record/Speed Week) but the events of September 1939 obviously resulted in its cancellation as well as those of any other motorsport activities scheduled to take place in Europe. During the war, the engine was removed from the car and the vehicle was moved to Karnten, Austria for safekeeping. Surviving the war, the T80 was eventually moved to the M-B Auto Museum in Stuttgart where it can be seen, minus the engine, today.

    In 1947, John Cobb in the Railton Mobil Special at Bonneville raised the LSR to 634 km/h (394.196 mph), 116 km/h (72 mph) slower than the 750 km/h (465 mph) projected for the T80 in 1940. Over the years, many people have urged M-B to restore the T80 to its original specifications to see if it could meet its projected goal. Undoubtedly, such a run if it did occur would not take place on the modern Autobahn system.

    FYI, Cobb's car was powered by engines built by the British company Napier and Sons, Ltd. The Napier Lion aircraft engine was designed and first built in 1917 (this is not a misprint). It was a W12 with 60 degs between each of the three banks, 4-valve per cylinder, DOHC (total 6-camshafts) engine. The two Napier Lion engines used by Cobb had earlier been used in aircraft flown in the 1929 Schneider Air Trophy Race. Each engine developed 1,250 HP at 3,600 rpm. The rear engine drove the front wheels, and the front engine the rear wheels with no driveline connection between the two so Cobb (a WWII pilot) had to keep the throttles balanced in addition to his other duties. The car weighed 3-tons and had no tail fin to keep it straight at speed.

    References:
    http://www.absoluteastronomy.com/top...cedes-Benz_T80
    Allied Aircraft Piston Engines of World War II, by Graham White; Section1, Chapter 6: Napier, pages 155 to 180.


    Happy Motoring!

    Photos of the car as currently displayed at the M-B museum, and some views of the chassis and powerplant, both in and out of the car, are reproduced below:

    Attached Files
    02 DX Millenium Red - The Penultimate Driving Machine
    MP3 Strut Tower Bar kit; Cusco Front Lower Arm Tie Bar
    MSP Springs, Struts, Stabilizer Bars, Trailing Links, #3 Engine Mount
    Kartboy Stabilizer Bar Bushings; Nyloil Shifter Bushings; Red Line MT-90 Gear Oil
    MP3 Shifter, Knob and Aluminum Pedal Set
    Suvlights HD Wiring Harness; Osram Night Breaker H4 Bulbs; Exide Edge AGM Battery
    Summer: 5Zigen FN01R-C 16 x 7" Wheels; Yoko S.drive 205/45-16s
    Winter: Enkei OR52 16 x 7" Wheels; Falken Ziex ZE-912 205/45-16s
    Modified OEM Air Intake; Racing Beat Exhaust System; Techna-Fit SS Clutch Line
    Denso SKJ16CR-L11 Extended Tip Spark Plugs; Magnecor Wires
    Power Slot Front Brake Rotors; Techna-Fit SS Brake Lines; Hawk HPS Pads
    Red Line Synthetic Engine Oil; C/S Aluminum Oil Cap
    Cyberdyne Digital Gauges: Tach; Ambient Air Temp; Voltmeter

    Comment


      #3
      impressive . i thought i had lots of car info in the brain.. good write up goldstar..

      Comment


        #4
        Thanks, tireboy.

        What I find so interesting and amazing when looking back at past automotive achievements is the level of design and engineering sophistication back in the day when automotive and aircraft technology was still so young, and relatively primitive (or at least we tend to think so).

        SOHC and DOHC engines with more than 2-valves/cylinder along with centrifugal superchargers in the 1920s, direct cylinder injection and mechanically-controlled fuel injection systems in the 1930s, and turbochargers in the early 1940s (made by GE in the US) despite the limits of metallurgy at the time. Just to name a few of the highlights.

        Contrast that with the automotive scene in the US after WWII when, until the OHV engine displaced it by the mid-fifties, for many performance enthusiasts the choice was the flathead Ford V8. They sure looked cool with their aftermarket finned aluminum heads, and their twin (and sometimes triple) 2-barrel Holley carb aluminum intake manifolds (and those chrome air cleaner covers) but no amount of porting and relieving the block and installing an aftermarket cam down there (to say nothing of the flex caused by those long pushrods and the rocker arms) could approach the VE, and the greater rpm capability of the smaller, lighter OHV and OHC engines becoming prevalent in Europe and elsewhere. I've had a chance to drive a few of these early 'hotrods' and although they're a lot of fun, I'm sticking with the Protege, at least for awhile. Although I wouldn't mind owning one as a second car. There are others, too.

        Sometimes, when I look at the history of automotive engine development, I ask myself is there anything really new under the sun aside from detail differences, improved metallurgy, and the more precise control of engine operating parameters made possible by electronics.

        Happy Motoring!
        Last edited by goldstar; 04-16-2010, 12:14 AM.
        02 DX Millenium Red - The Penultimate Driving Machine
        MP3 Strut Tower Bar kit; Cusco Front Lower Arm Tie Bar
        MSP Springs, Struts, Stabilizer Bars, Trailing Links, #3 Engine Mount
        Kartboy Stabilizer Bar Bushings; Nyloil Shifter Bushings; Red Line MT-90 Gear Oil
        MP3 Shifter, Knob and Aluminum Pedal Set
        Suvlights HD Wiring Harness; Osram Night Breaker H4 Bulbs; Exide Edge AGM Battery
        Summer: 5Zigen FN01R-C 16 x 7" Wheels; Yoko S.drive 205/45-16s
        Winter: Enkei OR52 16 x 7" Wheels; Falken Ziex ZE-912 205/45-16s
        Modified OEM Air Intake; Racing Beat Exhaust System; Techna-Fit SS Clutch Line
        Denso SKJ16CR-L11 Extended Tip Spark Plugs; Magnecor Wires
        Power Slot Front Brake Rotors; Techna-Fit SS Brake Lines; Hawk HPS Pads
        Red Line Synthetic Engine Oil; C/S Aluminum Oil Cap
        Cyberdyne Digital Gauges: Tach; Ambient Air Temp; Voltmeter

        Comment


          #5
          thats pretty cool actually good find
          live everyday like its your last!!!!
          90 DA9 project car
          93 BG2: daily beast

          Comment

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