BoT racing machines

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BoT racing machines

BoT racing machines
Thunderstorm

Werner Koch

07/11/1996

The Apocalypse has a name, or rather, a number: 916. The Ducati flagship was a real thorn in the side of the traditional fans in the BoT paddock, as the lightning-fast superbike won victories and championships in a row in a single, superior manner. The result: the tireless BMW and Guzzi drivers left their ohv twins, which were often lovingly pepped up, in the shed, the starting field shrank to the Ducati Cup, and interest in the Battle of Twins was gone. For 1996, the technicians of the Supreme Motorcycle Sports Commission, or OMK for short, came up with a formula that would alleviate the sickness of the 19 ?? should put an end to the existing class and secure the connection to the inferior, classic 2-valve engines (see box on page 44). How clever Ducati tuners keep the 916 Quadro-Valvole engine in good condition despite the technical limitations, is demonstrated by Ducati dealers and Team Vice World Champion ?? Ralph Bohnhorst. The engine, which has been increased to 955 cubic centimeters by means of Ferracci power units, pushes just under 140 hp onto the dyno roller. The conversion from electronic manifold injection to two 40 mm Keihin carburettors not only surprised with the top performance, but also with a full speed range and excellent performance characteristics. With which the superior one Ducati 916 is not quite as superior as before, but still fast enough to keep the rest of the pack in check. Because in addition to the powerful engine, the BoT-Ducati has other qualities. The race-proven and balanced chassis, for example. Or the already optimal aerodynamics as standard. A radical racing motorcycle that will continue to dominate the reformed BoT class under the rather unabashed throttle hand of Franck Schuller. Nevertheless, the second successful Italo team is quite satisfied with the new BoT formula. Jens Hofmann and his Jann Kramer-Guzzi with the air-cooled four-valve Daytona engine sense a chance to win again after years of overwhelming Ducati power. What looks like Guzzi from the outside has little to do with Guzzi. It is the work of the conspiratorial Hofmann troop, in which two 44 millimeter injection systems feed the 1160 cubic centimeter Nikasil cylinders with finely dosed fuel, in which Wiseco Hammer the pistons and Carillio connecting rods onto a stable crankshaft from Formula 1 supplier Cosworth. A massive 138 Newton-meter torque and impressive 135 hp push the 180-kilogram Guzzi out of the corners like a catapult. No wonder that Jens Hofmann occasionally finds the remains of his overused serial gearbox on the magnetic oil drain plug. But displacement is not everything. Larger valves are pressed into the expensive beryilium valve seats by a special spring made of hollow spring wire. Filled with cooling sodium, the valves on the outlet side avoid heat collapse, which is counteracted by 5.5 liters of well-tempered engine oil. At first glance, the central tube chassis also looks like Guzzi, but in reality it turns out to be a much more compact lightweight construction by the Berlin frame builders Melzow and Frose, which was completed with noble racing components. It is logical that the Kramer-Guzzi also eliminates unpleasant load change reactions via a torque support on the open cardan shaft. The bottom line is that the technical and financial effort of the Jann Kramer-Guzzi is no less than that of the unpopular 916 Ducatis. But the applause of the Italophile two-cylinder faction is certain for the current table runner-up. As the vanguard of Japanese BoT activities, Yamaha dealer Theo trusted me Laaks spontaneously connected his TRX 920. Not an easy game, especially since the brand new Twin has to be developed step by step towards performance and stability. But thirty years of racing experience of the Laaks team turned the standard TRX 850 into a fast BoT device that can be used to make great curves at the front. Theo Laaks squeezed 120 hp from a purely coincidental 916 cubic centimeter displacement and the carefully modified five-valve cylinder head. Feather-light slipper pistons, sturdy Carillo connecting rods and a tightly stepped six-speed gearbox from the YZF Superbike make the 175 kilogram TRX 920 a rookie in the 1996 BoT scene. No wonder that it has been reinforced with WP suspension elements and a superbike swing arm Truss tube chassis only put away the full punch after extensive test drives and coordination work without wobbling and egg dancing. The BoT-TRX 920 experiment has a welcome side effect for the Kassel Yamaha dealer: Just like Guzzi tuner Jann Kramer, Theo Laaks also produces an approved one BoT replica. The faction of the fast two-valve engines presents several variations on the theme of the Ducati 900 SS. The optics are strongly based on the production model, if Ducati dealer Jorg Jakobeit doesn’t want to stray too far from the base. Fine work on the engine and chassis and the attention to detail make the Jako-Ducati a feast for the eyes. Around 100 HP, supported by a sophisticated Ram-Air system, ensure respectable results for regular driver Wolfgang Bax, who will not contest all championship runs in favor of the Ducati Club races. Stephan Druschel, on the other hand, wanted to nail his head and is facing the battle for the BoT Cup on an Ilmberger Ducati. Weighing just 129 kilograms, it’s a real flyweight that has been knitted together with lots of love and even more carbon fiber parts. As part of the 888 Ducati, an around 110 hp 900 SS engine toiled, ventilated via two 42 Mikuni carburettors. Even at the first run in Hockenheim, the impetuous Stefan Druschel didn’t make a lot of fuss about the competition: second place, and thus the fastest two-valve racer. But just a few weeks later, horse and rider lay down in the gravel or sick bed. It’s a shame, Stefan, even Mick Doohan would be proud of your slides that are well worth seeing. The DSM team from Geislingen in Swabia acts much more consistently. Here, too, the 888 chassis spans the heavily modified 944 SS engine, which with its oblique flow ducts, dual ignition, Haltech injection and self-made camshafts generates around 110 hp. DSM driver Thomas Schuler holds up well at halftime on the ?? Place in the overall classification, and the trend is rising. And where is BMW? Calculated from the Bavarian four-valve boxers, nothing can be seen far and wide. And that, although the regulations are not just coincidentally tailored to the new 1100 engines. Or did you just overhear the starting shot in Munich in the jubilation for the new boxer?

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Thunderstorm

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BoT racing machines (technology) (archive version) – The Regulations of the Battel of Twins

With the so-called “two-out-of-three regulation” an attempt is made to create equal opportunities between two-valve and multi-valve engines. There are three basic designs to choose from, but only two of them may be used: 1.) water cooling, 2.) intake manifold injection, 3.) more than two valves per cylinder. There are generally no technical restrictions stipulated for two-valve machines; machines with more than two valves per cylinder, on the other hand, must have a minimum weight of 170 kilograms in any case. With water cooling, carburettors with a maximum passage of 40 mm are required, with air cooling an injection system with a cross section of up to 44 mm may be installed. Nevertheless, the new OMK formula is very controversial among drivers and tuners, especially since the decision on the “two-out-of-three rule” was made relatively late. A general ban on multi-valve engines was planned by autumn 1995. The targeted preparation and investments of some tuners and dealers on these regulations were therefore obsolete. Although the BoT Cup 1996 is held and evaluated jointly for A and B license drivers, the three best-placed B- cups are also awarded when distributing wreaths and trophies. Licensed young drivers taken into account.

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