Yamaha: YZF 600 R: Series versus racing version

Yamaha: YZF 600 R: Series versus racing version

Champions League

Supersport: This is racing with near-series motorcycles. But what does close to series mean? And what makes this hit so fast?

Hockenheim, small course. With 1.14.2 minutes, the standard Yamaha YZF 600 R scrapes around the course with sparking sparks.

Not a bad time. But with a YZF in Supersport trim, the same driver set a time of 1.08.2 minutes. Six seconds is an eternity on the small course. Where is the time lost? This alone cannot be explained by the additional output of 15 hp that the racing engine has compared to the series engine.

Sooner to accelerate, later to brake, more diagonally around the corner – these are the tricks for super-fast lap times. But in order to be able to use them in reality, the right conditions must first be created. The first and easiest step is to change the »tourist« ergonomics. The handlebars move under the fork bridge, the footrests move up and back, and the seat hump is padded. Bent over like this, you can hide completely behind the flat windshield.

Despite the very strict regulations in the Supersport class, which are supposed to keep costs within tolerable limits, a lot of further modifications to the basic machines are possible – and necessary. Using the example of the Yamaha used by the author in the DM, the difference between series and racing version can be demonstrated. When building the racing version, the main aim was to develop the positive characteristics of the series machine, such as the best torque and good-natured handling, and to optimize the weak points such as the spongy chassis design and the speed-reluctant engine.

Which obviously succeeded. His colleague Matthias Schröter comes to the pits sweaty but happy on the Supersport-YZF. “Now something is becoming clear to me,” he says, enthusiastically explaining how easily the racing version tilts, how precisely the brakes can be adjusted, how the chassis simply smooths out the deep waves in the north curve and how powerfully the engine hangs on the accelerator. The only thing the Laaks-YZF has in common with the production motorcycle is the name. But the colleague is not quite right about that.

The frame, swing arm and fork are standard parts for the chassis. Only the inner workings of the telescopic fork may be changed. Harder, progressively wound springs and tighter damping settings are the first step towards reducing the stability problems of a series machine. At the rear, the series suspension strut gives way to a complex Techno-Flex component. Now a fine hand is required to vote, and the Supersport-YZF is pulling its course like a string. The rear of the vehicle is around three centimeters higher than the original in order to make it even easier to turn in and to prevent the exhaust, fairing or engine cover from touching down too early. A welcome side effect: This reduces the steering head angle and caster, which also benefits the maneuverability.

Only 191 kilograms of weight, almost ideally balanced in a 50 to 50 percent ratio, and super sticky racing tires do their part to teach sports tourers the necessary maneuverability. Nevertheless, due to their heavy steel frame, all SSP-YZF are still around eleven kilograms above the permitted minimum weight of 167 kilograms (without gasoline). Aluminum or titanium screws are prohibited according to the regulations. The super-light titanium exhaust from Termignoni is just the famous drop in the ocean.
But it provides the appropriate acoustic background when the racer fires from the corners with the front wheel slightly raised. The fact that the four-cylinder reacts spontaneously to the slightest movement of the throttle is mainly due to the four-cylinder’s low flywheel mass. The crankshaft has been lightened by 1.2 kilograms and the 2.8 kilogram alternator has been dispensed with entirely. Instead, the series battery takes over the power supply for the ignition and fuel pump during the 30-minute race.

In terms of top performance, there are certainly engines in the Supersport DM field that have more than the 113 hp measured here. Excessive performance is slowed down by the strict SSP regulations, which, in addition to using the standard carburetor, also determine the valve lift according to the values ​​of the standard engine. Nevertheless, the hands of engine tuner Theo Laaks from Kassel are not completely tied. The experienced Yamaha expert increases the valve timing as far as technically possible, optimizes the flow of the ducts and his closely guarded details in the fine machining ensure that the decisive bit in the hard-fought supersport league.
A wide usable speed range is at least as important as maximum power. The YZF feels particularly at home on tight courses like in Hockenheim or Colmar Berg. Thanks to the harmonious use of power of the YZF motors, you can easily apply the throttle early and accelerate from a full lean angle. Wild slides due to sudden onset of performance are alien to the Yamaha pilots.

In order to use the maximum performance potential, the Yamaha engine needs a water temperature of 70 degrees. If the digital display climbs above 75 degrees, the sensitive racing engine loses two to three horsepower. Therefore, instead of the small series cooler, a large, curved YZF 750 cooler is installed. There is no thermostat, the temperature is regulated by partially taping the radiator.

In racing, driving is mainly in the speed range between 9000 and 13,800 rpm. In addition, the electronic rev limiter of the kit ignition box protects the four-valve engine from self-destruction. In “special” cases, the engines can withstand up to 14,400 rpm for a short time. But such excesses are at the expense of durability and require a complete engine overhaul after 400 to 500 kilometers. An expensive and, last but not least, time-consuming fun. Even if Master Laaks cannot discover any serious damage during such a routine check, the engine is always re-stored and the sensitive valves and seat are reworked.
W.he drives faster, has to brake harder. No problem with the prescribed series brake calipers. Brake discs and pads, however, may be changed. The SSP-Yamaha is therefore equipped with thick cast washers. These guarantee a consistently brutal delay with the best possible control even towards the end of the race. Warped brake discs do not occur in the SSP racer.

In general, the YZF proves to be an extremely reliable vehicle. Nine DM races without the slightest defect speak for themselves. And if she survives the last test in Assen just as smoothly, the title could even be awarded as a reward. And that would not only please the editor-in-chief.

Costs and prices

Even if the regulations are designed in such a way that the costs are kept within reasonable limits compared to the superbikes, the Supersport 600 class is not for hobby racing drivers. Whoever wants to drive under the first 15 of the DM has to either dig deep into their pockets or need committed sponsors who are at least available with free material. The prices given below are to be understood as approximate prices and may vary depending on the supplier and motorcycle brand used. As a rule of thumb, however, a competitive supersport racer is at least twice as expensive as the basic motorcycle. The necessary working time, gasoline and tire costs as well as any damage caused by a fall are of course extra. Steel 5000 marksMotortuning (make crankshaft easier, edit channels, etc.) 3800 marksMaintenance 3000 marksCaring plus humps and brackets 1000 Marks large radiator 850 MarkFork conversion 500 MarkShock absorber Techno-Flex 1700 MarkHandlebar stub 350 MarkFootrest system 800 MarkTachometer 350 MarkShift lightning 350 MarkBrake disks and sprockets 1200 MarkChain steering set 350 MarkBrake disks 1200 Mark 1200 marks

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