After hitting 385 km/h with a supercharged H2R at the end of 2015, TRICK STAR has started a project to reach 250 km/h with the ZX-25R. But this time, TRICK STAR replaces the supercharger with a turbocharger to tackle unexplored territory!

TRICK STAR representative Ryuji Tsuruta, who has an extraordinary desire for maximum speed, continues to challenge himself, setting a world record for an electric motorcycle of 329 km/h (204 MPH) in Bonneville, USA, in 2019, even after he marked 385 km/h on the H2R in 2015.

The next target he chose was Kawasaki's ZX-25R, and he began tuning it to reach 200 km/h. The team did not modify the engine internals, but only the intake/exhaust tuning and computer settings, and during the shakedown test ride, the engine suddenly reached a meter reading of 202 km/h. The engine was then tuned to a speed of 200 km/h, which is the highest speed ever achieved by a ZX-25R.

At this time, TRICK STAR insisted on using the Japanese specifications as a base. The theme of the project was to achieve a performance level higher than that of the Indonesian version, which delivers 50 PS. To achieve this, a sub-controller was used to control the ECU and remove restrictions such as throttle opening.

In addition, the "TRICK STAR Racing Full Exhaust System IKAZUCHI," "TRICK STAR Power Intake Duct," and "Rapid Bike Racing Full Set TRICK STAR Specification" were developed and commercialized so that the parts can be actually purchased.

On November 20, 2020, TRICK STAR participated in the "MAX ZONE mini" held at Fuji Speedway outside of the prize competition and recorded its first meter reading of over 200 km/h on a 1.5 km straight. The actual speed was also marked at 195 km/h.

On May 3, 2021, at the Super MAX SPEED driving event held on the high-speed lap track of the Japan Automobile Research Institute, TRICK STAR rider Takehiro Yamamoto attacked, achieving a meter reading of 215 km/h and an actual speed of 205 km/h on the ZX-25R.

The May specification, which recorded the fastest speed without a turbo, delivers 45 PS at the rear wheel. The windscreen was made taller than STD to allow air to flow smoothly to the helmet. To further increase power, the engine's air funnel was changed to a specification that allows for more extension at high rpms above 14,000 rpm.

After achieving 200 km/h within about 6 months of development, TRICK STAR embarked on a turbocharged version. Tsuruta had been aiming for 250 km/h since the ZX-25R was first released, and in order to achieve this goal, he decided to use a turbocharger to increase power, just like Kawasaki, rather than tuning the engine internals.

Using the computer tuning know-how gained through the 200 km/h attack, the settings for the turbocharged supercharger were refined, and the stage was set for the first challenge at the 2nd Super MAX SPEED Run on November 18, 2021. With a boost pressure of 0.5 kg/㎠ and 58 PS at the rear wheels, the motorcycle ran at 225 km/h on the meter and 217 km/h in actual speed, breaking into new territory.

A month later, TRICK STAR again attempted to reach the maximum speed with a setup that increased rear wheel output to 71 PS. Expectations were high for a new record, but the result was a sluggish 226 km/h on the meter and 219 km/h in actual speed. In actual riding, the clutch capacity was not sufficient for the increased power, and the machine was unable to reach its full potential.

On March 21, the 3rd maximum speed attack using the turbo was conducted on the high-speed lap road at the Japan Automobile Research Institute. This time, boost pressure was increased to 1 kg/㎠, and the rear wheel output was successfully increased to 95 PS. The clutch, which had been a problem, was fully tested by adding one more plate and reinforcing the spring.

TRICK STAR's ZX-25R Turbo, on its 3rd test, is a 4-cylinder 250cc model that has been transformed into a monster machine with an engine output of over 100 PS, more than double the STD output.

The turbo uses exhaust air pressure to turn a turbine at the front of the engine, which also turns a turbine on the intake side on the same axis, thereby sending intake air pressure above atmospheric pressure into the engine. In this case, the boost pressure was set at 1 kg/㎠, which is double the atmospheric pressure.

TRICK STAR representative Ryuji Tsuruta performs a familiarization ride on the ZX-25R turbo. He also knows how to drive on high-speed laps.

Kawasaki is a manufacturer with a strong image of superchargers, including the "Hien" fighter plane. Mr. Tsuruta set out to develop the ZX-25R Turbo in this tradition. The ZX-25R Turbo is a dream mechanism, not only in the era of the 750 Turbo (left), but even today.&

The 3rd attack on the ZX-25R Turbo's maximum speed proceeded cautiously. In the beginning, Tsuruta watched the motorcycle to find the optimum boost pressure for actual driving. As he repeated this process, the speed gradually increased to 223 km/h (actual speed: 215 km/h) and 230 km/h (222 km/h).

At this point, the clutch began to slip, so Yamamoto replaced it with a new one and began his attack. In his first ride, he suddenly marked 242km/h on the meter (actual speed: 236km/h), and his speed entered a dimension where it was hard to believe that he was driving a 250cc machine anymore. However, the engine was almost completely blown out at this point, so he changed the driven sprocket to a 2T long.

However, this backfired and Yamamoto's 3rd attack saw his record drop to 241km/h on the meter (actual speed: 232km/h). This time, he changed the driven sprocket to a 1T short, and finally achieved 252 km/h on the meter (actual speed: 243 km/h)! A year and a half after the 1st attack, and about 6 months in the turbo, the challenge had paid off.

The on-board photos show that the engine speed has not reached the upper limit of 18,000 rpm, so it looks as if it could be extended a little more if the boost is increased. However, in order to take better care of the engine, the team decided to stop the test at this point and not achieve the final goal of 250 km/h actual speed.

The next test is scheduled for the 4th Super MAX SPEED Run on May 3. Before that, the ZX-25R Turbo will be on display at the Nagoya Motorcycle Show to be held from April 8 to 10, so be sure to visit the show.

On-board photo of the meter marking 252 km/h. On the tachometer is a GPS logger, QSTARZ, which measured the actual speed at 243 km/h. The tachometer is pointing around 17500 rpm.

TRICK STAR rider Takehiro Yamamoto attacks the ZX-25R Turbo. He is the first Asian Championship AP250 champion and excels in the 250cc class.

Members of TRICK STAR Racing finally achieved their goal. Tsuruta is in white, and Yamamoto is in black. Yamamoto, the 3rd mechanic from the left, has been a major force in the development of the machine.

For the March 21 test, a production-spec small turbine with reduced boost, commonly known as "Machine No. 2," was also brought in. To our surprise, the reporters were given the opportunity to test drive the ZX-25R turbo on the straight part of the high-speed circuit at full throttle.

My preliminary impression was that it might be quite severe to handle. I had thought that it would be a good idea, but there is no awkwardness in the 2nd machine, and it can start off just as well as a STD machine. There was no sign of any change in the lower rpm range, and it was almost impossible to tell if the machine had a turbo or not.

However, this changes drastically around 10,000 rpm. Power suddenly surges out of the engine, and the acceleration is about the same as that of a 400-500 cc engine. The feeling of increasing momentum as the rpm rises is similar to that of a 2-stroke engine, and it is quite enjoyable.

However, it is by no means an uncontrollable power characteristic, so you will have no trouble handling it even if you are not on a straight road. ZX-25R owners should check out TRICK STAR's turbo kit, which spices up the sound of this sensual 4-cylinder 250cc model to give it a more exciting ride.

The vehicle is equipped with TRICK STAR's turbo kit for the ZX-25R, which is expected to be released by the end of this year, although details are not available. It is neatly put together and does not look out of place.

It would be set up with a smaller diameter turbine than the 250 km/h version, so as not to sacrifice the normal operating range.

Test ride: I was able to fully open the throttle on a straight road over 1,500 m. It has 2-stroke-like power output characteristics, but it also has 4-stroke-like ease of use.

The power of the model 2 machine production is second from the top and delivers a whopping 72 PS at the rear wheel. This is truly 400-500cc class output. The top model is the 250 km/h specification, which delivers 95 PS to the rear wheel.

Sourse: japan.webike.net

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