“The Story of a Man Possessed by Speed” RS Yamamoto・The Truth About Toyoshi Yamamoto【Play Back The OPTION】

Published : 2019/09/17 14:18 Modified : 2019/09/18 14:37

RS Yamamoto

The Legendary Max Speed Tuner

The truth behind the tuning genius, Toyoshi Yamamoto


Automotive tuning shop RS Yamamoto has been challenging Yatabe’s (high-speed test road of the Japan Automobile Research Institute, aka Yatabe) highest speed since the early 1980s. Mr. Toyoshi Yamamoto, the representative of the company, is praised by his fellow tuners as a recognized master of Nissans. He has greatly influenced innumerable young tuners without a doubt.


His sudden passing on March 27, 2011 seems like it was not so long ago. In honor and reminiscence of the man who was the forefront of the tuning world, we would like to recollect on his life through the article published in the January 1983 issue, “The Upcoming and Unerring Recreator: Toyoshi Yamamoto.”




<The Upcoming and Unerring Recreator: Toyoshi Yamamoto>

Japan’s Top Max Speed! A New Star Who Culminated His Craft


RS Yamamoto, Toyoshi Yamamoto


RS Yamamoto



To create Japan’s fastest car: a dream that every tuner has surely once had. RS Yamamoto’s Toyoshi Yamamoto recorded 290.32 km/h (about 180.39 mph) with his new Z equipped with an L-type turbo, surpassing RE Amemiya. With this max speed challenge, he succeeded in gaining all of the glory in just one year. Which leads us to wonder… who is this man exactly?



 A set of engine parts lays before our eyes.



“This here is the Z’s engine,” he pointed towards the engine block and cylinder head. This specific set of various parts in disarray on the floor was Japan’s fastest engine. Visually, there was nothing special about it.  The new Z’s CD value is about 0.37. Even with front and rear spoilers attached, it won’t cut 0.35. For a car with a CD value of 0.35, we calculated that we need around 350ps in order to set a record of 290 km/h. The rear wheel power output would be 350ps, which means the engine itself must reach around 400ps.


Up until a few months ago, no one knew about RS Yamamoto that was in charge of building this 400ps engine. Numerous tuned L engine cars exist in Japan alone. Furthermore, we know of around ten highly successful tuners who have attempted to be Japan’s fastest with an L engine. Among those famous tuners, RS Yamamoto did not stand out. Tuning solely for the purpose of standing out was a tuning taboo. Success overnight was highly unlikely. Only those who completed meticulous research and tedious work achieved a top rating in the tuning world. Nonetheless, after only one year of attempting the max speed challenge, RS Yamamoto was now sitting at the pinnacle of Japan’s tuning world with a domestic car.



RS Yamamoto



This new Z, with its 3L L-series engine + HKS Super Turbo carburetor that surpassed the 288.00 km/h (about 178.95 mph) record of the champion Amemiya Twin-turbo RX-7, was the first domestic car to hit the 290 km/h mark. RS Yamamoto had miraculously and instantaneously outperformed the other tuning legends, who all underwent a definite minimum of ten trials over the span of a few years. 



RS Yamamoto



Profile of the Man Who Shocked the Tuning World


RS Yamamoto is located in a corner of a residential area, about 100m from Kawagoe Kaido. Their size is closer to that of a garage, as opposed to an auto repair shop. Looking inside, you can see Airesearch’s T04B turbine, Solex triple carb, and HKS’s unique air chamber, etc. mixed with randomly scattered engine blocks and cylinder heads. Hangers and tools dangle on the walls, but the secrets of 290 km/h or 400ps are nowhere to be found.


“It’ll be two years since I started working independently,” Yamamoto started. He is thin in stature, with a longer crew cut and a sharp stare. It’s hard to believe that he’s a mechanic; he’d probably scold us if we said that he looks like he belongs in the nightlife. Yamamoto, now 33, was born on March 12, 1949 in Kagawa Prefecture. Apparently, he was a spunky troublemaker during his technical high school days in Kagawa. Yamamoto had his fair share of being no-good; he explored everything he wanted to try, including cigarettes, alcohol, and other paths.


One of those other paths included messing around with machinery. His first sacrifice was the bike CB72, which was his elder brother’s prized possession. When he got his motorcycle license at the age of 16, he sped around the country roads on this CB, paying no mind to what his brother thought about it. He proceeded with cylinder head portings, remodeling it to motocross style–mainly for aesthetic imitation. After high school, Yamamoto started working as a technician at a foreign-affiliated pharmaceutical company in Tokyo and used his first paycheck to buy a Yamaha AT90. At that time, motorbike racing was in its prime. With each magazine he read, he rebuilt his engine.



RS Yamamoto



“I was always crazy about reading and researching my resources–mainly reading books. I obsessively read the tuning articles and tried everything on my bike.” All of his paychecks disappeared because of this. In the following year, he received a used Bluebird 410 from a friend, built a Sunny B10, and then upgraded to a new Mazda Presto Rotary car. He began working part-time at a nearby auto shop during his free-time, and this eventually became his main occupation.


Yamamoto officially begins working with tuning after he was assigned to the Shikoku branch of that shop. “At that time, the current HKS and Sigma Automotive launched Japan’s first bolt-on turbo from the far east. It’s an L20 one-carb specification. Of course, I found it fascinating and I installed a lot of them in the customers’ cars. But it was definitely complicated. The only thing it got going for it was the word ‘turbo’ in its name, and it didn’t work well. There was always trouble with the electrical and plugs. I really wanted to make it better. I aimlessly researched and made countless phone calls.” At this time, he met HKS President Hasegawa. Mr. Hasegawa, who was thoroughly impressed by Yamamoto’s enthusiastic telephone interrogations, presented him with one of the first three HKS dealers.


With that, he was sent back to Tokyo. Despite spending about half a year away from tuning, he couldn’t forget the enjoyment. Yamamoto left the shop on good terms and moved on to a newly opened tuning shop called Sanbankan. The year was 1977. “I studied the most in those four years I was at Sanbankan. I liked the toughness of the L-type, and I tuned it constantly. Loaded the L28 on my Skyline C210 with my HKS street turbo and made my way to Ariake’s Zeroyon (quarter mile drag race) every week.”



The record is not a fluke. It’s a legitimate product of deliberate tuning.



RS Yamamoto



Yamamoto was personally incapable of compromise, and this was a good thing. He was not hasty. His tuning method was in pure experimental style, as done in a university laboratory.


“For example, you add CDI. Normally, you change the CDI, spark plug wire, coil, and plug altogether. I don’t like to do that. If you tune more than one thing at once, the real effect of the CDI is unknown. So, if it’s the first time, I only do the CDI. If the performance improves, I move on to the next step. If it doesn’t improve, I don’t include it. This is just one example, but really, this is how I do all of my tuning. I can’t do a lot of things at once because I’m not that clever.”


Yamamoto said that if he proceeded with his tuning and the power got stale or problems aren’t corrected, he reviewed everything from the beginning using each task data. For that reason, he kept a comprehensive record of changes and effects throughout the tuning process.


Yamamoto, who developed this unique experimental tuning at Sanbankan, became independent in December 1980. His customers from the Sanbankan era followed him, so he had no trouble business-wise. But for the first couple of months, he almost lost to his anxiety. Nonetheless, his own spunk and innate hatred of losing pulled him through.



RS Yamamoto



In the first year of opening, March 1982, Yamamoto challenged his first max speed run against the CARBOY Magazine shop. With his own Skyline C210+3L carb turbo specification, he set the mark at 248.28 km/h (about 154.27 mph). It recorded 13.27 secs even for Zeroyon. This was C210’s fastest to date (January 1983).


“I became obsessed with max speed challenges. Zeroyon is determined by factors other than engine power, such as body weight, gear ratio, and tires. But for max speed, if the body’s the same, it’s really all about the power. I did everything I could to increase power, since the one that outputs the most, wins.” In the Carpoint Magazine test in May 1982, with the old Z 2.9L carb turbo, he hits 248.28 km/h (about 154.27 mph). The champion of the L-type turbo at this time was OPT’s Z with a record of 263.73 km/h (about 163.87 mph), so for Yamamoto, it was still a second-class finish.


This second-class engine loaded on the old Z eventually achieved 400ps of power, but at this time, each part malfunctioning produced no power at all. Merely assembling the HKS super turbo kit straight on, no matter how much he changed the carb jet settings or engine settings, resulted in low power. “I thought a lot about it. If you limit the carb at a low rotation, you can’t get much power at high rotation. If you reverse it, you can’t use it on the street. And so I consulted with the owner of this Z to eliminate each issue.”


Ultimately, the first major change was to replace the car with a new one. The old Z showed traces of the electrical system being tweaked previously; the CDI fell flat no matter how many times he replaced it. The owner purchased a 2L new Z with the cheapest specs, which Yamamoto referred to as the Natural Z, and installed the same engine in it. The engine remained the same to keep the conditions consistent. With just a body swap, the power output greatly increased. The electrical was weak on the previous, as he had predicted. Stability largely increased because of the solid suspension settings and good aerodynamics. Next on the list was power-up.



RS Yamamoto



“The turbo’s air flow determines its power–how to evenly guide the air to each cylinder; how to set the appropriate fuel economy. Anyway, I thought about that from morning to night. If I came up with something, I tried it regardless. I got up in the middle of the night to work on it and go on test runs.”


This passion and knowledge had accumulated to an amount that we could not fully record, no matter how many pages there may be. There were dozens of things that convince you that his settings were indeed precise. Each setting and modification had a proper purpose and reason, and the test results were the fruits of his labor.


“It’s all common sense if you think about it. For example, if the amount of air entering each cylinder is different, the obvious result is a mix of cylinders with concentrated gas and those with more diluted gas. With fuel injection, the injected amount is the same. In that respect, carbs are great because fuel production is proportionate to the air amount. So that’s why I use the carb, but that’s not good enough. It’s all about how much you can equalize the air amount in the cylinders, and to do that, it required a lot of trial and error.”


He continued his advancements with tips and theories on how to assemble the engine body: the relationship between compression ratio, boosting pressure and ignition timing, combustion chamber shape, valve and valve seat, cam shape, engine block distortion, and boring methods. Turbine settings, chamber shape, carb modification, intake air flow rate, wastegate tuning–the list went on. Among them, there were rationales that we were familiar with, but there were also those phenomenal ideas that left us dumbfounded.



RS Yamamoto



Yamamoto was an extraordinary scholar. There was no doubt about it. He succeeded in boosting power with each precise setting. And with that, his new Z marked the fastest 274.80 km/h (about 170.75 mph) for an L-type turbo in the September 1982 Carpoint Magazine test.


Hirata (Z owner) recalled, “Every time he changed the setting, it got faster and faster. It was amazing. When he said that he tweaked something, we would increase around 10km/h in speed. Then he’d tweak something else, and we got another 5 km/h increase. In his pursuit for power, we were all of a sudden at 290 km/h.”


Yamamoto continued, “I don’t really feel like we’re number one in Japan. I’m sure that you can tell, but it’s not like we’re using any special parts for our engine. The turbine is an A/R 0.96 that we bought from HKS, and the cam and piston are domestic tuning parts. I was just really precise upon installing each part. So I could probably build as many as I wanted, and that being said, I think anyone could actually build them, really.”


Amemiya, who competed for Japan’s top max speed with Yamamoto, also said the exact same thing before.  Perhaps only those who succeeded in culminating their craft can afford to talk in retrospect. Although both of them took great pride in their work, they were far from conceit.



Max speed tests settings and specifications occupy Yamamoto’s entire mind. He plans to do another challenge after he lowers the final gear and increases the 5-speed gear ratio. From his work clothes pocket, we find his notes of the max speed calculated at each gear ratio. 5-speed 6000 rpm = 294 km/h (about 182.68 mph); 6100 rpm = 299 km/h (about 185.79 mph); and… Yamamoto’s tuning theory and practice is certainly approaching the 300km/h mark, which would be a first for Japan. Such a breakthrough is anything but just a dream. We eagerly wait to see how he performs for the full throttle challenge at the OPT max speed test on November 25, 1982!



RS Yamamoto



【From Option 1983 January Issue】



In his younger days, Yamamoto’s stern looks matched his stoic approach. But in his later years, he taught the younger staff members at OPTION Magazine about countless things, such as his life views and theories on tuning. He often instructed even the budding tuners from shops other than his own.


With utmost sternness, simplicity, and diligence–this was his way of tuning.


Toyoshi Yamamoto, a man who genuinely lived face-to-face with speed.