1991 sees us enter the DTM, a racing as popular as F1 in Germany

Yasukawa recalls "The son of Domingos Piedade (then Vice President of Mercedes-Benz tuning division, AMG) was a kart racer, and through this he became friends with Ayrton Senna, who bragged about the excellent performance of his Bridgestone tyres. Mercedes-AMG was using Dunlop tyres on their machines in DTM (German Touring Car Championship) but they were searching for something better to give them an extra advantage. Hearing that we at Bridgestone were seriously committed to motor sports, Piedade decided to come to Tokyo and discuss things with us. I had just returned from Europe myself, when I heard that Piedade was here and wanted to meet. We discovered that we had many mutual friends, hit it off immediately, and decided to work together in DTM."
When Yasukawa attended a DTM race at Hockenheim at Piedade's invitation, he was amazed at the enthusiasm and huge size of the crowd that turned out to watch the contest between the different machines by Mercedes-Benz, BMW and Alfa-Romeo.
Returning to Japan and convinced that Bridgestone would benefit greatly from participation in this series, he immediately proposed a budget to then Managing Director, Akihiro Ono. Ono tried to put him off, saying "We don't have that kind of money available. I might get you half." Instead of being discouraged, Yasukawa instantly took this as authority to go ahead, using half his initial budget.
"I'm sure he thought his reply would make me give up" says Yasukawa. Instead, he quickly set the Kodaira Technical Centre to work preparing for DTM, despite the reduced budget.
Yasukawa saw the value of DTM to Bridgestone and firmly believed that, given the chance, we could succeed.

1992 - Once again, we taste defeat at the hands of Michelin

Bridgestone's years in DTM had a worldwide impact. In five years of racing with Mercedes-AMG (1991 to 1995) our team took three drivers' titles and four manufacturers' titles. DTM machines used narrower tyres than formula racing cars, and this made it difficult to develop tyres with the required performance to support these very fast and heavy machines. But we succeeded, evolving our tyre designs to beat the competition, and gaining extremely valuable experience in preparation for our F1 ambitions.
It was at the Nurburgring race in 1992 that Michelin once again taught us a bitter lesson. In conditions that were much colder and wetter than expected, the Michelin-shod 4-wheel drive Alfa-Romeo lap times were 6 to 7 seconds faster than ours. The Mercedes-AMG machines fitted with our tyres were front-engine and rear-wheel drive, which made them far more prone to skidding on the wet track than four-wheel drive cars. Even so, it was clear to anyone watching that much of the Alfa-Romeo lead was due to the better performance of their tyres.
Hamashima had just taken over as DTM race team leader. After the race, he and Yasukawa were summoned to the Mercedes-AMG motorhome where the angry team manager banged on his desk and declared he would switch to Michelin and Pirelli for the next qualifying round.
It was an almost exact repeat of the humiliating experience in the 1982 European F2 - the disgrace of being rejected mid-season in favour of another manufacturer's tyres. And once again, our disgrace was at the hands of Michelin. In fact, Mercedes-AMG switched tyres only for the qualifier - conditions for the actual race were dry and their cars won on Bridgestone tyres. Although we had a successful season overall, the Bridgestone Motorsport team never forgot this humiliation and it motivated us very strongly to make greater efforts.

Coping with trouble, we emerge stronger

We had been humiliated in DTM, but we were soon to have our revenge.
Bridgestone had a certain technology that was still being researched and refined - it had been proposed but not yet adopted for use. This new technology added silica to the compound. Today, this is the normal way to improve the grip of tyres facing wet, low temperature conditions, but at the time it was a completely new idea. The in-house proposal had been temporarily shelved until ways could be found to overcome manufacturing difficulties.
The motorsports tyre development staff embarked on a crash program to produce wet tyres with the silica compound just for DTM. A few races after our defeat, conditions turned wet again. And this time, the new tyres carried Mercedes-AMG to a resounding victory. We were especially moved by the praise from Klaus Ludwig after his win in the rain: "With these tyres, you don't need four-wheel drive."

DTM brings business to Bridgestone

"This is the strongest sales weapon we could have." That's how Gunter Unterhauser, then president of Bridgestone Germany Sales, described our participation in DTM.
AMG also helped us greatly. At that time, the Mercedes-Benz purchasing department was focused on rationalising and reducing its suppliers, and Bridgestone was among those it had eliminated. However, AMG continued to use our tyres. We faced other competition of course, but after AMG introduced us to Mercedes' commercial vehicle and other departments, the efforts of Bridgestone's direct and local sales departments secured access to Mercedes-Benz for our tyres.
We were greatly helped by Norbert Haug (now Mercedes vice president for motorsports) and by his superiors in Mercedes, including such distinguished names as Jurgen Hubbert and Dieter Zetsche. As Bridgestone-shod machines continued to rack up DTM wins, Mercedes top management grew more friendly toward us. The close relationships we formed in this period would later bear fruit in our second year in F1, when a McLaren Mercedes took the championship on Bridgestone tyres.

Firestone focuses resources on IndyCar and Indy Lights

When Bridgestone acquired Firestone, our then President Yoichiro Kaizaki declared that it was essential for Firestone to become more active in motorsports. This encouraged us to push the idea of IndyCar racing.
Yasukawa, strongly supported by Executive Vice President Harada, was proposing we enter F1 due to its worldwide scale, and Firestone had previous experience of F1 as well as IndyCar.
However, it was thought best that Firestone's return to major racing should be in their own country's top race. In other words, Indy Car racing. At the time, Firestone had an extensive system supporting a wide variety of minor motorsports categories. Bridgestone decided that it would be too great a burden to maintain this broad system as well, so all other motorsports activities were cancelled to allow the company to focus its strength on just IndyCar and Indy Lights.

1995 - Firestone supplies tyres to top IndyCar teams

Bridgestone Motorsport's Yasukawa decided that, if we were to succeed in Indy racing, we would have to start out working with the top teams.
Through a friend he had made in Mercedes-Benz during our DTM racing period, Yasukawa got an introduction to Roger Penske, the owner of the top Indy team. Next, he met Chip Ganassi, whose Indy team had just begun using Honda engines, and suggested that Ganassi ask Honda to fit Firestone tyres. After negotiating with Shigeo Watanabe, Bridgestone's top technology manager (later to be company President), Yasukawa got Bridgestone to agree to provide technical support, and we entered Indy racing from 1995. Firestone-shod machines began taking the championship from 1996, vindicating our policy of approaching the top teams first.

Indy racing - A tough new test for our tyre designers

After our experiences in European F2, Le Mans and DTM, Bridgestone Motorsport now had a solid racing organisation in terms of equipment and logistics. However, on the technology side the challenges kept coming and Indy racing presented us with a whole new set of problems to solve. After supplying tyres for machines in the Le Mans Group C sports prototype endurance championships, we were confident in our tyres' ability to stand up to 400 km/h high-speed endurance racing. The Indy500 was the world's fastest race, but the speeds were in the same range. So why did our first Indy test tyres immediately develop blisters?
We discovered that the oval Indy course, designed to maintain constant high speeds, put far more stress on tyres than the circuit races we had been used to. And in addition, the Indy machines were wing cars. The powerful downforce these cars created added a far greater vertical load when a tyre punctured and the lateral acceleration changed to longitudinal G forces.
This had not been obvious to us from the data we had collected to construct the test tyres, and was the cause of the blistering. Everything about racing in the US was new and unknown to us, even how to go about gathering the necessary technical data.

The Indy experience was vital in readying us for F1

We quickly moved to correct this issue, improving the heat resistance of the tread compound and our adhesive technology. We would never have discovered the need for these modifications if we had not taken part in Indy racing. Another great benefit from our Indy experience was the chance to learn from Goodyear, the rival tyre-manufacturer we would later have to face in the F1.
In 1995, when Firestone first returned to Indy racing after a 21 year absence, only five drivers used our tyres. Even so, we scored two wins that first season. Then in 1996, Indy car racing was split into two leagues, and in each of them the champion was carried to victory on Firestone tyres. As well as widely promoting the Bridgestone and Firestone brands throughout the US, this was another very important step for us on the way the F1.