The 58-second mark shows the power of the R35-specific tires

In parallel with Nissan’s ‘Tsukuba Circuit Fastest Time Challenge’ for the 2024 GT-R NISMO (MY24), Sumitomo Rubber Industries (Dunlop) conducted a time attack using its flagship tires scheduled for release in 2024. The new SPORT MAXX tires, in which all the technology and knowledge currently available, were used, ran in the 58-second range, faster than the genuine OE tires. We take a closer look at the secrets behind this.

Cornering performance improved by 7% with profile and compound

Dunlop has been working with the R35 GT-R for over 20 years, including the early stages of development. The new R35 GT-R has met Nissan’s strict requirements for a run-flat structure that is safe, stable, and quiet even at 300 km/h. The new R35 GT-R has a run-flat structure that is stable at 300 km/h and quiet at 300 km/h. In addition, Dunlop has repeatedly made updates in line with the evolution of the R35 and has supported its footwork.

The “SPORT MAXX” replacement high-grip tire for the R35 GT-R, which was unveiled at the Tokyo Auto Salon 2024, is the ideal sports tire that the development team envisioned and the core technologies accumulated through GT-R tire development and other activities. It is a flagship tire for the next generation that embodies the core technologies accumulated in the development of the GT-R and the ideal sports tire envisioned by the development team.

“The development started when the new Michelin Pilot Sport ‘Cup 2R’ was officially adopted by the Porsche GT3RS in 2019. At the end of 2019, we recorded the fastest time of 59.361 seconds for a mass production car at Tsukuba Circuit, but felt threatened by the new Porsche x Michelin package, We planned to compete with the new tires here as well.”

said Hiroyuki Uno, who was in charge of development. The initial goal was to defend the fastest speed for mass-produced cars, but eventually, the goal was settled on “to create a flagship tire that is the best premium and sports tire on the market by making full use of our technologies and knowledge”.

The features of this tire are the “road-following block shape”, which equalizes the pressure on the contact surface more than the compound/pattern, and the “new shoulder shape”, which provides maximum grip even when the tire is twisted, such as during cornering, and the “shoulder”, which prevents the outer steel wire from opening even when driving at 300 km/h. The “high-tensioning of the shoulder band”, prevents the outer steel wire from opening even when traveling at 300 km/h.

“Because it is not a specialized type like an S tire, but in the category of general commercial radials, we focused on giving it the highest all-rounder performance as a sports tire. Through the latest analysis technology and repeated demonstration tests, we have developed a new profile (shape) that focuses on not dragging the tire where understeer occurs. This ensures that the tire reduces evenly even after continuous laps on the circuit, which leads to a long life. In addition, a new structure has been adopted to pre-tighten the outer steel belt, which can cause bursts at ultra-high speeds, thereby reducing the risk of problems. Because what tire manufacturers want more than anything else is peace of mind and safety.”

This improvement With this evolution, the internal structure had to be changed and the mold/molding machine was completely redesigned.

“To be honest, the more we make, the more we lose, but it’s great that we can put that know-how into the new tires we will launch in the future. If we can get even in that area, we’ll be able to ….”

Incidentally, simulations have shown that cornering force has been improved by 3% for the compound and 4% for the ground contact improvement, for a total of 7% improvement over the GT-R’s OE tires. The effect of this improvement was also evident in the actual time attack. The vehicle’s attitude exiting Dunlop Corner showed a greater amount of roll and faster cornering speed compared to the vehicle with stock tires.

“The high grip and the resulting load on the transmission seemed to cause a slight tendency to slip during continuous laps. This can happen in a tuned car, but this was my first experience with a completely stock car. I also felt that there wasn’t enough power.”

“It was the first time for me to experience this in a completely stock car,” said racing driver Akira Iida, who was in charge of tire development and time attacks.

After a few laps, the team recorded a time of 58.820 seconds, easily exceeding the time set by the stock OE tires. The high potential of the tires was demonstrated.

The release date has not yet been decided, but we have been informed that some sort of announcement will be made in June, when the new SPORT MAXX RS model goes on sale. We await with anticipation.

translated by DeepL