He was also one of the first Japanese drivers to compete in the 24 Hours of Le Mans endurance race, making his first start in 1973 for Sigma Automotive alongside his countryman, Hiroshi Fushida.

He was the last out of twelve riders classified,[2] yet he earned a special "Fighting Spirit Award" from the organisers of the event just for being able to run until the end of the race without quitting.

He signed a works driver contract with the Prince Motor Company, and entered the Grand Prix in the new Skyline Sport Coupe.

[citation needed] In 1965, Ikuzawa raced in the All-Japan Car Club Championship at Funabashi Circuit, driving his personal Honda S600.

[citation needed] Though his focus was now primarily on his new overseas challenge, Ikuzawa still returned to Japan every year to take part in the Japanese Grand Prix.

His privateer effort was funded through some of the first corporate sponsorship deals in Japanese domestic motorsport: Pepsi-Cola, VAN Jacket [ja], STP, and Bridgestone were among the major sponsors that signed on, along with driving apparel company Racing Mate, which was established by Shikiba (now retired from racing) and former driver Tokudaiji Aritsune.

During qualifying, Ikuzawa became the first driver ever to lap the six kilometre Fuji Speedway under two minutes and secured pole position.

In the race, Ikuzawa recovered from an early incident with the Nissan of Kunimitsu Takahashi, then overtook the rival Porsche 906 of Tadashi Sakai to capture the lead again.

Ikuzawa returned for the 1970 JAF Grand Prix at Fuji in the upgraded Colt F2D, but once again, he retired from the race due to a mechanical issue.

With dignitaries including Prince Takamatsu in attendance, Ikuzawa was selected to recite the pre-race oath on behalf of the drivers.

Instead, he refused to take the oath, and voiced his discontent with the Japan Automobile Federation (JAF) and their treatment of Japanese drivers over participation fees and travel expenses.

[8] Ikuzawa signed a contract with Stirling Moss' Motor Racing Stables team to compete in the British Formula Three Championship in 1966.

Ikuzawa was nominated as a reserve driver for the Porsche System Engineering works team in the BOAC 500 Miles at Brands Hatch.

Ikuzawa's first F2 campaign with GRD was filled with growing pains: He either failed to qualify or was eliminated during the heat stage three times, and finished no better than ninth (twice, at Hockenheim and Mantorp Park).

Some time after finishing a season-best eighth place at Mantorp Park, Ikuzawa decided to stop racing in Europe.

That same year, he drove a Porsche 917K owned by David Piper in the final round of the new Fuji Grand Championship Series.

[11] In 1977, Ikuzawa put together a consistent season to win the Grand Champion Series title by a single point over Kazuyoshi Hoshino.

Team Ikuzawa was also involved in motorcycle road racing, winning the 1989 Suzuka 8 Hours with riders Dominique Sarron and Alex Vieira on their Honda RVF750.

He entered the 1979 race in a Mazda RX-7 alongside Yojiro Terada and Claude Buchet, but their car failed to qualify by less than seven tenths of a second.

He recruited former Williams manager Peter Windsor and former Lotus designer Enrique Scalabroni to help establish a new prospective Formula One team.

[14] The Ikuzawa F1 team was preparing to enter the sport by no later than 1998, and evaluated the likes of Kenny Bräck and Gil de Ferran as potential driving candidates.

However, Ikuzawa's prospective F1 entry never materialized as the result of financial difficulties, brought on by a slumping Japanese economy in the wake of the Great Hanshin Earthquake.