The Most Dangerous Race (Part 2)
Speed is competing in the Big Alpine Race. At a checkpoint, an official warns Speed of impending bad weather. Meanwhile, fearful that the Mach 5's brakes will fail, Sparky, Spritle and Chim Chim set out to reach Speed with new brakes. Something "goes wrong" with Sparky's car. Luckily, Trixie rescues them in her helicopter. On an icy road, Speed tries to pull ahead of the Car Acrobatic Team. The team thwarts Speed's attempt by knocking down icicles. Rounding an icy curve, the Mach 5's brakes fail. The car spins out of control and slides down the mountainside. Speed radios Trixie for help. The next morning, Speed catches up to Snake Oiler, whose car, along with others, is stopped at the most treacherous part of the course. Because of heavy rains, any car attempting to jump over the cavern would be sure to cause a landslide. The drivers decide to draw lots. Speed jumps and joins the wreckage below.
Aired 21/10/1967EP 10 - The Most Dangerous Race (Part 2)

Speed Racer
The Mach 5 is one of the fastest and most technologically advanced race cars built by man. Equipped with various gadgets and a powerful engine, it provides a challenge for anyone who would dare race against it. The driver of this amazing vehicle is Gou Mifune, a teenager who dreams of breaking into the world of professional racing.
In spite of this, Gou's father and the creator of the Mach 5, Daisuke Mifune, does not want his son anywhere near a racetrack. Undeterred, his girlfriend Michi, younger brother Kurio, and Kurio's monkey sidekick Sanpei become Gou's biggest fans as he sets out to become the greatest racer of all time.
However, Gou soon learns that becoming a professional racer is not easy. From the underhanded plots of corrupt businessmen to stiff competition in the form of his rival, Racer X, Gou faces many obstacles on the road ahead, and has a lot to prove before he can cross the finish line.
(Source: MAL Rewrite)