When the news came out that the Wachowski brothers would be doing a live-action film adaptation of Speed Racer, I wondered how they would go about taking the original source material and condense it down to a roughly two-hour long film. My interest was especially piqued after hearing that the Wachowskis are fans of the original series.
After watching the live-action Speed Racer, the first thing I realized is that more backstory was given for some of the characters, while others had backstories that were just as unknown as in the original anime series. In the live-action film, Mom Racer was actually given character and a personality. In the original anime, Mom Racer was basically just "there," and would only say something about how dangerous something was.
There is also a backstory for Speed and Trixie in the live-action film that doesn't exist in the original anime. In the live-action film, Speed and Trixie have known each other since childhood. The character of Sparky is still a mechanic who works for Pops Racer, and his relationship to the family is rather unclear in both versions. However, in the live-action film, Sparky is portrayed as being older than Speed; in the anime, Speed and Sparky are definitely in the same peer group.
In other instances, the backstory was changed between the anime series and the live-action film. In the live-action version, the story of Rex Racer's disappearance changed. In the anime, Rex simply disappeared and no one knew where he was. However, in the live-action film, everyone thought that Rex had died in a car crash while he was in a race. In the anime, no one knew Racer X's true identity; in the live-action film, Inspector Detector knows that Racer X is actually Rex Racer.
The backstory for Speed's car, the Mach 5, also changed in the film. In the live-action film, the Mach 5 was originally Rex Racer's car, and Rex left the key with a young Speed when he left the Racer house
Also, in the live-action film, all the gadgets that enhancements that the Mach 5 is known for are added by a third party after Speed starts his racing career. The jacks that the Mach 5 uses for jumping are a little different in the live-action film; instead of causing the Mach 5 to jump straight up and over an obstacle, the Mach 5 not only jumps, but it does turns in the air before landing. Personally, I thought this change was rather unrealistic. The live-action film also introduces the Mach 6, a car the Racer family builds during the film; the Mach 6 did not exist in the original anime series.
There are some other differences between the anime and the live-action film. While the anime is clearly set in the modern time for the era it was produced (the late 1960s), the live-action's time period is much less clear. While the Racers' house and clothing look like they would be from the 1960s, and a scene exists where a rotary dial phone is being used, a lot of the cityscape establishing shots that appear in the film look very futuristic.
In the anime, Pops Racer was very adamant at the beginning of the series that he didn't want Speed racing at all. In the live-action film, Pops is supportive of Speed's racing, until Speed wants to enter the race that Rex was killed in. Another change between the anime and live-action is how Racer X approaches his identity with Speed. In the anime, Racer X doesn't give Speed any kind of an answer. In the live-action film, Racer X tells Speed that Rex is dead. And I don't know how the Wachowskis managed to accomplish this, but Spritle and Chim-Chim are even more annoying in the live-action film than they ever were in the anime series.
While the live-action Speed Racer isn't necessarily a bad film, there's definitely a lot of differences between it and the original anime series. After watching the film, I think that overall, the Speed Racer anime series is better than the live-action film.