Mach GoGoGo

I'll just keep this short. Both series deal with a young driver who drives an advanced racing car. With Speed Racer, it's the Mach 5 with it's gadgets. Future GPX Cyber Formula, it is Asurada, the most advanced computer enhanced race car. So as you can see, both are car racing animes that are 25 years apart. You could call the Mach 5 the grandfather of Asurada. 

I used to watch these together, Eightman first then Speed Racer as a kid because my mother loved to watch them when she was a kid. They were made around a similar time with similar ideas and goals in mind, just one was more successful at it. Both good quality time-capsules of what animation was like around the 60's, without being too boring or bland with some interesting angles and such. 

Oldschool vintage anime about racing - Machine Hiryuu is basically Great Value Speed Racer. 

Both are early, early pioneers of English anime adaptions. While they certainly haven't aged well by any means, they're an important part of Anime history.