I'm trying to find the name of a scifi series, but can only remember scattered parts of it! It starts with the protagonist on a planet (possibly all alone) and he has no memory of the past. He builds his own spaceship using the parts of a crashed military ship, including the secret "black box" power-source/engine. His ship is able to go faster than any others.
A bit later he races his space ship in a huge race, possibly on Earth, definitely in the solar system, wins, and meets the immortal emperor and family.
His space ship is different from all modern ships, and I think looked like a current jet. The military is broken up into different forces with a lot of competition between them.
That's about all I can remember I think. I suspect the books were from the 70's or 80's, although not certain; I read it in the late 90's/early 00's. Help!!