There are lots of race horses the most famous perhaps; Sea biscuit a small throughbreed who won loads of flat races. Red Rum a world famous race horse who was a bay gelding. Hidalgo a small American mustang who won over 60 long distance races during his life time, after that he was let free to run wild buy his half American half red Indian owner Frank Hopkins.
no
It would probably be a registered [insert breed here]. Thoroughbreds are the most common breed of racehorse, but Arabians, Quarter Horses, Paints, and Appaloosas all race as well.
Shergar of Ireland
John Henry
Kruddler
After racehorse secretariat
If a racehorse and car are going 50mph they would both be going the same speed.
Racing Plate
I would say brown...
A steeplechaser
Man o' War
The best racehorse ever would be Man O' War and that's not just an opinion he was voted the number 1 (out of 100) best racehorse in the 20th century if you don't believe me look it up on his wiki.