…gives up and helps him to win the race.
It is a 80’s or 90’s movie, probably direct to video. There is a fatal accident in a sort of Indy racing team during a test run. In order to substitute the pilot, the team hires a former genius mechanic that wants to try his luck on the wheel. His teammate immediately challenges him creating a big rivalry amongst them. The former mechanic is not really that good an often commits mistakes while switching gears, which lead to no great results on the track. I don’t remember much more, but in the end the mechanic prefers to stand down as a pilot and help his team mate by acting as a mechanic (he finds out a different mixture in the fuel can give him 10+ hp), which helps him win the race against a French pilot from another team.