This is a technique I found out a few days ago.
1. For this, you are going to have to make yourself a REALLY light machine because the others are too heavy. I built the Machine called 'Sky Dragon', made out of the lightest parts in the game. Once built, choose it for the race.
2. Set settings to Max acceleration.
3. Choose a course with a wide open space and will take you a while to get to the ground it you fall off the edge.
4. Drive off the edge.
5. Hold down R and hold your analog stick right so you will trace a thin line, eventually your machine will start slowly going upwards. Whilst doing this, do not hold your analog stick back or you will cause the machine to stall.
6. Once the desired height, let go of the R button and aim your analog stick down and try to aim towards the track.
It is posible to get over 4000 k/h with this trick.
I'm gone - bye