Car gets very heavy and becomes slow once it touches ground

Unity Engine
1

Hi

im trying to create car movment for my game and iv tested it out on a flat plane what the car accelerates fast but then what I transfer over to my game and the track i have it becomes very slow I have no idea why. Im trying to work out if iv set something in the inspector wrong for the track mesh.

This is whats on the track inspector

2560×1058 443 KB

These are my wheel coliders

2560×1080 437 KB

Video of my problem

2

I looks OK but are you sure the box collider is not dragging on the floor?
Your spring setting may need to be stiffer too.