Racecars have very little ground clearance because they drive on very smooth surfaces.
The jack daniels V8 stooper car has 57mm of ground clearance, I expect they might bump this up for street circuits. (Road circuits like Albert Park were resurfaced to make them smoother before being used as a race track).
To maintain the best control over a rough surface the VW Polo World Rally Car raises their ground clearance by 95mm when they go from Tarmac to Gravel.
If you reach the end of your suspension travel while the car is pitching and/or rolling it will start to lift tyres and loose traction.
See how a rally cars wheels hang down? They're trying to ensure the wheels contact the road no matter how much the car is bouncing around on the road surface. Obviously they reach their limits once the car is this airborne.
As a comparison V8 supercars don't need the same amount of travel
You can set up your suspension to grip like a V8 supercar on the track but you'll probably reduce your amount of grip when you hit a rough patch of road or get the car really out of shape.
