Not always true,
Rubbing or scraping of the tyres against the inner guards at the rear can be overcome by lipping of the guards and/or negative camber at the rear. The need for either or both of these will depend on the width rims and tyres you have fitted and the off-set of the rims.
As fro braking, with a properly sorted out suspension the braking distances will be reduced.
The lower centre of gravity and stiffer springs at the front will allow the car to sit flatter and remain flatter during braking, therefore reducing the amount of weight transfer towards to the front of the car, thereby allowing the rear tyres to maintain a heavier contact patch on the road brakes to let them assist with braking more.
On a standard car with soft suspension and worn shocks, when you brake heavily the car nose dives down a lot, and with the weight transfer towards the front of the car the back will tend to lift and the rear brakes will lock up, causing the back wheels to skid. And a locked brake with a skidding tyre always takes longer to stop..
As long as your car's springs and shock absorbers are 'matched' and in good condition so that the shock absorber can cope with the demands placed upon it by the spring, then it will allow all four tyres on your car to maintain proper contact with the road at all times, improving the levels of grip under acceleration, cruising, cornering and braking.
It is when you fit lower (and heavier duty) springs to your car and the shock absorbers are in poor condition that it will cause the tyre to skip up and down when you jump on the brakes, hence adding to your braking distances.
It's about this time that Glen Seton will be jumping through your television asking you to check your brakes, tyres AND shock absorbers
Cheers
Bretton
www.PeformanceStylingCentre.com.au
