OK I might be going overboard here but I have a question for the engineers and physics gurus out there.

So this whole section of the boards is dedicated to making your car handle better, and questions concerning that. As I look over all of these posts it seems that in general making your car stiffer--shocks, struts, subframe connectors, stb's, wonderbars, everything of the like--makes it handle better (maybe I'm a little off). So for the question--how, from a physics standpoint, does making your car stiffer help handling and control (some stuff on pitch, roll, maybe launch and suspension geometry might be in order too, not sure).

I don't know if it has something to do with like conservation of energy or just like momentum or something. In the end I just want to know WHY most people do the same thing to make their car handle better.

 

With a more stiff suspension the body has less tendancy to roll. As you know, if you make say a hard right hand turn you will feel the car roll to the left. When this happens, weight is shifted from an evenly balanced state to the left side. When this happens, the right side wheels get less traction.

I am not going into the steering aspect because I can't for the life of me remember the correct terms. Basicly when you make a right hand turn the front wheel look like this / / this combined with the body roll makes the tires ride perpendicular to the road giving the most traction.

Not a guru, but that should help.

 

There are roughly three parts to this.

1. Platform stability
STB's, Subframe connectors, spherical joints, door hinge improvement kits, roll cages are all attempts to make the
platform more rigid.

Rigid from a strict "handling point of view" is good beacause it
tends to reduce/remove a variable from the equation.

Think of a piece of pvc pipe... wave it around, it flexes, swing it hard towards a table and try to stop it .5 inches from the table.
Its takes a try or two beacause you have to compensate for the undamped flex of the tube.

Do the same thing with an aluminum tube and its a bit easier.

Same thing with the inherent flex associated with our cars.
Our cars act like an undamped springs. When you add in the
unpredictability of inputs like road surfaces and what not you get fairly complicated oscillations that make it tougher for a driver
do deal with.

2. Adjustability
Shocks, struts, springs, adj lca's, adj panhard rods are attempts
to adapt the car to its stated purpose. As you move a car towards
being better at something (drag racing, autocross etc) you find
that real gains can be had by adjusting the characteristics
of these components.

3. Tune
The particular "tune" you select (caster, camber, toe in,
ride height, corner weighting et al is closely related to (2.)
and is interactive. These settings dictate the behavioral
characteristics of the assembled package.

A reasonable description of this might go 200 pages

For a roadracing/autocross centric description of vehicle
dynamics try...

Performance Handling, Don Alexander,ISBN 0-87938-418-2

and...

Tune to Win, Carroll Smith, LOCCC No 78-73-549