Cars: Weight Transfer & Body Roll

[Reed]

As I've learned from the "Physics of Racing" series by Brian Beckman, weight transfer of a car during braking can be determined by the acceleration, height of the car's center of gravity, length of the car's wheelbase, and weight of the entire car.

Now I realize that changing the spring rates will change the amount of body roll due to the intertia of the car's center of gravity. But the formula mentions nothing of spring rates, so I assume no matter what the spring rate, the same amount of weight is transferred from the rear wheels to the front wheels; and that's hard to picture.

Any ideas on this?

 

[Fuego]

the higher the spring rate, the more force is required to make the body travel relative to the wheels. so for a given force, the body will travel less relative to the wheels if the spring rate is higher. the more the body travels, the greater the weight transfer, so i don't see how spring rate cannot affect the weight transfer under acceleration/deceleration.

 

[BoulderHead]

I had stumbled onto an interesting link sometime back. It had a lot of demo software to perform various calculations and I thought for what it is worth I'd provide a link for anyone intersted to vist. Here is a snip;

"Computer Program to Simulate and Analyze Rear Suspension 4-Link Setups for Instant Center, Pinion Angle and Driveshaft Angle Change, Anti-Squat %, and More for Drag Racing"

Here is a link to their download section;
http://www.performancetrends.com/download.htm

 

[Doc]

Originally posted by Fuego
the higher the spring rate, the more force is required to make the body travel relative to the wheels. so for a given force, the body will travel less relative to the wheels if the spring rate is higher. the more the body travels, the greater the weight transfer, so i don't see how spring rate cannot affect the weight transfer under acceleration/deceleration.

Kind of depends on how the suspension is set up. A 4-link suspension with coil springs will behave diferently than a leaf spring for example.