G-Force: Understanding High-Performance Motorsports Dynamics.pdf

Excerpt Summary from "Making Sense of Squiggly Lines"

This excerpt from Christopher Brown's book provides detailed insights into using G Force Long (GFL) data to analyze braking performance in racing cars, both low and high downforce.

Key Takeaways:

GFL indicates Braking Effectiveness: Negative GFL values during braking indicate the car's deceleration force. The lower and more negative, the better the braking.

Speed & GFL Relationship: Speed directly influences GFL. Graphing both GFL and Brake Pressure together can provide complementary information about braking performance.

Low Downforce Braking:

Sedans with low downforce experience a relatively flat plateau of GFL during straight-line braking, followed by a rise as trail braking begins.
Entry speed into turns influences maximum negative GFL. Turns with higher entry speeds generally have lower maximum GFL.

High Downforce Braking:

Race cars with high downforce exhibit varying GFL values even while straight-line braking due to increased grip at higher speeds.
Maximum GFL before trail braking is proportional to entry speed. Trail braking reduces tire grip, leading to a sharper rise in GFL.

Braking Point Comparison:

The GFL trace effectively highlights changes in braking points between laps.
* Variance channel (representing speed change throughout the braking zone) helps quantify time gained or lost due to braking point variations. Even small shifts can result in significant lap time improvements.