Motorsports Standard Atmosphere and Weather Correction Methods
By Patrick Hale
70 pages

Kind of a long title but basically it's Everything you ever wanted to know about weather and racing.

Patrick Hale is the inventor of one of the first "what if" programs, the popular Quarter Jr and the Density weather tuning program. He has now written the definitive book on weather and race cars.

Did you buy a fancy weather station but always wondered what all that stuff meant?

Could you do a better job of tuning if you knew what all that stuff meant?
Are you a glutton for punishment and want to know all the math behind those programs?

It's all in this book. Just look at the Table of Contents below. Clear explanations of every part of weather and how it relates to tuning. Every bit of math is also in here so you can make up your own spreadsheet if desired. Works with gas, alcohol or nitromethane! There's even quite of bit of information on adjusting (correction factors) for things like weight, aerodynamics, track temps, down hill race tracks, etc.

 

Why did he do this since you can create your own Density program with the information provided? Because he can and plus no one has ever sat down and put it into perspective relative to race cars before. Sad but true. We have all seen bits and pieces in magazines but they often didn't agree with each other and confused us even further. I suspect that there are very few individuals that grasp every part of weather versus racing and it's importance. Patrick Hale is one of them.

 

The book is a good read, written clearly and in racing terms. I read through it again last night and finally know why I could never get my density altitude calcs to match his exactly. There are many methods and no one seems to agree, including airplane people. Now it's finally all in one place with sample calculations to guide you.

Table of Contents
Variable Names and Descriptions
Standard Constants
Calculated or Derived Constants

Chapter 1 - Introduction

About the Author

About the Book

 

Industry Standards

Standard Air Density at Sea Level

MSA Charts

 

ISA Temperature Definition

MSA Temperature Definition

MSA Temperature Table

Practical Advice

 

Perfect Gas Law

ISA Pressure Definition

ISA Pressure Table

MSA Pressure Definition

MSA Pressure Table

 

Altimiter

Track Elevation

Barometer

Corrected Barometer

Practical Advice

 

Air Density Index for Dry Air

Air Density Index (complete)

Density Altitude Equation

Density Altitude Table

 

Three Devices for Measuring Water Vapor Content

Describing Water Vapor Content

Relative Humidity Chart

Saturation Pressure Formula

Real World Mathematical Weather Examples

High Water Vapor Content Example

 

The "Problem" with Density Altitude

HP Correction Factor

Sample HP Correction Factor Equation

Definition of Theta and Delta

Comprehensive Weather Examples

Practical Advice

 

Sample HPC Equation for Methanol

Sample HPC Equation for Blown Nitro

Other Weather Correction Factors

 

Dragstrip Dyno

ET Correction Methods

MPH Correction Methods

Weight Correction Methods

Combined HPC and Weight Correction Methods

Dragstrip Dyno Update

 

Downhill Racetrack Correction Methods

Track Temperature Correction Methods

 

Aerodynamic Drag

Head Wind Correction Methods

Other Wind Angle Correction Methods