The "Latest" Rig

The "Latest" Rig
Bodnar Wheel w HPP Pedals (Added Rift in Summer 2017)

Sunday, December 24, 2017

Basic Set Up Training for the iRacing FR2.0

Basic Set Up Training for the iRacing FR2.0


Intro

For the benefit of the iRacing FR2.0 “community” I will be sharing a series of articles.
This series of articles is not intended to impart every bit of race car wisdom ever discovered.   They are intended to provide a foundation of knowledge that will allow you to “build” a setup that will allow you to race at a reasonably competitive level as compared to others with similar physical abilities and racing experience.

I am a Mechanical Engineer who has studied vehicle dynamics for nearly 50 years.  Over the years, I have developed a reasonable level of competence as a racing driver.  However, I am far from being even close to the abilities of top rated drivers.  Whatever limited success I have achieved in racing has been due almost entirely on “building a faster car” through engineering and development.  So, think of me not as a driver coach, but rather as an experienced Crew Chief or Race Engineer. My goal is not to impress you, but rather to simply be a helpful resource to some. I really love the "sport" of iRacing. I hope this basic info makes the "sport" more fun for those that find it helpful. 

For the FR2.0, there are services that publish setups that have been tested by some really talented drivers. They provide great value to many, especially if coupled with one on one driver coaching.  I highly recommend the one on one coaching offered by VRS and Wyatt Gooden.(A great deal of my knowledge regarding the iRacing FR2.0 came as the result of Wyatt Gooden coaching.) I also highly recommend using the Youtube hot lap videos provided by Thomas Jordan. The Driver61 website by Scott Mansell is also an excellent resource.  But, no matter what resources you use, I submit that you will be a better driver, and will derive much more satisfaction from your racing activities if you understand the basics of how to setup the race car yourself.

Keep in mind, there is no “magic” setup that will allow every driver to become a champion, or even to reach their best potential.  Performance on the track is the result of the “combination” of driver and machine.  Since no two humans are exactly alike, the best setup for each will vary.  In fact, the best setup may vary significantly from one driver to another.

Driving a race car is all about managing forces—directly created by the driver, and those that result indirectly. Think “action” and “re-action”.  Optimizing these forces to achieve the fastest lap is the ultimate goal.

Before we get into specifics---I will introduce a very important basic concept: 

The Balanced Race Car

Every driver input, thru throttle, braking and/or steering introduces a force.  These forces (Engine Torque, Braking Torque, Tire Slip Angle each in combination with Tire Grip) directly produce acceleration, with either a change in speed or direction, or a change in both. Rolling Resistance, Inertia, and Aerodynamic Drag are “resistive” forces that are affected by the race car setup or design.  Resistive forces resist the change of speed and/or direction.  All of these forces are affected to some degree by environmental conditions, such as weather and track condition.

The Balanced Race Car is one that achieves the optimization of all these forces to produce the fastest lap. This “balance” is achieved by the optimum combination of driver input/s and car set up, given a certain car design and a certain set of track conditions.

The concept of optimization is simple to understand when there are only two variables—the concept of trade-off---benefits have costs.  For example: More wing produces more downforce which provides more grip, but comes at the cost of more aerodynamic drag which reduces acceleration and top speed.  The process of optimization is much more complex than the concept. Often the best result is achieved only through a series of experiments or trial and error. And, such experiments take less time if you know the generally expected cause and effect from your changes, and if you have a reasonable starting point.

Here is a simple graph of lap time vs wing angle.  Increasing wing produces more downforce and more grip allowing faster laps until the cost in aero drag begins to outweigh the benefits—you lose more time in the straights than you gain in the corners. There is an optimum setting. Notice that I did not trouble myself with the curve of downforce vs wing angle. That relationship is complicated by the fact that it is affected by speed.  (We will devote an entire article to wing and other aero settings.)

An important assumption of this optimization of wing is that the driver pushes the car to the limit of grip in the braking zone and throughout each corner.  Often, drivers will not do so in their testing and will not gain the maximum benefit from higher downforce.

Most variables are best optimized by direct testing of how changes affect lap times. The “balanced” race car is the one that is the fastest with a given driver under the given track conditions.

Many variables/settings can be optimized more quickly by using the driver’s feedback regarding how the car “feels” in corner entry, mid-corner, and corner exit.  Here the three simple concepts of understeer or push, vs oversteer or loose, vs neutral are important.  Adjustments can be made to the car and driver inputs to optimize the car’s handling—again the optimum being the combination that produces the best lap time.  In the case of most drivers, a car that understeers slightly on corner entry and oversteers slightly in mid corner and corner exit is both faster and more stable—especially in racing conditions with traffic.

Another caution. Often, the cause of a driver’s feedback comment is poor technique. For example, entering a corner too slowly and accelerating too early can often make a driver complain that the car is too understeery. Using VRS, iSpeed, or iAnalyze telemetry to compare the driver’s technique to others is useful in evaluating this.  

One “gauge” of being balanced is tire temperature.  Tire temperature is a proxy or “gauge” of cornering force. When the temps for the front and rear tires on the same side of the car are significantly different, it is often an indication that cornering force is not being optimized.  (This depends on the car to some degree—but for each car with a balanced setup there is an optimal relationship between tire temps for the front and rear tires on the same side of the car.)  If the front tires are relatively too hot, then the car has too much understeer and is wasting available grip and cornering force from the rear tires. If the rear tires are relatively too hot, the car has too much oversteer and is wasting available grip and corning force from the front tires.  There is one exception to this rule—in setting up a car for fast 2 lap qualifying or racing on a very cold track, it may be optimal to run a setup that tends more toward oversteer-if the driver is comfortable.  

If the tire temps are not in balance as mentioned above, the handling becomes progressively unstable on a hot track after a few laps as once the tires exceed a certain temp, they lose grip rapidly and begin sliding more, generating even more heat and temp. 

It may surprise some, but in real life, there is a lot less adjusting of the setup at the track than most people realize. Generally, almost every ideal setup for a given track can be derived by making relatively minor changes to one of three basic setups for a given driver.  So, the goal is often to produce those three basic (driver specific) setups and then use them as a starting point when making the final adjustments to achieve the balanced setup for a specific track and track conditions.

Future articles will cover more detailed info regarding:

Wings, Rake and Aero

Dampers and Springs

Differential Settings

Camber/Caster/Toe

Tire Pressure and Brake Bias

Asymmetrical Setups
















1 comment:

  1. Thank you, I am very much looking forward to the rest of the articles. I've been driving FR2.0 on iRacing for five seasons now and am in the top 100 participants. The setups I use come from the forums, other drivers and vrs. I feel like I'm at the point where my driving is consistent enough that making adjustments to suit my style is the next step in being more competitive.

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