As we return to Richmond for this year’s final NASCAR iRacing Series race and bring to a close this season’s “Open Garage,” I thought I might use this week’s article to review some of the basics we have learned over the past 20 weeks. We have covered a myriad of ways to diagnose handling issues, increase our speed and analyze the information we gather in an effort to identify elements of our setups we might improve. In this edition I would like refresh your memory concerning some of the most common changes you will make.
Among the first topics we discussed this season – and one of the most common adjustments you will make in a stock car – is the track bar. To summarize, in the left rear if you lower the track bar you will loosen the car on exit and tighten the entry. If you raise the left side of the track bar it will have the opposite effect. In the right rear if you lower the track bar you will tighten the car on exit and loosen it on entry. Again, raising the track bar will have the opposite effect. If you raise the entire track bar as a whole you will loosen the car, if you lower it as a whole you will tighten the car.
Tires are a great place to fine tune your setup. It is important to be aware of the information provided concerning the temperature and wear on your tires. Knowing how to analyze tire temps and wear can help you make the correct adjustments to your suspension to reduce wear, increase grip and evaluate the best strategy for tire changes on pit road. While I will not go into each and every adjustment again, I will convey my thought process concerning tires:
For better grip the tire with a higher load should have higher pressure. Keep in mind that on a bumpy surface too high a pressure can cause the car to lose traction and break loose. Higher pressures overall will make the car more responsive while lower pressures will have the opposite effect, making the car feel sluggish.
Another topic we discussed was weight distribution and spring selection. We learned that softer springs, combined with more front weight and shock adjustment, will not only increase front grip but will allow the car to sink when cornering, thus “sealing” the front splitter to the pavement and allowing more air to affect the spoiler. This provides additional rear downforce, therefore increasing the amount of grip the car will have overall in the turn. Moving the weight forward will tighten the car through the middle of the turn and on exit while moving the weight back will loosen the car on mid-corner and exit.
Camber can have an immense effect on both cornering and straights as it controls the amount of tire contacting the surface of the track. In theory , more tire contact with the pavement provides better cornering while less helps increase speed in the straights. You will want to monitor your tire temperatures as the amount of camber has a great deal to do with the difference in temperatures over the surface of your tires.
Controlling your car’s oil and water temperatures is another critical area we focused on. We learned how adding tape and increasing the gear ratio will bring up your temps, giving you either better speed through increased aero or more response to the rear end from the throttle. Use tape to control water temps and gear ratio to control oil. I try to stay below 135* C on my oil and 130* C on my water to prevent damage.
While we cannot cover all of the sim racing topics we discussed over the past 20 weeks, knowing the major areas to adjust will go a long way towards understanding how adjusting each part of the suspension affects the overall performance and handling of the car. Having a working knowledge of the adjustments will help you to make educated decisions on where best to make your adjustments. I suggest finding a good setup guide or “Cheat Sheet” to help you; they are available in many places on the internet.
Thanks to iRacing News for their support throughout the season and to everyone who stopped by the forums to try out the sets and lend their advice. While my intent was to help some of the newer drivers learn the basics, I have also learned a lot myself. We hope to see you around the garage next season!
Good Luck and God Speed!