Over the past few years, we've taken on various project cars with real-world, on-the-track testing, racing, and evaluation. We're involved in this so that you can see our progression and, hopefully, we can all improve on the processes involved in building, setting up, and racing a race car. I can honestly say that few of our projects have gone exactly as planned. However, we have had excellent results in being able to improve both the team's processes and success, as well as in the presentation of information to you, our readers.
In a perfect world, we would be there to observe and be in on every decision a project team makes and be a total part of that process. That's not always the case because in a lot of instances it's not practical. We have influenced certain teams and improved on their processes, and in all cases tried to steer them away from experimentation without evaluation. And that is our overall goal as a technical magazine.
This was our designed setup...
This was our designed setup for our first test at Concord Speedway in Concord, NC. We decided to go with a soft / conventional setup using a moderately stiff sway bar. We balanced the setup and went through the car checking alignment and security of bolts, and so on.
We don't own race cars and teams because there's no budget here for that. So, for the most part, the golden rule applies; those with the gold rule. We sometimes are content to sit back and observe for the most part, and the end result is telling you how a team either did things right or might have done things differently and done better.
Back in the day, when I was recruited by a team as a consultant, I made them understand that I was to be in total control of all aspects of the setup. That had to be how it was in order for me to properly evaluate the car and do what was right to make it competitive. Most problems come from a team using setup pieces and parts from other teams that don't necessarily fit the design of their car. One of our primary goals in doing project cars is to help teams refrain from doing that.
Keep in mind that this is a report. It uses test, practice, and race notes including driver comments, tire temperatures, lap times, and a record of changes made to the car. As you follow along, try to compare what is happening to how your team does things. There may be a few lessons to be learned.
Before you race, do a quick...
Before you race, do a quick and easy Ackermann check. You can use string or lasers. Project the wheel alignment out to 10 feet in front of the wheels with them pointed straight ahead. Make a mark on the floor (use wide masking tape). Then turn the wheels about the same number of degrees you would in the turns. Again, project the wheel alignment out 10 feet and make a mark. Then measure between the two marks.
The Plan
The team consists of driver John Gibson; his father and team manager Chuck; John's mom, Kristy, very active note keeper and timer; crew chief Justin Lages, from my hometown; car chief Josh Corbridge; media relations Erica Smetters; and junior engineer Adam Wall. We initially evaluated the car that was built by Steve Leavitt and determined a setup plan. I wanted to go with a soft, conventional setup that would provide positive aspects of a lower profile in the turns while staying off of the bumpers and avoiding coil bind that can quickly change the spring rate of the suspension and take it to infinity.
I've talked with many hundreds of teams over the past five years about the evolution of the Big Bar and Soft Spring setups. What I've learned is that most, if not all, of the very successful teams have drawn back from extreme soft setups and very large sway bars for the most part. With rough and bumpy tracks, they unanimously stiffen up to keep the suspension free. Concord Motorsports Park is a track where the transitions are pronounced and can upset a car with a large sway bar.
The setup
I came up with was one where we used 500-600 pounds per inch (ppi) front springs, a 11/2 inch diameter sway bar, and a 250 ppi left rear spring and a 400 ppi right rear spring. RE Suspensions built us a set of hlins shocks that had a wide range of adjustment so that we could tune the transitions. The Panhard bar was set to complement the spring layout and weight distribution of this car using a computer software program designed to do just that.