As racecar drivers, a lot of us think we are irreplaceable behind the wheel of a car. Ask any veteran of the F1 grid and they will tell you, “We are all replaceable.” But when it comes to aligning your car, installing adjustable end links, or doing corner weights, drivers can easily be replaced with barbells you might find in your home gym. How and where you place those weights in the car can make a difference in your setup.
You may ask, is it really that important to put driver weight in a car when you are aligning it, or connecting a sway bar or during corner weighing? Great question. Here is some relevancy. If you have a racecar that weighs 2,000 pounds dry and you weigh 200 pounds as the driver, your body is 9 percent of the vehicle weight, which is a considerable amount. When corner-weighting a car — adjusting the perches on a coil-over shock to move the weight around the chassis — having 200 pounds in the driver seat makes a big difference. To test this theory, I aligned my car with a driver in the driver seat and set my camber. Then I had the driver get out and rechecked the camber with the car lighter. The camber did change. Why this matters is I don’t really care what the camber of the car is when nobody is in the driver seat, I only care about the setup of the car when it is going around the track. And it needs me in the driver seat to go around the track. At least in 2024, anyway.
The easiest thing to do is put on all of your safety equipment and sit in the car while somebody else fiddles with the alignment, corner weighting and sway bar end-link adjustments. This process takes a long time and eventually the driver will start to complain that he or she needs a bathroom break. Most situations we don’t have a crew of people to adjust our alignment for us. We are alone in the shop. So, to work by yourself and still adjust the car with the driver weight in the seat, you will need to replace yourself with some barbells and end plates. When I do this I try to replicate the weight as accurately as possible. The first thing to consider is what my weight is. It is not my weight when I step on the scale naked in the morning. The actual weight is what it is while wearing all of my safety gear. I put on all of the equipment and step on the scale. You will be surprised how much all that stuff weighs.
Once you have an accurate weight of the driver, then you need to start finding weights to shove in the driver’s compartment. I like to use weights I purchased from Walmart (because I have found they are the least expensive). I have multiple plates and barbells to try to accurately replicate how much I weigh. But shoving all of these weights into the driver seat really doesn’t replicate exactly where all of this weight is in the car. Some of this weight is at my feet near the pedals. When corner-weighting a car, the position of weight in a car makes all the difference. I wanted to know how much of my 181 pounds was in by butt when I am seated and how much is at my feet. It was a question I didn’t have the answer to, but needed to know to be more accurate.
The first step was to weigh myself on the scale, which was admittedly 181 pounds because I love cheeseburgers and ice cream. The next step was to find a box that replicated my driver’s seat height. I set that box on the scale and then weighed it. The box was so light it wouldn’t register on the scale making its weight negligible in the experiment.
The next step was to sit on the box with my feet out in front of me like I was sitting in a racecar. This would give me a weight on the scale, which would be lighter since not all of my weight was on my buttocks. Some of my weight was being held up by my feet, even in a seated position. Because the scale elevated my seat. I chose to put the RV leveling blocks under my feet so everything being weighed would be on the same level plane.
Once I had my butt weight recorded — it came in at a svelte 166 pounds — it was time to swap the scale to be under my feet and move the RV leveling blocks under my seat so things would again remain on the level plane. Based on the math, my feet should weigh the difference between my overall weight, 181 pounds, minus my seated weight, 166 pounds. When I sat on the box and then looked at the scale under my feet the experiment was working as it should, my feet registered 15 pounds. It turns out my physics teacher in college was right all along.
When you look at 15 pounds, you may say, “Who cares?” Well, 15 pounds is 8 percent of my body weight. We already discussed how much a driver’s weight makes a difference in the percentage of a car. And we know that weight position in a car makes a difference in how you set up your corner weights, ride height, camber adjustments and end-link lengths. So, it makes sense to me to replicate my driver weight and its distribution accurately when I am using barbells to replace myself in the car. Why do it wrong?
If I am going to take the extra time to make all of these minor adjustments to get my racecar dialed in perfectly, then I might as well try to be as accurate as possible when I am placing weight in the car to replicate my seated position as the driver. So, based on my little experiment, I placed 166 pounds in the driver’s seat, then I placed 15 pounds on the floorboard near the pedals and then I did all of my setup adjustments to get the car dialed to perfection.
All of this was done with nothing more than a bathroom scale, a few plastic blocks and some weights. Some may say I am overthinking this, but sitting around the shop at night tinkering on the car, I have nothing else to do except overthink this stuff. I’d rather spend time in the shop overthinking and over-preparing to try to avoid issues at the track. So, next time you are doing your setup, don’t forget to add driver weight to the car, and remember, not all of that weight goes into the seat.
Rob Krider is a four-time NASA Honda Challenge 4 National Champion, the author of the novel, “Cadet Blues,” and is the host of the “Stories and Cocktails” podcast.
