Congratulations! You’ve just been promoted to manager. In this case, if you’re driving a race car or road car, you’re now a weight manager. Every single road car and race car have one thing in common – tire contact patches. Cars can sit still, accelerate, corner and brake. Sometimes there will be multiple combinations of the above. The only thing connecting that car to the track are the four little rubber tire contact patches about the size of your hand. 

Some vehicles are designed to have a “perfect” 50/50 weight distribution at rest. Other cars are designed to have more weight on the front and others more weight on the rear. No matter which set-up belongs to your car, all of those weights will vary when the vehicle is in motion. The laws of physics apply to all equally. If you accelerate, you’ll transfer weight to the rear. If you decelerate, you’ll transfer weight to the front. Of course cornering will transfer weight side-to-side. The bottom line with all of this weight transfer is that the tire contact patch will vary depending upon the vehicle dynamics. 

As a driver, it’s up to you to understand and compensate via throttle, brake and steering inputs to maximize how transferring weight affects the contact patch. The more you understand what’s happening beneath you, the better equipped you are to look forward down the track and cut your lap times down. In a road car situation, for example driving a VIP in a limousine, it’s critical to make the weight transfer as smooth as possible. You don’t want your client getting car sick due to unexpected and rough driving.

Picture a bathtub full of water. Your goal is to drive that bathtub without spilling any water. This technique takes lots of practice. Throttle and brakes are not on/off switches if you’re trying to be smooth. Yanking on the steering wheel suddenly will not allow the car to “take a set” before you complete the movement. When this happens, the tires are overloaded and can’t react quick enough to provide you with the grip you want.

ABS and vehicle stability programs are in place because the driver has “overdriven” the amount of grip the tires can provide. Often times it’s because the driver wasn’t smooth and deliberate in managing the weight on the tires. Threshold braking will typically stop a vehicle quicker than ABS. The reason being is that the driver is using the tire contact patches to their maximum capability. As soon as you go past the threshold you’ve now overloaded the contact patches.

So the next time you’re on the street or track, work on being smooth and managing the weight over your tires. Your VIP or stopwatch will thank you for it!

 


By Larry Mason

Copyright © 2021 Larry Mason