David J.

There is a difference for several reasons. As you know, sway bars are also referred to as anti-roll bars because they reduce chassis roll. This is done by resisting weight transfer to the outside tire by transferring some of that weight back to the inside tire. Because of this, it also keeps the chassis flatter through corners and tends to improve steering response. This doesn’t mean that weight transfer is bad. You need some level of weight transfer to the outside tire during cornering to maximize grip. However, too much is not good and can overload the suspension and tire causing loss of grip. I was going to type a really long explanation but it’s probably better to keep it simple.

Basically, you usually don’t want to control chassis roll with springs and oil only. Reason being is you can often compromise too much. The spring should only be stiff enough to support the weight of the chassis on that particular corner. This includes cornering force, acceleration force, braking force, bumps and every combination in between. Using a stiffer spring alone to reduce chassis roll can sometimes be too stiff over all making the car twitchy or chatter over bumps. It can also load the outside tires excessively with very little weight on the inside tires which can either cause loss of grip due to overheating or overloading of the tires or just accelerated wear on the tires. In that same situation, using softer springs and adding sway bars will transfer some of the cornering force to the inside tires sharing the load, making the chassis more efficient yet still handle the undulations of the track surface. A scenario where you might want to remove sway bars would be on low bite surfaces to maximize weight on the outside tire. It all depends on the conditions. Just keep in mind that sway bars are a tuning aid and knowing what they do will tell you when you need them.