The range of adjustments on these vehicles is often very limited, but addressing just a few items can make a big difference in vehicle responsiveness, predictability, and performance.
Consider these basic adjustments to up the fun factor of an HPDE experience with a stock car
Alignment and negative camber
Stock performance cars almost always struggle with front end grip near the limit, and understeer can really sap the fun out of the track experience.
Adding negative camber on the front wheels in particular works to counteract the inherent understeer handling balance of most stock vehicles. Negative camber makes the car more responsive to steering inputs, and maximizes cornering traction as well.
Adjusting from just -1.1 to -1.9 at the front wheels resulted in a significant handling transformation for our Z/28.
"Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip when cornering. This is because it places the tire at a better angle to the road, transmitting the forces through the vertical plane of the tire rather than through a shear force across it."
Adjust and monitor tire pressures
Performance street tire advancement has corresponded to, and is arguably one step ahead of performance vehicle progress.
Current generation street performance tires like the Michelin Pilot Super Sport and Continental ExtremeContact Sport facilitate and enhance track day participation with stock vehicles. These tires have a wider operating range, and aren't nearly as finicky as many r-compound track tires. Nevertheless, tire pressures still have to be monitored and adjusted according to on track activity.
Dial your tire pressures down to begin the track day, and then make adjustments at the conclusion of each session. If you have a psi readout inside your vehicle, keep it up intra-session and glance at it occasionally if it's safe to do so. Note in what psi range the tires feel in their groove, and when they seem to be getting too hot (characterized by "greasy" handling). Adjust accordingly.
For more specific guidance, see How to set tire pressures for track days.
Whether it's your first time out on track or you're starting to get the hang of it, proper brake pads and fluid positively contribute to the HPDE experience.
We mentioned that stock performance cars often struggle with front end grip. Many steel brake systems also struggle with the heat generated by repeated hard braking out on track, and the responsiveness and behavior of the brake pedal/system can become inconsistent. Should this happen out on track you'll find yourself distracted and thinking about nothing else, for obvious reasons…
The way to avoid it is to upgrade brake pads and fluid. Racing brake fluid has a higher boiling point and other properties that keep it working as intended in a track environment. Similarly, track pads are specifically engineered to cope with the high heat and rigors of track use.
Check out Zeckhausen Racing for brake and fluid upgrade options by vehicle.