Set the fastest corners on the track first, then trim front and rear downforce together in small, equal steps to cut drag without upsetting the balance you just found. Aero grip only matters at speed, so it needs its own process, separate from the mechanical setup underneath it.
Why aero is different from mechanical grip
Mechanical grip is always present. Aerodynamic grip grows with speed, pressing the tires into the track harder the faster you go. That’s a real advantage in medium- and high-speed corners, but it comes at a cost: more downforce means more drag, which costs straight-line speed. A setup that feels balanced in slow corners can behave completely differently once you’re fast enough to load the wings.
How to set it up, in order
- Get the mechanical setup right first. Springs, anti-roll bars, and weight distribution should already make the car predictable through all three phases before you touch aero. Aero is a refinement layer, not a fix for a car that isn’t balanced yet.
- Find your fastest corner or sequence. This is where aero forces matter most. Set front-to-rear balance so the car is stable and predictable there before anything else.
- Balance front and rear downforce. More front downforce sharpens turn-in at speed but can leave the rear relatively loose, high-speed oversteer. More rear downforce stabilizes the rear but can make the car reluctant to rotate in fast sections if you overdo it.
- Trim for drag once the balance holds. Reduce front and rear downforce by small, equal amounts and check lap time. If it drops or the car gets unstable, go back to the last setting that worked.
Watch ride height and springs too
More downforce pushes the car closer to the track, which changes how the suspension behaves under load. If the car bottoms out, you lose both mechanical grip and aero efficiency at once. Ride height and spring support have to be stiff enough to hold the platform once real aero load shows up.
The bigger picture
More downforce isn’t automatically better. The right amount is just enough to get through the fastest corners with confidence, without dragging unnecessary downforce through the rest of the lap. Get mechanical balance right first, then use aero to refine what’s already working.
This is the same phase-and-balance approach built into onRails: get the fundamentals right before refining. See Build Your Own Setup for the full build order.
Related questions
Should I set up aero before or after mechanical grip?
After. Aero adjustments refine a setup that’s already predictable through corners at low speed. Trying to fix a fundamentally unbalanced car with wings just hides the problem at high speed and leaves it untouched everywhere else.
Does more downforce always mean better lap times?
No. Extra downforce past what the fastest corners actually need just adds drag you’re carrying the rest of the lap for no benefit.
Why does my car feel fine in slow corners but unstable in fast ones?
That’s a sign of an aero balance issue rather than a mechanical one, since aero forces only become significant at speed. Check front-to-rear downforce balance before touching springs or anti-roll bars.