Troubleshooting

Garage Adjustments

Instability, looseness, or tendency to spin:

Except for the left-rear, ride heights are generally too low.
Left-rear ride height is too high.
Cross-weight (wedge) is too low (see “cross-weight…is too low”, below).
Track bar is too high.
Truck arms are too high.
Ballast is too far back.
Front spring rates are too soft.
Rear spring rates are too stiff.
Front tire pressures are excessively high.
Rear tire pressures are excessively low.

Excessive stability, tightness, or resistance to turning:

Cross-weight (wedge) is too high (see “cross-weight…is too high”, below).
Except for the left-rear, ride heights are generally too high.
Track bar is too low.
Truck arms are too low.
Ballast is too far forward.
Front spring rates are too stiff.
Rear spring rates are too soft.
Front tire pressures are excessively low.
Rear tire pressures are excessively high.

Loose (oversteer) on both turn entry (braking) and exit (acceleration):

Left-rear ride height is too high.
Cross-weight (wedge) is too low (see “cross-weight…is too low”, below).
Left-front spring rate too high (stiffer).
Front spring rates too low.
Rear spring rates too high.
Left-front tire pressure too high.

Tight (understeer) on both entry (braking) and exit (acceleration):

Left-front spring rate too low (softer).
Cross-weight (wedge) is too high (see “cross-weight…is too high”, below).
Front spring rates too high.
Rear spring rates too low.

Tight (understeer) on entry (braking), loose (oversteer) on exit (acceleration):

Insufficient front spring stagger (stiffer left and/or softer right-front springs).
Excessive rear spring stagger (softer left and/or stiffer right-rear springs).
Excessive track bar stagger (mounted too low on the left, and/or too high on the right).

Loose (oversteer) on entry (braking), tight (understeer) on exit (acceleration):

Excessive front spring stagger (softer left and/or stiffer right-front springs).
Insufficient rear spring stagger (stiffer left and/or softer right-rear springs).
Insufficient track bar stagger (mounted too high on the left, and/or too low on the right).

Car wants to spin (oversteer) under throttle lift and/or hard braking (turn entry):

Excessive front spring stagger (softer left and/or stiffer right-front springs).
Insufficient rear spring stagger (stiffer left and/or softer right-rear springs).
Insufficient front shock bump (compression) stiffness (too soft).
Excessive rear shock rebound stiffness (too stiff).

Car wants to plow (understeer) under throttle lift and/or hard braking (turn entry):

Insufficient front spring stagger (stiffer left and/or softer right-front springs).
Excessive rear spring stagger (softer left and/or stiffer right-rear springs).
Excessive front shock bump (compression) stiffness (too stiff).
Insufficient rear shock rebound stiffness (too soft).

Car wants to spin (oversteer) under hard acceleration (turn exit):

Insufficient front spring stagger (stiffer left and/or softer right-front springs).
Excessive rear spring stagger (softer left and/or stiffer right-rear springs).
Excessive rear shock bump (compression) stiffness (too stiff).
Insufficient front shock rebound stiffness (too soft).

Car wants to plow (understeer) under hard acceleration (turn exit):

Excessive front spring stagger (softer left and/or stiffer right-rear springs).
Insufficient rear spring stagger (stiffer left and/or softer right-front springs).
Insufficient rear shock bump (compression) stiffness (too soft).
Excessive front shock rebound stiffness (too stiff).

Car wants to spin (oversteer) when coasting through a turn:

Right-front spring rate too soft (roll couple distribution).
Right-rear spring rate too stiff (roll couple distribution).
Right-front tire pressure too low.

Car wants to plow (understeer) when coasting through a turn:

Right-front spring rate too stiff (excessive cross-weight; see “cross-weight…is too high”, below).
Left-rear spring rate too stiff (excessive cross-weight; see “cross-weight…is too high”, below).
Right-rear spring rate too soft (roll couple distribution).

Snap loose (oversteer/spin) condition, especially when low on fuel:

Excessive rear spring stagger (softer left and/or stiffer right-rear springs).
Ballast too far back.
Excessive front anti-roll bar link slack/insufficient front anti-roll bar preload.

Car becomes tight (understeer) during a long run:

Ballast too far forward.
Track bar too low.
Right-front tire overworked (excessive negative camber, excessive wedge/cross-weight).

Car becomes loose (oversteer) during a long run:

Ballast too far rearward.
Track bar too high.
Right-rear tire overworked (insufficient negative camber, insufficient wedge/cross-weight).

Cross-weight (wedge) is too low:

Right-front and/or left-rear ride height is too low.
Left-front and/or right-rear ride height is too high.
Right-front and/or left-rear tire pressure is too low.
Left-front and/or right-rear tire pressure is too high.

Cross-weight (wedge) is too high:

Right-front and/or left-rear ride height is too high.
Left-front and/or right-rear ride height is too low.
Right-front and/or left-rear tire pressure is too high.
Left-front and/or right-rear tire pressure is too low.

Race Adjustments

Note that race adjustments to the left-rear generally affect turn entry; while the right-rear generally affects turn exit.

Note that these adjustments may have variable and sometimes unpredictable effects. For example, reducing tire pressure up front will lower the front ride height, and it may be enough to cause ride height problems make the splitter hit the ground. The best way to find out what your setup will do is to run a few laps, pit, and make adjustments. You can then re-test in simulated pit stop conditions to see how the different changes alter your car’s behavior and controllability.

Also, you shouldn’t make all of the listed adjustments; but should pick a change or combination of changes that makes the most sense for what you’re trying to achieve.

Read carefully: Tire pressure changes have the opposite effect on entry versus exit; e.g., if you make a pressure change to tighten the chassis, it will tighten the exit but loosen the entry!

Car is too loose:

Brake bias is too far back (increase the value to remedy)
Raise the left-rear ride height (use negative/decreased spring perch offset; left-pointing arrow).
Lower the right-rear ride height (use positive/increased spring perch offset; right-pointing arrow).
Add tire pressure at the left-rear (loosens entry, tightens exit).
Add tire pressure at the right-front (loosens entry, tightens exit).
Reduce tire pressure at the right-rear (loosens entry, tightens exit, center-off).
Reduce tire pressure at the left-front (loosens entry, tightens exit).

Car is too tight:

Brake bias is too far forward (decrease the value to remedy)
Lower the left-rear ride height (use positive/increased spring perch offset; right-pointing arrow).
Raise the right-rear ride height (use negative/decreased spring perch offset; left-pointing arrow).
Add tire pressure at the right-rear (tightens entry, loosens exit, center off).
Add tire pressure at the left-front (tightens entry, loosens exit).
Reduce tire pressure at the left-rear (tightens entry, loosens exit).
Reduce tire pressure at the right-front (tightens entry, loosens exit).