What Is Steering Curve (Expo)?

Steering Curve (or Expo) changes the relationship between steering wheel movement on the transmitter and steering output at the servo.

In simple terms, it changes how sensitive the steering feels at different parts of wheel travel.

With Steering Curve, you can:
• Make steering smoother near center
• Increase or decrease steering aggressiveness
• Improve high-speed stability
• Make the car easier to drive consistently
• Fine-tune steering feel without changing endpoints

The “Expo” part stands for Exponential steering response. Instead of steering output increasing in a perfectly straight line, the radio changes the rate at which steering increases.

This means:
• Small steering wheel movements can produce less steering
• Large steering wheel movements can still achieve full steering lock
• Steering can feel softer or more aggressive depending on settings

Different radio manufacturers handle Expo values differently:
• Futaba typically uses negative Expo values to soften steering around center
• Spektrum and some others may use positive values for the same effect

Always verify how your specific radio handles Steering Curve (Expo).

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How Does Steering Curve Affect Your Car?

Steering Curve has a major impact on how the car feels to drive.

Even small changes can dramatically alter steering smoothness, corner entry feel and driver confidence.

More Steering Curve Softening
When Steering Curve is set to soften steering around center, the car will usually:
• Feel smoother at high speed
• Become easier to drive consistently
• Reduce twitchiness
• Be less reactive to small steering inputs
• Improve straight-line stability
• Feel calmer on rough tracks

Common Uses
• High-bite carpet racing
• Fast touring car tracks
• Loose dirt off-road tracks
• Beginners learning control
• Drag racing stability
• Crawlers needing precise steering

Potential Downsides
• Steering may feel lazy entering corners
• The car may respond slower in tight sections
• Quick direction changes can feel muted

Less Steering Curve Softening
Reducing Steering Curve softening makes steering more immediate and aggressive. The car will usually:
• React faster to steering input
• Feel more direct
• Turn harder initially
• Feel more responsive in tight corners
• Transition quicker side-to-side

Common Uses
• Technical tracks
• Tight indoor off-road layouts
• RC drifting
• Drivers wanting aggressive steering feel

Potential Downsides
• Can make the car nervous
• May cause overcorrection
• Harder to drive consistently
• Increased risk of traction rolling

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How Do You Change Steering Curve?

Steering Curve is adjusted through the transmitter menu system.

Most radios place it under:
• Steering Settings
• Steering Function
• EXP
• Exponential
• Curve
• Steering Curve

Basic Adjustment Process
Step 1: Open Steering Menu
Navigate to the steering function section of your radio.

Step 2: Locate Steering Curve (Expo)
Find the Expo or Steering Curve setting.

Step 3: Adjust the Value
Increase or decrease the Expo amount depending on desired feel.

Step 4: Test Drive the Car
Drive several laps and focus on:
• Corner entry
• Mid-corner stability
• Straight-line tracking
• Steering smoothness

Step 5: Fine-Tune Slowly
Adjust in small increments. A little Steering Curve change can make a huge difference.

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When To Change Steering Curve

You should consider adjusting Steering Curve when the steering feel does not match track conditions or driving style.

Increase Steering Curve Softening If:
• The car feels twitchy
• You are overcorrecting often
• The track has high grip
• The car traction rolls
• Straight-line driving feels unstable
• The steering feels too aggressive

Reduce Steering Curve Softening If:
• Steering feels numb
• Initial turn-in is weak
• The car reacts too slowly
• Tight corners require excessive wheel movement
• You want faster transitions

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What to Check After Changing Steering Curve

After adjusting Steering Curve, check the following areas to ensure the car still feels balanced.

Steering Dual Rate
Dual Rate changes total steering amount, while Steering Curve changes steering sensitivity. These settings work together.

Steering Endpoints (EPA)
Ensure the servo still reaches proper steering lock without binding.

Servo Speed
A very fast servo combined with aggressive Steering Curve can make the car difficult to control.

Gyro Settings
If using a gyro:
• Recheck gyro gain
• Verify steering corrections remain smooth
• Make sure the gyro is not overcompensating

Ackermann
Changing steering response can make Ackermann feel different during corner entry and mid-corner steering.

Toe Settings
Front Toe affects initial steering feel and works closely with Steering Curve.

Driver Consistency
Pay attention to:
• Lap consistency
• Steering smoothness
• Ease of correction

Often the best Steering Curve setting is the one that makes the car easier to drive consistently, not necessarily the most aggressive.

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Basic Steering Curve vs Advanced Settings

Basic Steering Curve
Basic Steering Curve (Expo) adjustments are designed to improve overall steering feel quickly.

Typical Basic Adjustments
• Small increases or decreases
• One global steering curve
• Simple smooth vs aggressive tuning
• Used by most drivers

Ideal For
• Beginners
• Club racers
• Bashers
• General driving

Advanced Steering Curve Settings
Advanced radios allow deeper customization of steering behavior.

Advanced Features May Include
• Multi-point steering curves
• Separate left/right steering curves
• Speed-sensitive steering response
• Steering linked to throttle position
• Different profiles for track conditions
• Model-specific steering maps

Advanced Uses
• Fine-tuning high-bite carpet cars
• Drift transition control
• Precision crawling setups
• Adapting steering feel to changing grip conditions

Advanced Steering Curve tuning is most beneficial for experienced drivers searching for maximum consistency and precision.

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FAQ

Q: What does Steering Curve (Expo) do in RC cars?
A: Steering Curve (Expo) changes steering sensitivity throughout wheel travel. It usually softens steering around center for smoother control.

Q: Is Steering Curve the same as Dual Rate?
A: No. Dual Rate changes total steering travel, while Steering Curve changes how steering responds during wheel movement.

Q: Does Steering Curve make the car slower?
A: Not directly. In many cases, proper Steering Curve improves consistency and lap times by making the car easier to drive.

Q: Should beginners use Steering Curve?
A: Yes. Mild Steering Curve can make a car easier to control and less twitchy.

Q: What is a good starting point for Steering Curve?
A: A mild softening setting is usually a safe starting point. Exact numbers vary by radio manufacturer.

Q: Why does my car feel twitchy at high speed?
A: The steering may be too aggressive near center. Increasing Steering Curve softening can help stabilize the car.

Q: Can Steering Curve help with drifting?
A: Yes. Drift drivers often fine-tune Steering Curve to balance smoothness and fast steering transitions.

Q: Should I adjust Steering Curve or Dual Rate first?
A: Typically:
1. Set steering endpoints (EPA)
2. Adjust Dual Rate
3. Fine-tune Steering Curve

This creates a more balanced setup.

Back to the RC Transmitter Settings Guide.