Mini-Z Gyro Installation and Setup Guide

At 1/28 scale, rear-wheel-drive cars are fast and snappy — sometimes too snappy. Snap oversteer happens in milliseconds, faster than any driver can react. A gyro corrects it automatically, counter-steering to stabilize the rear before you’ve registered the slide.

This guide covers installation and setup for the Kyosho MZW405 and the DasMikro drop-in replacement. Both mount identically.

What a Gyro Does

The gyro measures yaw rotation and applies counter-steer through the servo when the car starts to rotate faster than commanded. It doesn’t drive the car — it catches it when the rear steps out.

The amount of correction is controlled by gain. Too little gain and the gyro does nothing useful. Too much and the steering will oscillate or fight itself — called “hunting.” The goal is the highest gain where the car still drives cleanly.

What You’ll Need

• MZW405 gyro unit (Kyosho OEM) or DasMikro equivalent
• 1.5mm hex driver
• Small Phillips screwdriver

Installation

Step 1 — Remove the body and clear the chassis. Take off the body clips and body. The gyro mounts to the top of the main chassis board, typically above the front axle area.

Step 2 — Mount the gyro. Peel the adhesive backing and press the gyro firmly to the mounting location. On the MR-03 EVO, the correct position is slightly forward of center on the chassis board. The gyro must sit flat — do not mount over raised components or wiring.

Apply firm pressure for 30 seconds. The bond strengthens over the first hour of use.

Step 3 — Connect the gyro lead. Plug the gyro connector into the designated port on the ESC/receiver board. On the MR-03 EVO board, this is labeled GY or GYRO. One connector, one direction — it won’t fit backwards.

Step 4 — Verify direction setting. This is the step most people get wrong. The gyro has a direction switch (physical or software-based depending on model). If direction is reversed, the gyro will amplify slides instead of correcting them.

To check: with the car sitting still, push the rear of the car to the left. The front wheels should steer slightly left (counter-steer). If they turn right, reverse the direction setting.

Do this check every time you install or swap a gyro. It takes ten seconds and prevents a lot of confused laps.

Gain Tuning

Start with gain at 50% of the adjustment range. Drive several laps and observe:

Gain too low — The rear steps out unpredictably on corner exit. The gyro doesn’t seem to be doing much.

Gain too high — The steering oscillates or wiggles on straights. The car feels nervous even when going in a straight line.

Increase gain in small increments until you first notice hunting, then back off two steps. That’s your working range. Most MR-03 and MR-04 setups run well between 40–70% depending on surface grip.

Surface and Setup Interactions

• Higher gain works better on lower-grip surfaces. The gyro needs to work harder when tires have less natural bite.
• On high-grip RCP, lower gain is often cleaner. The tires provide natural stability and you want the gyro to assist, not dominate.
• Re-tune after tire compound changes. Different compounds change the grip baseline, which changes your optimal gain.

Common Mistakes

Mounting over a bump or wire. The gyro must sit flat. Any flex in the mounting surface causes false readings and erratic behavior.

Wrong direction. Test the direction on every gyro install. It’s fast and the consequence of skipping it is the car actively fighting you.

Blaming the gyro for setup problems. If the car still snaps out despite maximum gain, the root cause is likely tire compound, T-plate stiffness, or rear weight distribution — not the gyro. A gyro can help manage oversteer; it can’t fix a fundamentally unbalanced setup.