Microdyno measures horsepower and torque of your Vespa from one full-throttle pull in third gear. With the phone's microphone, or with the MicroDyno sensor wired straight to the ignition, optionally with lambda and AFR from a wideband probe.
Works without an account, no ads. Optional cloud sync and browser access at app.microdyno.de.
For the power curve the app needs just one thing: how fast the rpm climbs at full throttle. From that, the weight and the gearing it computes power and torque. It can get the rpm in two ways.
| By microphoneNo hardware | Straight from the ignitionWith MicroDyno sensor | |
|---|---|---|
| How it works | The phone rides in a backpack and records the engine. The app finds the firing frequency in the engine noise and turns it into rpm. | The sensor hangs on the ignition with two wires and sends every pulse over Bluetooth to the app. The rpm is live on the phone and on the Apple Watch. |
| You need | Only the app and a backpack | MicroDyno-RPM or MicroDyno-Lambda-RPM |
| After the run | Trim the recording, check the harmonics with a couple of taps | Nothing. The result is there immediately. |
| Lambda and AFR | No | Yes, with the MicroDyno-Lambda-RPM, live and in the curve |
| Good for | Quick comparisons, any engine | Tuning work, lambda measurement |
Three tabs: Recordings, Results, Settings. Everything else happens in the background.
From the rpm trace, the weight and the gearing. Aerodynamic drag, rolling resistance and rotating masses are included, and the weather is corrected to DIN 70020.
A wizard walks you through frame, primary drive, gearbox and tyre. Keep several vehicles and change the gear even after the measurement.
For microphone recordings you see the spectrogram and tap the correct firing frequency. Anything that is not the engine, you simply wipe away.
Every run stays saved. Stack several curves on top of each other and see at once what the last change did. If you want, the app syncs everything to the cloud, and you edit vehicles and runs on a PC in the browser at app.microdyno.de.
With the MicroDyno-Lambda-RPM you see the air-fuel ratio live and as an overlay on the power curve. Ideal for jetting.
The watch shows AFR straight from the sensor, on your wrist. If the mixture drifts from the optimum at full throttle you see it at once: a badly set carburettor, an air leak or a blockage shows up before the engine takes damage.
Same Vespa, same weekend: once on a roller dyno, three times on the road with the MicroDyno-RPM sensor. With the right weight and gearing entered, the road runs land within a few percent of the dyno sheet.
Between 4,000 and 8,500 rpm the ratio of app to dyno averages 1.03. The dyno sheet itself is interpolated from three similar runs. Comparisons with more dynos will follow.
Two small Bluetooth boxes. Both pick the rpm straight off the ignition, one also measures lambda and AFR with a Bosch LSU 4.9 wideband probe.
Two wires to the AC output of the ignition, done. Runs on a battery, goes to sleep after five minutes without the engine running and wakes up on the first ignition pulse.
Rpm like the RPM sensor, plus a Bosch LSU 4.9 wideband probe in the exhaust. Runs off a 12 V battery, heats the probe only once the engine runs, and switches it off five minutes after shutdown.
The sensors are not available to order yet. Shop status
From the first vehicle in the app to the measurement run to wiring the sensors. With wiring diagrams for both boxes and an explanation of when the lambda probe heats.
Enter weight and gearing in the app, then accelerate at full throttle in third gear from low rpm to the maximum. From the rpm rise Microdyno computes horsepower and torque over rpm, just like a roller dyno does from the acceleration of its drum. The rpm comes from the phone microphone or from the MicroDyno sensor on the ignition.
A Bosch LSU 4.9 wideband probe. It needs an M18×1.5 weld-in boss in the exhaust, as close to the cylinder as possible. The MicroDyno-Lambda-RPM heats and reads the probe and shows AFR and lambda live in the app and on the Apple Watch.
A two-stroke at full throttle usually runs around AFR 12 to 13, clearly richer than lambda 1 (AFR 14.7). Leaner than that it runs hot and risks a seizure. With the lambda readout you jet the carburettor per throttle position: idle, part throttle and full throttle separately.
Accurate enough to see changes. On our test Vespa three road runs landed within a few percent of a roller dyno. What matters is the correct total weight including the rider and the correct gearing. If either is wrong, the whole curve shifts.
In third gear the pull lasts long enough to get a clean curve without going too fast. You can use another gear as long as you enter it in the app.
No. The gearbox wizard knows many Vespa combinations, but you can enter any gearing and any tyre. The sensor works with any ignition that has an AC output. You set the pulses per revolution in the app.
The microphone only for measuring without a sensor. Location is optional: the app uses it to fetch temperature, pressure and humidity for the weather correction and to show GPS speed during sensor runs. Everything works without it, you just enter the weather yourself.
It stays on your phone. The app works without an account and shows no ads. If you want, switch on cloud sync: your vehicles, recordings and results are then on all your devices, and you can edit everything on a PC in the browser at app.microdyno.de. Without the cloud, the app only contacts the internet for weather data and to check for new sensor firmware.
No. The sensor accepts one Bluetooth connection. While the watch is connected the phone cannot get in, and the other way round.
For iPhone and Android. With cloud sync also in the browser at app.microdyno.de.