Virtual Dyno (power curves from drive logs)
Virtual Dyno turns a saved drive log into a dyno-style chart of horsepower and torque by rpm. Instead of your car's maximum performance, it shows the power you actually used on that drive. Free to use.
1.Overview
Virtual Dyno calculates power and torque at each rpm from the fuel flow and rpm in your drive log, and plots them. Any drive recorded with an OBD2 adapter can be viewed afterwards — nothing special to do while driving.
A chassis dyno runs the car flat out on rollers to measure the maximum power it can make. Virtual Dyno shows the power you actually used in everyday driving, so the same car can produce a different curve depending on how it was driven.
| Chassis dyno | Virtual Dyno | |
|---|---|---|
| Shows | The maximum power the car can make | The power you used on that drive |
| How | Full throttle on rollers | Analyzes an ordinary drive log afterwards |
| You need | A dyno facility | An OBD2 adapter and your phone |
| Values | Measured | Estimated from fuel flow (calibration improves accuracy) |
2.Opening it
On a record's detail screen, tap "Dyno" in the Route ⇄ Dyno toggle at the top left of the map block. The whole drive is analyzed the first time you open it, so long logs take a few seconds.
The Desktop app has the same toggle on its record detail screen (see §7).
3.Reading the chart
The white line is power (left axis, e.g. PS) and the green line is torque (right axis, e.g. kgf·m). Each peak is labeled with its value and rpm. Units follow the unit setting of the Estimated Power slot.
The curve connects the highest value seen at each rpm across the whole drive (the upper envelope). It doesn't look only for full-throttle pulls — every acceleration in the drive counts.
The horizontal axis only covers the rpm range reached on that drive; rpm you never reached is not drawn.
Example: mostly-highway drives show lower torque
On a mostly-highway drive in a kei van (catalog 64 PS / 9.7 kgf·m), the power peak came out at 64 ps @ 6600 rpm, matching the catalog, but the torque peak was 7.3 kgf·m @ 4000 rpm.
Flooring it to merge onto a highway sends the revs straight up, so the log is full of high-rpm, high-load data and has almost nothing from pressing hard at low rpm. Even an engine with strong low-end torque won't show it if you never used that range.
- To see low-end torque, use a drive that includes accelerating hard from around 2000–3000 rpm in a lower gear.
- Comparing drives on the same road driven the same way cancels out most of the estimation error, which makes differences in driving style — or before/after changes such as intake and exhaust mods — easy to compare.
- It also shows which rpm range you use day to day, which helps when thinking about gear choice or where you'd want more torque.
4.Switching between before and after calibration
From v1.3.9, drives with power calibration applied (see §6) show a "Before | After" toggle at the bottom left of the Dyno block. It opens on After.
Switching animates the curves and peak values. The vertical axis is fixed to the larger of the two, so you can see exactly how far calibration moved the curve.
Before shows values calculated with the standard coefficient (with the uncalibrated badge). It only changes the view — your calibration data stays as it is — and the screen opens on After again next time.
Drives without calibration don't show the toggle.
5.Sharing as an image
Tap the share button at the top right of the Virtual Dyno block to create a portrait image sized for social media (1080 × 1350 px, PNG), then send it to X, Instagram, LINE and so on from the share sheet, or save it to Photos. Free to use (v1.3.7 and later).
The image is designed to make sense on its own, so besides the chart it says which car and under what conditions. Text in the image is always in English so it reads the same wherever it ends up.
On drives with the Before | After toggle, the image follows whichever view you're looking at. Both images share the same axes, so posting them side by side shows the effect of calibration at a glance.
| What's in the image | Details |
|---|---|
| Vehicle | Maker, model and model code from your vehicle profile. Shows "--" if not entered |
| Engine | Displacement and fuel type at the time of recording (e.g. 660cc · Gasoline) |
| Peaks | Peak power and torque with the rpm they occurred at, in large type |
| Power curve | The Virtual Dyno chart |
| Drive | Date, driving time and distance |
| Calibration | The coefficient after calibration (e.g. "Calibrated ×0.84"), or an "Uncalibrated" badge and "Standard coefficient" before calibration or when not calibrated |
Place names, the route and the name of the drive log are never included, so the image does not reveal where you live. Enter the vehicle name (maker, model, model code, year) under "Vehicle info for power calibration" in your vehicle profile. Editing vehicle profiles is a Premium feature, so on the free plan the vehicle line shows "--".
6.Calibration (Premium)
Tap "Calibrate with this drive" at the bottom right of Virtual Dyno to re-measure the coefficient from that drive's acceleration data. Nothing to do while driving — record as usual and analyze afterwards.
Vehicle weight is required. Enter curb weight, occupants, cargo and transmission type (MT / AT / CVT) in the vehicle profile under "Vehicle info for power calibration".
The analysis compares the work the car actually did while accelerating (from speed change and mass) with the fuel it burned, and expresses the result as a ratio to the standard coefficient. You'll see something like "×0.84 / spread ±7% / normal acceleration, grade verified". Tap "Apply" and both the Estimated Power slot and Virtual Dyno switch to the calibrated value.
When accelerometer data is present, grades are detected and hill sections are excluded (from v1.3.4, G data is recorded automatically even without a G-meter slot). Older logs are treated as "grade unverified" and need more acceleration samples.
For best results, use a drive on flat roads that includes a few 40 → 80 km/h accelerations. Drives with only light acceleration tend to produce a lower coefficient.
Calibration is saved per vehicle profile. Use "Reset calibration" in the Estimated Power slot's detail settings to return to the standard coefficient.
Virtual Dyno and image sharing are free. Only calibration from real-world data is a Premium feature.
7.On Desktop
The Desktop app shows Virtual Dyno from the Route ⇄ Dyno toggle on the record detail screen. The coefficient you calibrated on your phone travels with the drive when you send it, and is shown as calibrated.
From Desktop v1.0.20, Virtual Dyno, estimated power and fuel economy values — and the distance and average speed of drive records — match the mobile app. Earlier versions could read a few percent high on some cars, such as those without a mass airflow (MAF) sensor. After updating to v1.0.20, saved drives are shown with the correct values automatically.
Calibration and the Before | After toggle are mobile-only.
8.FAQ
Torque reads lower than the catalog figure.
Virtual Dyno draws the power you used on that drive, so if you never pressed hard at low rpm, the torque peak comes out low. As in the example in §3, flooring it on the highway leaves almost no low-rpm data. Try a drive where you accelerate from 2000–3000 rpm in a lower gear.
It doesn't match the catalog horsepower.
The estimate is derived from fuel consumption, a different measurement from a catalog figure. After calibration, most cars land close to the catalog value.
Is it free?
Virtual Dyno and image sharing are free. Calibration from real-world data is a Premium feature.
Can I view older drive logs?
Yes. Drives recorded with v1.3.7 or later use the vehicle profile active at the time (fuel type and calibration); v1.3.6 and earlier use the profile currently selected. Logs recorded before v1.3.4 have no accelerometer data, so calibration treats them as "grade unverified".
The vehicle line in the shared image shows "--".
Enter maker, model and model code under "Vehicle info for power calibration" in your vehicle profile (Premium). Logs recorded with v1.3.6 or earlier, or whose profile has been deleted, show "--" so that a different car's name never appears.
Desktop and mobile show different values.
Update the Desktop app to v1.0.20 or later. Earlier versions used a different fuel-flow formula from the mobile app on some cars.
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