Help with TrackDyno

Almost every bad number traces back to the vehicle profile. Check these first:

• Weight: the car with fuel, plus the driver and anything in it. Ten percent too heavy reads about ten percent too much power.
• Gearing: every gear ratio, the final drive and the tire's rolling radius. These turn speed into RPM, so a wrong final drive skews torque.
• Drag and frontal area: use your car's published Cd if you can find it.
• Drivetrain loss: this sets the gap between wheel and crank figures.

After you fix the profile, go to Settings → Recalculate saved runs to update your old runs with the new numbers.

Use a flat, straight, empty road where it's legal, or a closed course. Choose a gear that covers a wide RPM range (usually 3rd), roll at low RPM, then go to full throttle until near redline. Mount the phone firmly with a clear view of the sky. Two or three pulls in opposite directions average out wind and slope.

A phone reports its GPS position a fraction of a second after the moment it measured it. Most phones run about half a second behind. Left uncorrected, that delay makes acceleration look softer than it was. TrackDyno corrects for it automatically. With OBD-II connected it measures your phone's delay on every run and uses that typical figure for runs without OBD-II.

TrackDyno measures power at the wheels, which is what the road sees. Crank horsepower adds back the power lost in the transmission and driveline, using the drivetrain loss in your vehicle profile. Manufacturer ratings are crank figures.

No. TrackDyno works with just the phone. Without OBD-II, dyno pulls need a one-time microphone calibration so the app can follow your engine's RPM by sound. An adapter adds RPM and speed from the car itself, gear detection, auto-start at wide-open throttle and wheel-lockup checks when braking.

iPhone only connects to Bluetooth Low Energy (4.0+) or Wi-Fi OBD-II adapters. That's an Apple limit that applies to every app. Known to work: Vgate iCar Pro BLE and iCar 2S, vLinker MC+, OBDLink CX, Veepeak BLE+ and Panlong BLE.

Won't work: classic-Bluetooth ELM327 adapters, and adapters locked to their own apps, such as OBDeleven, Carly and BlueDriver.

1. Plug the adapter into the car's OBD-II port and turn the ignition on. The engine running is best.
2. In TrackDyno, open Settings → OBD-II (Bluetooth), turn on Use OBD-II adapter, tap Adapter → Scan and pick yours.
3. Check that the live RPM and speed move. The app remembers the adapter and reconnects next time.

That's normal. The standard throttle and pedal readings are raw sensor voltages, which never sweep the full range. TrackDyno uses the car's normalized pedal reading when it's available, and otherwise learns each car's real range automatically. You can check or reset it in Settings → Pedal calibration.

The gear ratio, final drive and tire size are what turn road speed into engine RPM. A wrong ratio gives a wrong RPM and a wrong torque figure, so the app asks for real values instead of guessing. Look in your owner's manual or the manufacturer's spec sheet, or search your model and transmission code. CVTs don't have fixed ratios, so they're exempt.

Go to Vehicle → your car → Calibrate microphone and hold the engine at idle, 2,000 rpm and 3,000 rpm when asked. TrackDyno learns which tone in your engine's sound tracks RPM. Sound is analyzed on the phone. Nothing is recorded or uploaded.

TrackDyno checks the vehicle profile before a run and lists anything missing. Tap Fix with setup assistant to fill it in. Dyno pulls without OBD-II also need the microphone calibration.

On your iPhone, and in your own private iCloud database if iCloud is on. That way they sync between your devices. We can't see them. Read the privacy policy for the details.

Yes. Open a run, tap Run data → Export data, and share the CSV files to Files, Numbers, Excel or anywhere else.