# DynoGearRatio — Axle & DynoJet gear ratios

> Axle & DynoJet gear ratios (iPhone/iPad app by Skunk River Restorations, LLC.)

- Source: https://appshunter.io/ios/app/dynogearratio/id6787755963 (this page in markdown: same URL + `.md`)
- Developer: [Skunk River Restorations, LLC](https://appshunter.io/developer/1895639103)
- Category: Utilities
- Price: $0.99
- Age rating: 4+
- Requires: iOS 17.0 · 4 MB
- Languages: American English
- Released: 2026-08-20
- Data updated: 2026-08-28

## What is DynoGearRatio?

Find your car's rear axle (final drive) ratio with nothing but your phone, your tachometer, and a steady stretch of road. No OBD-II adapter, no jacking up the car, no counting ring-and-pinion teeth.

Enter your tire size, hold a steady speed with your tach on a round number, and tap Capture. The app reads your GPS speed at that instant and pairs it with your RPM and tire size to calculate the ratio. Take a few readings and it averages them — and shows the closest common production ratio as a sanity check.

HOW IT WORKS

Enter your tire: printed metric size (like 205/55R16), overall diameter, or a measured roll-out for the best accuracy
Pick a target RPM and hold your tach there in a steady gear
Tap Capture; the app grabs your GPS speed and computes the ratio
For the truest axle ratio, test in your direct 1:1 gear — or enter any gear's transmission ratio
DYNOJET MODE
Heading to the chassis dyno? Switch to DynoJet mode and it computes the exact "gear ratio" value to enter in DynoJet's Power Core software so the dyno can derive engine RPM from road speed. It's referenced to the DynoJet 224xLC's fixed 24-inch drum, so it needs no tire size or transmission ratio — just run the test in the gear you'll use for the pull.

FEATURES

Rear axle ratio from GPS speed + tach RPM + tire size — no hardware
DynoJet 224xLC gear-ratio setting for Power Core
Tire input by metric size, diameter, or measured roll-out
Average multiple readings; closest common ratio shown
MPH or KM/H
Works fully offline — no accounts, no ads, no tracking, no network access
Built for classic-car owners, restorers, and hot-rodders who need to know their gearing without pulling the diff cover.

Please don't operate the app while driving — have a passenger tap Capture, or use cruise control to hold a steady speed.

## Is DynoGearRatio safe?

Not enough ratings yet to assess DynoGearRatio.

## Is DynoGearRatio legit?

DynoGearRatio appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for DynoGearRatio is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0 — 2026-08-20

No release notes.

## More apps by Skunk River Restorations, LLC

- [LastDrive Garage](https://appshunter.io/ios/app/lastdrive-garage/id6764099935)
- [Fuel Pre-Pay Estimator](https://appshunter.io/ios/app/fuel-pre-pay-estimator/id6769810021)
- [TachoSpeed](https://appshunter.io/ios/app/tachospeed/id6771848185)
- [RaceCarLogBook](https://appshunter.io/ios/app/racecarlogbook/id6773467838)
- [SUTuner](https://appshunter.io/ios/app/sutuner/id6801878820)

All apps by Skunk River Restorations, LLC: https://appshunter.io/developer/1895639103

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-28.*