# SpinMetric: Air Turbo Balancer — Rotor Imbalance & Repair Log

> Rotor Imbalance & Repair Log (iPhone/iPad app by Elliot James.)

- Source: https://appshunter.io/ios/app/spinmetric-air-turbo-balancer/id6787040937 (this page in markdown: same URL + `.md`)
- Developer: [Elliot James](https://appshunter.io/developer/6787040939)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 15.6 · 1 MB
- Languages: American English
- Released: 2026-07-23
- Data updated: 2026-07-27
- User reviews in markdown: https://appshunter.io/ios/app/spinmetric-air-turbo-balancer/id6787040937/reviews.md

## What is SpinMetric?

Built for turbo rebuilders and balancing shops who get paid to be right.

WHAT IT DOES

BALANCING CARD JOURNAL
Every repair as a searchable card. Find any job by vehicle VIN or cartridge serial number, and see at a glance which units are in spec and which still have defects open.

POLAR IMBALANCE CHART
Map residual rotor imbalance as a precise polar vector — angle and amplitude on a 360° target. Drag to set the after-position or type exact values, and compare before/after on the same chart.

DRILLING CORRECTION CALCULATOR
Enter the measured imbalance, heavy angle, rotor radius and drill diameter, pick the material (steel, stainless, Inconel, titanium), and get the exact mass of metal to remove — in milligrams — plus the drill depth at the heavy spot.

CARTRIDGE PASSPORTS
A reference of common cartridges (Garrett, BorgWarner, Mitsubishi, Holset and more) with residual imbalance tolerance in mg·mm and rotor mass, so you always balance to the right limit.

DEFECT INSPECTION LOG
A wear checklist for every job: shaft play (radial and axial in mm), wheel geometry, wastegate condition. Nothing skipped, everything recorded.

VNT NOZZLE CALIBRATION
Set and calibrate the variable-geometry actuator against vacuum test points — the vacuum-to-travel curve, logged.

BEARING & REBUILD KIT REFERENCE
Cross-references and sizes for thrust bearings and spacer sleeves, so you order the right parts the first time.

BENCH TEST LOG
Record high-RPM cartridge tests with an oil-leak trace, so a unit only ships when it's proven.

TECHNICAL CONCLUSION EXPORT
Build a clean PDF report with before/after polar charts — the document that backs your warranty and keeps the customer confident.

BUILT FOR THE BENCH
- Switchable imbalance units (mg·mm, g·mm, mg·cm) and correction mass units (mg, g)
- Material density presets for accurate drilling math
- Works fully offline — your shop data stays on device

Stop balancing by feel. Measure it, correct it, prove it.


## Version history (last 1 release)

### 1.0 — 2026-07-23

No release notes.

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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 2026-07-27.*