SUTuner
SU Needle Finder & Tuner
$9.99 · Designed for iPad. Not verified for macOS.
Find, tune & compare SU carburetor needles: all 3 jet sizes, dyno AFR import, and a 89-vehicle factory needle reference.
SUTuner replaces the old SU needle spreadsheet with a modern needle-matching and tuning tool for SU carburetors — covering all three jet families (0.090", 0.100", and 0.125") across 683 real needles.
FIND
Enter the diameters you want at any of 16 stations and SUTuner ranks the closest-matching needles by total deviation or least-squares fit — exactly like the classic spreadsheet, but built for your phone.
TUNE
Start from a needle you already have, pick a region — Idle, Low Cruise, Mid Cruise/Low Accel, Hi Cruise, Hi Accel, or the whole needle — and search Richer or Leaner. SUTuner finds real needles that shift just that region, ranked by the smallest change everywhere else.
COMPARE
Overlay up to 4 needles at once on diameter and flow-area charts, normalized at idle so shapes are directly comparable, or switch to raw diameters to see real idle differences.
APPLICATIONS
A built-in reference of 89 factory vehicle applications across Jaguar, MG, Austin-Healey, Mini, and Triumph — standard, rich, and lean needle codes, spring type, and a direct link to each needle's own data.
DYNO AFR LOG
Tuning on a dyno? Import your logged AFR (CSV, with vacuum, MAP, or PSI) and SUTuner plots it against the needle's own station chart with editable target bands, so you can see exactly which region is running rich or lean. Keep a separate log per needle you test and compare them side by side.
SUTuner works fully offline. No accounts, no ads, no tracking, no network access of any kind — everything stays on your device.
Ratings & Reviews
The developer, Skunk River Restorations, LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Skunk River Restorations, LLC
- Size
- 5 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Skunk River Restorations, LLC
