NFSU2 Savegame Editor

A browser-based career save editor for Need for Speed: Underground 2 (SPEED2.EXE saves, 54,966-byte 20CM files). Everything runs locally in the browser. Nothing is uploaded.

The live site is deployed to GitHub Pages from main. See doc.md for what we know about the save format.

Features

• Edit driver name and money, with checksums recalculated on download.
• View each car slot's make and model, read from the car type hash.
• Replace or add a car in a slot. Tuning is kept.
• Edit mapped performance parts and separate unique-performance flags.
• Dyno: simulate peak power and torque, 0–60, 0–100, quarter mile and top speed per setup (metric and imperial side by side), and auto-tune the ECU and turbo curves (needs your game's GLOBALB.BUN).
• Swap slots (experimental) and unlock all slots.

Development

Requirements: Node.js 24 or newer.

npm ci
npm run build    # compiles src/ to dist/ and copies static files
npm test         # build, then run the test suite
npm run clean    # remove dist/

Each build stamps the header with the package version and a UTC build number (YYYYMMDDhhmmss). The splash label lives in index.html; update it for the next feature milestone.

The source layout is:

• src/model/: save parsing and editing logic, with no DOM access.
• src/data/: static tables (performance parts, unlock ranges).
• src/controller/: the AngularJS controller, scope types, and file-input directive.
• src/main.ts: AngularJS bootstrap.
• src/test/: tests.

AngularJS 1.8.2 is loaded from a CDN in index.html.

Running locally

The editor fetches car-donors.json, so it must be served over HTTP rather than opened from disk. After npm run build, serve dist/:

cd dist
python -m http.server 8765

Then open http://127.0.0.1:8765/index.html.

Deployment

.github/workflows/deploy.yml runs the tests and builds on every push to main, then deploys dist/ to GitHub Pages. In the repository settings, set Pages > Build and deployment > Source to GitHub Actions once.

Usage

1. Choose a career save (for example treav0r). Files are read in the browser and never uploaded.

2. Edit the driver name and money, then click Apply profile.

3. Filled car slots show their make and model, identified by the car type hash at slot offset +0x014. Hashes absent from the donor list show as unknown; locked/open slots hide the car name.

4. Replace car (or Add car for an empty slot) writes a donor car's slot blocks. Tuning is kept.

5. Tune performance parts, install or stock a slot, or swap two slots.

6. Click Download edited save. Checksums are recalculated on download.

7. Choose a career save (for example treav0r). Files are read in the browser and never uploaded.

8. Edit the driver name and money, then click Apply profile.

9. Filled car slots show their make and model, identified by the car type hash at slot offset +0x014. Hashes absent from the donor list show as unknown; locked/open slots hide the car name.

10. Replace car (or Add car for an empty slot) writes a donor car's slot blocks. Tuning is kept.

11. Tune performance parts, install or stock a slot, or swap two slots.

12. Click Download edited save. Checksums are recalculated on download.

Notes

• car-donors.json is a copy of the donor table from GabriLex's nfsu2profilemaster. It contains each car's per-slot blocks, plus save-wide blocks that the editor ignores.
• Replace car writes only the slot's own blocks (+0x000, +0x0E0, +0x2B0). Save-wide blocks are not touched. Filling an empty slot copies the used-slot header from another slot, which is unverified. Test in game before relying on it.
• Variants with the same car type hash (base, sponsor and intro versions) show the first name listed. The separate +0x2BC model key is not used for names: different cars such as Sentra, Golf and Tiburon share it.
• Swap (experimental) copies a whole car slot block. It has not been tested in-game.
• Tuning shows performance part names and ordinary packages, without internal keys, offsets, prices or purchase-bit details. Inactive parts are disabled and visual-related flags are not shown. Technical mappings are recorded in technical.md.
• MAX OUT (in the tuning dialog header) enables the 54 active performance bytes, including mutually exclusive parts, and sets the nine unique flags; the game's own apply routine does not do this. It does not change the visual-related flags, purchase bookkeeping or inactive IDs. Only the muffler (15) and cold air intake (16) edits are confirmed by in-game save diffs.
• Unique controls edit separate per-car category flags without a confirmation prompt. They do not emulate the unique shop's event-status update or full reward process. See technical.md for the code trace and evidence limits.
• Unlock all sets the 420 bytes that NFSU2-ProfileCreator writes as 0xFF in each car slot (ranges in src/data/unlock-table.ts, offsets +0x462 to +0x7E1). It only writes those bytes. The byte-to-part mapping and the in-game effect are not verified yet.
• Dyno (in the tuning dialog) reads car data from GLOBAL\GLOBALB.BUN in your NFSU2 folder; the file is read locally and not shipped with the editor. A car needs a tunable ECU, turbo or transmission package installed. By default, Auto-tune ECU & turbo writes only the 18 curve bytes of the selected setup. Times come from the game's own dyno simulation and are not yet checked against the in-game screen. See technical.md.
• Optimize gearing & shift spacing is unchecked by default. Enable it to include unlocked final-drive and forward-gear settings in goal optimization. The search checks every shift, including gears outside the timed run, and balances the selected goal with average/worst-shift power-band coverage and more even percentage RPM drops. Both goal passes balance performance against shift quality using the same power-first reference. Excessive RPM drops are capped against the neutral transmission and its geometric spacing. This tunes ratios, not the game's shift-RPM thresholds. Apply saves those settings alongside the curves, leaving other setups and unrelated bytes unchanged. Locked and unused gears are preserved. Gearing is frozen during the horsepower passes. The game's adjacent-gear constraints and byte normalization are included; see technical.md.
• The three-step goal slider is Acceleration — Balanced — Top speed, defaulting to Balanced. Every setting considers 0–60, 0–100, quarter mile and top speed, with different priorities. Auto-tune first builds peak horsepower with ECU/turbo, runs two goal-specific passes over curves and optional gearing, then tries for more horsepower with gearing fixed. Final power changes are accepted only if no predicted acceleration time gets slower and neither top nor trap speed decreases relative to the goal-tuned result. All result figures remain visible; separate peak-power/torque goals are no longer needed.

Experimental traffic identities

The Replace car with dropdown includes a Traffic cars (experimental) group with 15 traffic vehicles, enabled only for filled, unlocked slots. This is an identity-only experiment, not a complete donor replacement: it changes only the car type hash, preserving existing body, parts and tuning. Appearance, player driving and career loading are unverified. Traffic replacement applies without confirmation. The game may fail to load the edited save; use a backup. Traffic slots are labeled experimental and DYNO is unavailable. Normal car replacement remains available to restore an ordinary car.

Tests

npm test

Fixture tests read testfile/treav0r and skip when that file is missing. testfile/ is gitignored. Dyno tests also need GLOBALB.BUN; they use the default install path or NFSU2_GLOBALB, and skip when it is missing.