CarX Street Build Optimizer computes a complete setup for YOUR car in CarX Street: gear ratios, differential, suspension, dampers, anti-roll bars, alignment and brakes. You enter your car's data (including a screenshot of its dyno), the tool outputs values ready to copy as-is into the game's tuning menu.

Without a tool, tuning a gearbox after an engine swap means an hour of trial and error. Here, analyzing your torque curve places every shift inside the engine's powerband, and the whole chassis is computed consistently, in 2 minutes.

Philosophy: the tool doesn't replace your driving. It gives you a mathematically balanced baseline that's already ~90% right. The last few % (your style, your spot) are yours to fine-tune in game, and you can edit your build anytime.

A build is created with the 5-step form. Every step has a « ? » help bubble on each field, plus a 'Where to find these values in game?' block with actual game screenshots.

1. 1 Identity : build name, car, discipline (see below) and drivetrain.
2. 2 Engine & Dyno : rev limiter, power, torque stats, turbo pressure, then upload the dyno screenshot. This is the key step, the analysis is mandatory.
3. 3 Transmission : stock gearbox (final drive, last gear), corner exit speed and target top speed of your discipline.
4. 4 Chassis : weight, balance, wheelbase, track widths, center of mass height. Wheelbase and tracks are found on the internet (real model's spec sheet).
5. 5 Tires : front/rear size and grip, read directly from the tires in game (e.g. 285/30 R17).

At the end, the build is saved and you land straight on the results page. Limit: 10 builds per account.

"My Builds" (/builds) is your garage: every setup you've saved, at a glance.

• Search bar: live filter by build or car name.
• Discipline chips (Grip, Track, Drift, Touge, Gymkhana, Drag) to show only one style at a time.
• Sort by creation date, name, power or weight.
• Each card lets you view the full tuning or edit the build directly.

Limit: 10 builds per account. Delete or edit an old build instead of creating a new one.

Every change to a build is saved automatically. Nothing is ever lost.

• "History" button on a build's page: every past version, most recent first.
• Compare any two versions: a table shows only the fields that changed, before → after.
• Handy after a big tuning session to pinpoint exactly what made the difference.

A profile page (your avatar, top of the sidebar) tracks your progress as a tuner.

• A rank that climbs with your real activity (builds created, versions iterated, dyno analyses, builds shared, feedback sent), from Garage Rookie to Circuit Legend.
• 9 badges to unlock: first build, 5 versions on one build, Vmax within 1 km/h, 10 dyno analyses, a build cloned by another player, 100 views on a public build, a feedback that got a reply, 4 different disciplines, 30 days as a member.
• A popup lets you know the moment you unlock a badge.

Any build can be made public ("Share" button on its page): it becomes visible on a dedicated page and in the "Community" gallery (/community).

• The gallery can be filtered by discipline, power class (C1 to CS+), car or author, and sorted by date or popularity.
• Sharing lets you declare the parts actually installed in-game (parts sheet), shown on your build's public page.
• "Use as a base" button on another player's public build: clones it directly into your garage to adapt to your car.
• The parts sheet now offers any engine or gearbox in the game, not only the swaps the game lists for your car. This matches what's actually possible in-game.

The dyno analysis reads your screenshot with computer vision: it isolates the blue curve (torque) and the white one (power), detects the orange cursor (rev limiter) and derives peaks and powerband. For a reliable read:

• PC/console: capture the WHOLE dyno screen, with the orange cursor visible. Mobile: crop to keep ONLY the chart (no stat panels around it).
• Required: a real screenshot, sharp, NEVER a photo taken with a phone or another device. The analysis won't work otherwise.
• Both curves must be readable (blue = torque Nm, white = power).
• After the analysis, check the displayed peaks match the chart before moving on.

Turbo engine? Enter the boost (bar) in the engine step: in-game torque stats EXCLUDE boost, the tool corrects automatically (e.g. 197 Nm shown @ 0.6 bar ≈ 300 Nm real).

The discipline is the #1 input of the whole calculation: it sets the gearbox's useful speed range and every chassis preset. Pick the one matching YOUR usage:

No value is an arbitrary lookup table: every module is a physical model, calibrated on setups validated in game.

A build page shows the 4 COPY-ME sections first, in the game's tuning menu order: Transmission, Differential, Suspension, Alignment & brakes. Copy the values as-is, section by section.

• The gradient bars visualize gearbox spacing and locks. No need to interpret them, only the values matter.
• 'Calculation details & input data' (collapsed): theoretical top speed, drop rpm, powerband, top speed per gear and everything you entered.
• 'Dyno charts' (collapsed): your extracted curve + wheel torque per gear, with the powerband highlighted.

An orange ⚠ at the top flags a compromise (e.g. speed range too wide for the gear count): read it, it tells you what to change.

• ⚠ Units are in parentheses on every field: tracks and wheelbase in METERS (1.48, not 1480), weight in kg, center of mass in INCHES.
• ⚠ Turbo: don't correct torque yourself. Enter the game stats as-is plus the boost pressure, the tool does the conversion.
• ⚠ A blurry or cropped dyno screenshot = cascading wrong values (powerband → gearbox → diff). Always check the displayed peaks after the analysis.
• ⚠ After changing engine, turbo or tires, redo the dyno analysis and update the build. Setups are only valid for the data entered.
• ⚠ The tool is an early version. If a value feels off in game, send a feedback (bubble button bottom right) with the build name. The team can now reply directly, and you'll be notified by email and in the app.
• ⚠ Aero (not covered by the calculator yet): max out front downforce, run rear equal or one notch above front. Too much REAR downforce eats acceleration. It's a common, high-impact setting many players undertune.
• ⚠ Slow vs Fast dampers: SLOW governs chassis behavior under steering/braking/throttle (overall handling and balance), so tune it first. FAST governs wheel movement over curbs and bumps (grip and stability on rough surfaces). Soften it if the car unsettles on bumpy roads (touge) even if slow feels right.