Turn your red
deltas purple.
Pick a car, a track and a PP limit. Purple Delta returns a complete, physics-calibrated setup in milliseconds — then tells you exactly what to change when the car won't behave.
579 cars/122 layouts/every PP & weather
Unofficial companion for Gran Turismo 7 — not made by or affiliated with Sony or Polyphony Digital.
Setups for cars from manufacturers across the game
In-game vehicle names, used for identification only — not affiliated with any manufacturer.
From guesswork to a purple lap.
- 01
You're tuning by feel
Sliders everywhere, forum guesswork, and a car that snaps mid-corner. The clock stays red.
- 02
The engine does the physics
Weight transfer, slip angles and yaw response — solved for your exact car, track and PP in milliseconds.
- 03
The delta goes purple
A complete, balanced setup lands on your screen. Copy it in, and the lap finally turns purple.
Scroll to watch the engine close the gap.
One app for the whole tuning loop.
Diagnose the car, generate the numbers, store every build, and share the fast ones with the grid.
Tell it how the car misbehaves. Get the precise values back.
Snap-oversteer on lift? Mid-corner understeer? Pick the symptom and Purple Delta returns the precise suspension, differential and downforce changes — aware of the parts you've actually fitted.
● Snap oversteer on lift
LSD decel −6 · Rear toe +0.10
● Understeer mid-corner
Front anti-roll bar −2 · Front camber +0.3°
● Won't rotate on entry
Brake balance +2 · Rear spring −0.4
● Unstable under braking
Rear ride −3 · Damper comp +1
Four build modes per car
Stock, Max Performance, BOP Restricted and fully Custom — saved and one tap away, for every car you own.
Saved builds
Unlimited
Free & Pro
Share the fast ones
Publish a build, browse what the grid is running, like and comment.
This week's Daily Races
Free picks and ready setups for the current Sport mode rotation, refreshed weekly.
Describe the problem.
Get the exact fix.
Validated against a 10×10 physics matrix and gated on your car's drivetrain, fitted parts and BOP state — so it never tells you to change a part you don't have.
› symptom snap oversteer on lift
› context RWD · 480 PP
› prescribing…
note · rear anti-roll bar left soft — chassis is already on the limit
Real vehicle dynamics,
solved on your phone.
Purple Delta isn't a lookup table of forum tunes. It's a physics engine that reasons about your exact car the way a race engineer would.
Weight transfer
Every braking, cornering and throttle input shifts load between the four contact patches. The engine models that transfer to set spring, damper and anti-roll balance for grip where you need it.
Slip angles
A tyre makes peak grip in a narrow slip-angle window. Camber, toe and pressure targets are tuned to keep all four tyres inside that window through the corner — not just on the straight.
Yaw response
How fast the car rotates about its vertical axis decides whether it feels nervous or planted. Differential, rear toe and downforce are balanced to give a stable, predictable yaw rate on and off throttle.
PP & BOP solver
Power restrictor and ballast are solved together — with a downforce-aware verification pass — to land exactly on your Performance Points cap without going over and getting disqualified.
Calibrated against real GT7 reference setups and a multi-tuner validation suite. Setups are strong, physics-based baselines — not lap-tested guarantees. Always fine-tune at the wheel.
Free to explore. Pro for every car.
Every feature works on both tiers. Pro just unlocks all 579 cars — that's the only difference.
Free
£0foreverFully tune your demo car (GR Supra Race Car ’19) plus this week’s Daily-Race cars.
Start freePro
£14.99/yrFully tune every car — all 579, permanently. ≈ £1.25/mo, billed annually.
Get early accessEverything else is included on both tiers
- Full setups — any PP, weather & drive style
- Tune Troubleshooter — diagnose handling
- Setup Balance score
- Unlimited saved setups
- Publish, browse & comment in the Community
- This week's Daily-Race meta setups
- Browse every car & track
- Free engine & content updates
Prices shown in GBP and localised at checkout. Cancel anytime — subscriptions are managed by Apple / Google.
A complete setup is one tap away.
Join the early-access list. Be first when Purple Delta hits the App Store and Google Play — and help shape what we build next.
No spam. Launch updates only — unsubscribe anytime.