Engine:
- Type: Nissan RB20DET-R
- Configuration: 2.03L inline-6 DOHC 24V with EFI
- Aspiration: Garrett T3/T04E turbocharger (1.7 bar)
- Interesting fact: Won the 1990 ATCC through driveability and determination, not power.

Pros:
- high top speed
- turbo comes alive faster than on the RS500
- good aero balance
- 50 kg lighter than an RS500
- good brakes (with 4-channel ABS for BoP)

Cons:
- turbo lag
- boost comes on like a light switch
- weaker midrange acceleration than RS500
- only 5 gears and few final ratios
- almost no downforce
- narrow tyres

Deactivated feature:
We removed HICAS rear wheel steering because it limited agility, making it a second slower and less predictable to drive. HICAS on the HR31 steered up to 0.5° in the same direction as the front wheel in real life.
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Credits:
Base mod: RJE with the following ACTK edits (v1.6)
- fix colliders.kn5
- fix colliders.ini
- fix tyres.ini
- fix cameras.ini (F6 cameras)
- add wipers
- add new LODs
- add skin AO
- reworked taillight

TTM League Edits by Flow:
- painted side bumper strips to complete side numbers for the default skins

TTM League Edits by Valentin K (v1.6.1 for TTM 2025):
- new tyres: TTM 2025 season standard with recalculated angular inertia
- new engine: new RB20DET-R replica developed in Automation + custom inertia
- new weight: 1160 kg (+ driver), the realistic minimum for an HR31 Group A
- new aerodynamics
- new brakes
- recalculated angular inertia of wheels, and recalculated unsprung hub mass
- new gears & final ratios from FISA homologation
- added HICAS rear wheel steering up to about 0.5° in same direction as front
- reworked rear blinker texture to add rear fog light
- reworked gauge texture to make it work with Multichannel Emissives
- added demo skin with uncovered headlights (only in game, not in showroom)
- added CSP blinkers, reversing light, highbeam, and EXTRA A rear fog light
- added CSP exhaust smoke & flames
- added CSP dash lamps
- TO DO: damage/dirt textures
- MAYBE: steering ratio from FISA homologation

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DONE Original gears: Page 6/91
DONE Original final drive alternatives: Page 10/91
DONE 2000 GTS-R gears: Page 37/91
DONE 2000 GTS-R gears alternative: Page 75/91
DONE 2000 GTS-R Final drive: Page 38/91
DONE 2000 GTS-R Turbo: Page 33/91
Steering: Page 38/91
DONE Brakes: Page 77/91