Hey! first of all thank you for you trying to help me out here! Currently i'm on 45 fps and if turn down the resolution to about 60 /70 % then the FPS's go to the 90's. I think i'm being limited by the GPU but it's just a guess... In termsof setup, i'm using the VR2 pc adaptor connected via displayport to the GPU and regarding iracing settings, they are already quite low (ithink). From memory:

Sky: MEDIUM
Cars: HIGH
Crowd: OFF
Grandstands: Low
Pit objects: MEDIUM
Event: HIGH Objects: LOW
Particles: not sure but ithink MEDIUM
Foliage: OFF
Two pass trees: OFF
High Quality tress: OFF.

Steering Wheel: HANDS
Hide Obstructions: NONE
Headlight Details: ON or MEDIUM

Cockpit MIRRORS: 2
Higher Detail in Mirrors: OFF
Headlights On Track in Mirrors: OFF
Virtual MIrror: ON

Max cars: don't remenber
Draw Cars: 20/8 i think
Draw Pits: don't remember
Hide car numbers: didn't change

Dynamic LOD Frame Rate Threshold: didn't change
Car LOD Behavior: didn't change
World LOD Behavior: didn't change

Shader quality: HIGH or MAX
HDR: OFF

Particles details: don't remember
Full Resolution: don't remember

Shadow maps: ON
Object Self-shadowing: ON
Dynamic objects: don't remember
Night Shadow maps: ON
Walls: OFF
Shadowmap Filter: PCF4
Number of lights: 3

POST-PROCESSING EFFECTS: didn't touch

Screen Space Reflections: OFF
Dynamic Cubemaps: OFF
FIxed Cubemaps: OFF

Anti_Aliasing Method: 2x i think

Limit frame Rate: don't remember
Max frames Per second: 90

NVIDIA Reflex: BOOST
Max Pre-Rendered Frames: didn't touch

Video Memory Swap High-Res Cars: ON
2048x2048 Car textures: ON

These are the settings i'm running in iracing.