Here are the Forza Motorsport System Requirements (Minimum)
CPU: Intel i5-8400 or AMD Ryzen 5 1600
RAM: 8 GB
VIDEO CARD: NVIDIA GeForce GTX 1060 or AMD Radeon RX 5500 XT
DEDICATED VIDEO RAM: 3072 MB
PIXEL SHADER: 5.1
VERTEX SHADER: 5.1
OS: Windows 10 version 15063.0 or higher
FREE DISK SPACE: 130 GB

Forza Motorsport Recommended Requirements
CPU: Intel i5-11600K or AMD Ryzen 5 5600X
RAM: 16 GB
VIDEO CARD: NVIDIA GeForce RTX 2080 TI or AMD Radeon RX 6800 XT
DEDICATED VIDEO RAM: 12288 MB
PIXEL SHADER: 5.1
VERTEX SHADER: 5.1
OS: Windows 10 version 15063.0 or higher
FREE DISK SPACE: 130 GB