FWIW, my latest racing cab is using a refurb i7 16 GB Ram, 256 SSD, 2 TB Black WD, 1650 GTX for graphics. The TV is a 4k 43 TCL, most everything is in 1080 though - and I'm ok with that. It seems to play just about anything I can throw at it, although it did struggle with Forza 7 a bit.
To give you an idea of what games I'm using this for - I don't have a complete list, but offhand, here is what I play on a fairly regular basis:
Teknoparrot - SR3, Grid, Dirty Drivin, Sonic Racing, Daytona 3, Batman, GTI Mini
Sim
Project Cars 2, Assetta Corsa
Challenging arcade but not sim level
Grid (2008ish?), Grid (2019?), Grid 2, Grid Autosport, NFS Shift, Shift Unleashed
Arcade
Blur, Split Second, a bunch of NFS
The intro to this forum mentions how racing cabs aren't as easy to setup - I personally wouldn't spend $2k on a super awesome computer only to find out that you don't even need an i5 for your target games, but that's me. A friend of mine gave me a xeon desktop from 10 years ago, and with a 1030 GT it's actually cranking out just about everything - jitters only occasionally.