Very cool. Looks like you are into race cars? I so wish I had this printer when I was building vintage race bikes ... jeez it could have saved me some time and money coming up with small to medium pieces like that.
So far I'll typical go with four walls thick, or 100% infill on things that need to be tapped, has worked great.
Are those PLA or PETG? I was amazed at the strength of these parts when printed right, previously I was under the impression everything would be pretty fragile.
Printed this NEMA 23 motor mount for my CNC project out of PLA with I think 50% infill, four walls. A bit of warping in that corner as I forgot to cover the HVAC vent that blows right on the printer, printed at 70mm/second and 0.35mm layer height .. so I was pushing things a bit. Turned out very strong and perfectly usable. Also printed up a 1/8" isolation spacer out of black TPU.