Like JM said, PLA has one of the lowest, if not lowest TG temperatures of mainstream 3d printing materials (not including TPUs or other flexible materials). It does have decent tensile strength, but is also brittle. Overall I wouldn’t use it for karting. If you want to make good parts that are robust then I would say your options are primarily: PETG, ABS, nylon, PC, or filled version of those (glass or carbon). For the most part these are In order of printing difficulty and strength (easy/weak -> difficult/strong).
It also comes down to your design and your printing process. Give yourself enough material by design and when printing use more infill and wall layers. Majority of my parts will be 90+% infill because the extra material cost and print time are less of a concern compared to part strength.
If you want a good source to compare relative material properties of available 3d printing materials look here.
My go to materials are: ABS, nylon, and CF nylon. Nylon can have its challenges, but it’s not impossible. Definitely need to make sure the material is dried and your nozzle can reach 250-260˚C.
Here’s a picture of my nylon frame sliders that have almost 2 years of use. You can also see the seat spacers are 3D printed.
And just to clarify this is all about FDM printing. SLA and other technologies will have different materials.
Hope that helps.