What Kart Racing Suits are the Best for my Son for Go-Cart Races

Karting suit does not really require fire retarding material; NOMEX as that mentioned above. NOMEX motor racing suit is not as durable as Nylon based material karting suit but it doubles the price or more.

Here are some of the homologation standards should take note;
1. FIA-CIK (FIA karting suit standards)
2. FIA-RS00xxx (FIA fire retarding suit standards for motor racing )
3. SFI 3.2A/x (SFI Foundation Specification fire retarding suit standards for motor racing)

So back to the question you have, if decided going for sanction events it would be better go for FIA-CIK suit else any karting suit that is comfortable, fitting the budget and nice looking will meet its objective.

Nylon based karting suits also have varieties of layer 1,2,3 and that simply means how many layers of that suit is made of. Example, FIA-CIK layer 3 suit will withstand longer time of scratching from the outer layer-to inner layer-to skin should accident happens (lets hope this would not happen). Needless to say, more layer hotter it is la.