what are the downsides to removing the overflow coolant tank but keeping the AST?

can this be done?

someone explain it in detail, i'm on a weight reduction/engine bay simplification frenzy

 

um, your coolant needs to have the overflow, or it will just spill into your engine bay.. you can remove the AST, but you HAVE to have an overflow, you can't race ANYWHERE without one anyways. Plus its plastic and weighs nothing.