Any idea how to translate sweat equity'
It might help if the term is defined.:
Sweat equity is a term used to describe the contribution made to a project by people who contribute their time and effort. It can be contrasted with financial equity which is the money contributed towards the project. It is used to refer to a form of compensation by businesses to their owners or employees. The term is sometimes used in partnership agreements where one or more of the partners contributes no financial capital. In the case of a business startup, employees might, upon incorporation, receive stock or stock options in return for working for below-market salaries (or in some cases no salary at all).
Possibly "equidad de sudor" in Spanish. That is a direct translation. Maybe a native speaker has a better term for it.