How change the size of title?

i need change the size the 'abstract', only the title must affect the content must remain intact, I want a letter size 20

\documentclass[11pt,letterpaper]{report}
%\usepackage{etoolbox}
\usepackage{titlesec}

\begin{document}

\begin{abstract}
El principal mecanthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis introthis intro
\end{abstract}
\section{Exp}
this Exp SECTION
\tableofcontents
\chapter{ETAPA2}
\label{cap:experimental}
this intro

\section{Exp2}
this Exp SECTION

\end{document}

• Try just \chapter*{\protect\Large ABSTRACT} without the \titleformat and \titlespacing commands there. – koleygr Mar 13 at 2:54
• Off topic: Why don't you use \begin{abstract} and \end{abstract} and do some settings there? – JouleV Mar 13 at 2:55
• @JouleV by the margins and the title space with the content – x-rw Mar 13 at 2:56
• Of course, that is why I said "do some settings there". I don't consider an abstract as a chapter in a book. – JouleV Mar 13 at 2:57
• @x-rw You should have a look at tex.stackexchange.com/questions/82993/… and tex.stackexchange.com/questions/151583/…. – JouleV Mar 13 at 3:01

\documentclass{report}

\usepackage{lmodern,lipsum}

\renewcommand{\abstractname}{%
\fontsize{20}{24}\selectfont\bfseries SECCI\'ON RESUMEN}

\begin{document}

\begin{abstract}
\lipsum[1]
\end{abstract}

\end{document}

• thanks, but What is the meaning of 24? – x-rw Mar 13 at 3:27
• @x-rw: \fontsize{<size>}{<baseline skip>} sets both the font <size> and the skip between the baseline of successive lines (called the <baseline skip>). \fontsize{20}{24} sets a 20pt font size with a slightly (20%, 24pt) larger skip between baselines. It's not really necessary here since you're only setting a single "header"/title and therefore won't have multiple lines of text that could interfere with one another. See, for example, this minimal example that yields this output. – Werner Mar 13 at 3:40
• yes it's ok, and how would I change if I want to use 'large', 'Large', 'LARGE' – x-rw Mar 13 at 4:00