We propose to investigate the hyperkagome antiferromagnet Na4Ir3O8. Here the magnetic Ir4+ ions lie on a three-dimensional network of corner sharing triangles and interact with each other via highly frustrated antiferromagnetic interactions. Heat capacity and susceptibility measurements reveal the complete absence on long-range magnetic order to 2K despite the large Curie-Weiss temperature of 650K, and suggest the presence of gapless magnetic excitations indicative of a spin-liquid ground state. Here we plan to perform the first inelastic neutron scattering measurements of Na4Ir3O8 to explore the magnetic excitation spectrum.