With the usual US Army/US Navy rivalry, the US Army decided it must have racing aircraft, Curtiss building for them two examples of the R-6 developed from the US Navy's CR. The R-6s were considerably cleaner than their predecessors, and a major contribution to drag reduction was the introduction of wing surface radiators. With these aircraft the US Army gained first and second place in the 1922 Pulitzer race, and twice raised the world speed record, the second time to 380.74km/h.