The Curtiss P-5 (company designation Model 34L) was the designation given to a version of the P-1 Hawk that was powered by a turbosupercharged Curtiss D-12 engine. At the request of the USAAC, five airframes identical to the P-1A had the 435 hp turbosupercharged V-1150-4 (D-12F) engine installed and were designated P-5. The turbosupercharger was mounted externally on the left hand side of the fuselage.
Five examples of the P-5 were ordered on May 14, 1927. Serial numbers were 27-327/331. The first example was delivered in January 1928. The high altitude performance showed a marked improvement over that of the standard P-1A. The top speed of the P-5 was only 142 mph at sea level, but it increased to 173.5 mph at 25,000 feet. The aircraft could climb to 10,000 feet in 8.4 minutes. Initial climb rate was 1250 ft/min. The service ceiling was 31,900 feet, almost ten thousand feet greater than than of the P-1B. Weights were 2551 lb. empty, 3340 lbs. gross. Armament was the same as that of the "standard" P-1, namely a pair of 0.30 cal machine guns mounted in the upper fuselage cowling synchronized to fire through the propeller arc.
Although the P-5 exhibited a much better high-altitude performance than the standard P-1, the general feeling on the part of the Army was that it would be better to wait for the arrival of the more powerful Conqueror engine rather than to go ahead with a large procurement for series production of the P-5. Consequently, only five P-5s were built. Two of the five P-5s were destroyed during the test program, but the surviving three planes entered service with the 97th Pursuit Squadron. They remained in service until mid 1932. The survivors were sent to mechanic's schools in August of 1932.
Curtiss chose the name "Superhawk" for the P-5, but I don't think that this name was ever official.