The Corsair in the background is a Pica ART (scratch and dent) with an old beat up ASP .32 It weighs about 3 pounds and is very stable for a small warbird. It is considerably larger than the mustang but also appears to fly very fast, My best guess of it's actual speed is about 100 mph, (avg lap times compared to the mustang and my diamond dust and math estimates based on 8-6 prop) There is room for some more speed in the corsair but the big round frontal area limits it. It is very easy to fly. The cleaner airframe of the mustang and wing shape make it a faster plane.
The catapult works great and is from a kit by WarBirds Ltd.
www.warbirdsltd.com Don't use this catapult with a foam plane as it will tear it appart. even without engine running it provides enough power to fly the little mustang or corsair a good 75 to 100 feet. My takeoffs using the catapult are at about 1/2 throttle to reduce the torque of the engine twisting the plane during launch and I then power up after it starts flying.
One thing I've noticed is that a small warbird going 100 mph looks much faster than a big IMAC going 125+ mph.
Speed and size are relative.
Tom