Saville wrote:
C VEICH wrote:
The Hellcat is definitely not a sleeker airframe than the Jug and it has considerably more wing area which may account for the slower top speed. I do find it hard to believe that a Jug will outclimb a Hellcat though. More wing and less weight always results in a better climb.
Well unless the P-47's turbocharging has an effect at altitudes where the F6F's charging doesn't have an effect....or has less effect.
Basically this - the previous post of airspeeds for the two aircraft seem to reference Wikipedia, which had a stated altitude for the max Jug speed at 29,000'!!
At these altitudes the GE turbosupercharger absolutely has a huge advantage over the fixed two stage supercharger of the F6F. The Navy (and Grumman) had the technical knowledge and funds to incorporate a turbosupercharger, but neither wanted to do so due to reliability and maintenance concerns based around carrier operations. Indeed not a single naval fighter (no matter how complicated) ever featured this technology.
For example, some early numbers I found said the hellcat's top speed at 18,700 was 371mph, but climbing to 24,000 drops you down to 330mph. The P-47's were able to operate at extreme manifold pressures later in the war - I'm talking around and over 70". This is just not achievable with a conventional blower that the R-2800s employed. However they never really flew at those altitudes, but you'd need that height to achieve the type TAS seen here.
Actually in the P-47D you could achieve 1950bhp at 27,500ft - for a base unmodified D model this still got you 415mph TAS. With water injection, the D could achieve
435mph TAS at 31,000ft Considering you're up there with modern day jet airliners at that altitude, it's pretty incredible.
I believe power was rated at about 400hp more for the Jug, but of course it could achieve that power at any altitude, without pilot interaction or trying to remember manifold pressure and altitude curves for the blower settings.
The F6F reached peak performance at about 22,000ft and performance fell off a cliff after that (all variants, relatively speaking).
I'm not sure about climb rates - some of the best P-47s were later, including the D with the "paddle prop" and the up-rated 2,800hp engines - even then, it achieved around 3,500fpm which compares similarly to the F6F. In this case the wing area and HP plus the prop design are enough offset the weight differences of the two aircraft. This would likely be at low altitudes though, and here the Jug just benefited from getting hugely powerful R-2800 variants later in the war.