SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
I'd trade my wife for a P-40 any day. I'll even throw in $20.
P40 Vs all other fighters in Europe
- Thread starter denny
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
By Dec 1941 many things were in progress. The P-39 had been tried in Europe and was being sent to Russia. The Hurricane already was in Russia. The P-40 was in service in N Africa. The first Mustang Mk Is had just arrived in UK. The B-17 had performed its first raids in Europe. Perhaps most important Lease Lend was in place to allow for all this to happen.
Care to elaborate?
Do we know any aircraft where a jump from a 1-stage V12 to a 2-stage V12 failed to bring a major improvement both in RoC and speed?
Is there a problem that P-38K solves, for Allies in general, and for P-38s in particular?
I'd try with extra fuel tanks in front of the ammo boxes on the P-40.
With Griffon - excellent IMO. We'd probably see the comparable turn of speed as with the Spitfire with same engines, unless the radiator set-up is botched.
FWIW, the XP-40Q2 (the last of the P-40 versions, with the 2-stage supercharged V-1710 + water injection and the bubble top) was faster than Fw 190A, about as fast as Fw 190D-9, and about 20-25 mph slower than Spitfire 14 or P-51D (all for ~20000 ft altitude).
Shortround6
Lieutenant General
The P-40 was actually good for about 2 years, 3 is stretching it. And it was fortunate that some of the Early P-40s did not have to be used in combat as built in 1940.
A Late 1940 P-40 was coming off the line with Spitfire IIs and Hurricane IIs. (Merlin XIIs and Merlin XXs). This is why the Tomahawks went to NA. The RAF didn't want them in England.
Of the Tomahawks that stayed in England one has to compare to what the RAF was flying in 1941. The Squadrons that were flying them were NOT flying Spitfires or Hurricanes in the summer of 1941. The majority of Army cooperation squadrons flying Tomahawks were trading in Lysanders. Most anything was going to look to those pilots.
The P-40D/E was a very useful improvement. But its was a lot heavier without much improvement in power and Spitfire Vs were showing up months ahead of the P-40D/E. A Spitfire V was well over 1000lbs lighter than a P-40D/E. Normal gross was about 7787bs with 120 US gallons for a British P-40D. The P-40E with 6 guns (and other changes) grossed 7950lbs (still with 120 US gallons of fuel).
The P-40K showed up in May of 1942 (at the factory) and got the 1325hp engine for take-off but power above 12,000ft or so wasn't any better than the older versions (the P-40F did slot in here in Jan 1942 but production was very slow to get going.) Please note that In August of 1942 the RAF was using 4 squadrons of Mustang 1s, 2 squadrons of Spitfire MK IVs with two stage Merlins and 3 squadrons of Typhoons.
The P-40 did provide good service but it was always a plane that was going be used until something else was available. (the Army had ordered hundreds of P-47s before the 500th P-40 made it out the factory door).
A Late 1940 P-40 was coming off the line with Spitfire IIs and Hurricane IIs. (Merlin XIIs and Merlin XXs). This is why the Tomahawks went to NA. The RAF didn't want them in England.
Of the Tomahawks that stayed in England one has to compare to what the RAF was flying in 1941. The Squadrons that were flying them were NOT flying Spitfires or Hurricanes in the summer of 1941. The majority of Army cooperation squadrons flying Tomahawks were trading in Lysanders. Most anything was going to look to those pilots.
The P-40D/E was a very useful improvement. But its was a lot heavier without much improvement in power and Spitfire Vs were showing up months ahead of the P-40D/E. A Spitfire V was well over 1000lbs lighter than a P-40D/E. Normal gross was about 7787bs with 120 US gallons for a British P-40D. The P-40E with 6 guns (and other changes) grossed 7950lbs (still with 120 US gallons of fuel).
The P-40K showed up in May of 1942 (at the factory) and got the 1325hp engine for take-off but power above 12,000ft or so wasn't any better than the older versions (the P-40F did slot in here in Jan 1942 but production was very slow to get going.) Please note that In August of 1942 the RAF was using 4 squadrons of Mustang 1s, 2 squadrons of Spitfire MK IVs with two stage Merlins and 3 squadrons of Typhoons.
The P-40 did provide good service but it was always a plane that was going be used until something else was available. (the Army had ordered hundreds of P-47s before the 500th P-40 made it out the factory door).
Greg's Airplanes and Automobiles on Youtube has a recent video on the P40.
I don't know how to make the movie work here but a link is below.
General things I've read here involve how it's use started before Dec 1941 when the USA was not putting a lot of money into research. The British used it in North Africa in 1941 and they were trying to use it with dogfighting tactics that it was not totally successful at. Then it was Lend Leased to Russia and their airforce had been hit hard by Germany so pilot skill and tactics could have suffered there also.
Greg's video linked above impressed me with how all the added boost and power only increased top speed 20-25mph. That was in part because it still ran out of power before it was able to benefit from reduced drag up high due to the single stage supercharger situation.
wuzak
Captain
Using higher boost reduces the critical altitude.
The big power numbers mentioned were very low altitude.
Shortround6
Lieutenant General
There seems to be some sort of disconnect with some of the P-40 numbers.
A lot of P-40 numbers are at reduced loads.
Like not even using the full internal fuel you can put in the existing tank tanks. In fact many of the P-40Ls and a the first 200-400 P-40Ns (the fast one) didn't even have the forward wing tank installed.
For instance test of the P-40N (actually a P-40K modified to duplicate the P-40 as much as possible) was run at 7413lbs. One book claims that the P-40N-1 had an empty weight of 6000lbs with a useful load of 1740lb and normal gross weight of 7740lbs. The test plane was 300lbs light.'
This was with four guns and 235rpg and all the weight saving tricks, like taking the electric starter (and a much smaller battery) out. By the time you get to the P-40N-5 the normal weight has gone back to 8300lbs and that is clean, no drop tank or bomb.
BTW the P-40F has a gross weight of 8505lbs with 235rpg and with only 119US gallons on board. With more ammo, extra oil and the front wing tank full of fuel the gross weight goes to 8860lbs.
I don't know what you have to take out of a P-40 but the plane is overweight.
I would note that the Pilots manual for the P-40F and L have a misprint in the specific engine flight chart. While the war emergency section of the chart shows 61in of manifold pressure compared to 48.2in in military power the power/listed seem to be the same power as the take-off power. One wonders how fast the P-40F & L would have been 1435hp at 12,000ft or so.
- Thread starter
- #29
That was a GREAT Video.
Thank You
There was a question on the comments similar to mine here.
This was Greg's Response
Greg's Airplanes and Automobiles
3 weeks ago
The P-51 was superior at high altitude in part due to the newer wing design's higher mach limit.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
The P-40 had it's genesis pre-war.
At the rate that aircraft design and technology was advancing during the war, the P-40 was not going to be able to keep up.
The only viable alternative was the XP-60C, and even that was eclipsed by the P-47.
At the rate that aircraft design and technology was advancing during the war, the P-40 was not going to be able to keep up.
The only viable alternative was the XP-60C, and even that was eclipsed by the P-47.
Thank you for running the numbers.
The overweight part I can agree. A way around being heavy was to install a superior engine that also excels at high altitude, so the performance figures are not just restored to the 'old' values, but improved by a great deal. That never happened to the P-40.
That it was an obsolete airframe (comment from the same sentence that I've quoted above) is dubious IMO.
Boost of 61 in Hg = +15 psi. We can see here the Merlin 20 series making 1400 HP at +14 psi at 12000 ft, and almost 1500 HP at ~6000 ft. So I'm not sure what to make from the WER figures from the engine table from P-40F manual, apart that these figures are wrong.
P-51 was superior vs. P-40 at all altitudes due to indeed being a newer design with a much lower drag. Superiority at high altitude was a result of having the 2-stage supercharged V-1650-3 or -7 in the nose atop of all that.
I'd wager to say that an increase in top speed of 20-25 mph is a very good increase. Eg. that was the difference in speed between the Fw 190 and Spitfire V, or Hellcat vs. Zero.
Last edited:
Not exactly the same point but similar, a difference of 25-30MPH gave superiority in almost all cases, even a top ace cant make up the difference.
Please excuse but what do you mean with "turn of speed" and "the radiator set-up is botched"?
Afaik the max speed of the D-9 was the best of the fighters mentioned at about 20.000 ft.
Last edited:
"Turn of speed" - a fancy way to say "speed".
Something "is botched" = something is messed up, or something is badly made. A botched radiator set up can add a lot of drag.
At 20000 ft, the D-9 seem to do do ~415 mph in flight tests, and ~430 mph per FW calculations. XP-40Q-2, per test, was making 418 mph there. The Spit 14 did 425 mph at 20000 ft, granted above 20000 ft it was much faster.
In English idiom a turn of speed is short lived and above normal. Like an athlete who has a "kick" to the finish line, or a football (soccer) player who can change pace in one or two strides but may not be actually a fast runner. In aviation terms it would be the speed at maximum power above max continuous, or could be applied to something like a P-47 with rapid dive acceleration.
Have to find the chart again but I'm sure that at 5500 m the max speed of the D-9 was 703 kmh/438mph, the same max speed of the P-51D at higher altitude.
Can you tell where the Focke Wulf test results compared to calculations were mentioned?
33k in the air
Staff Sergeant
- 1,356
- Jan 31, 2021
For what it's worth, according to the Pilot's Flight Operating Instructions for the P-40N, at 8,400 to 6,600 lbs weight, with no external ordnance, and set for maximum range, at 25,000 feet it could get 5.953 air miles per gallon (256 TAS / 43 GPH). The P-51D, at 9,600 to 8,000 lbs weight, with only wing bomb racks fitted, and set for maximum range, at 25,000 feet it could get 5.865 air miles per gallon (305 TAS / 52 GPH).
It would seem the aerodynamics of the P-40 were not that bad.
Shortround6
Lieutenant General
For the people that want to use the P-40 with a different engine the XP-40Q does offer some food for thought.
1, The XP-40Q was tested at 9000lbs with 160 US gallons. The weight of 4 .50cal guns and 235rpg was simulated by ballast (they may have had mock ups/gun fairings in the wings)
2. The XP-40Q used about 1700hp at 20,500ft to reach 422mph. This required over speeding the engine to 3200rpm.
3. A P-51B needed about 1400hp at 22,000ft to reach 417mph. It could go faster high up, The XP-40Q could not. They had no inter cooler and were using water injection for charge cooling and power was fading slightly at 22,000ft.
The Allison engine was supposed to weigh about 1515lbs but trying to figure out how much coolant and oil was needed for various engines does get tricky. Trying to squeeze in a 2 stage Griffon was probably out of the question. The single stage Griffon was not going to make the power needed at over 20,000ft.
1, The XP-40Q was tested at 9000lbs with 160 US gallons. The weight of 4 .50cal guns and 235rpg was simulated by ballast (they may have had mock ups/gun fairings in the wings)
2. The XP-40Q used about 1700hp at 20,500ft to reach 422mph. This required over speeding the engine to 3200rpm.
3. A P-51B needed about 1400hp at 22,000ft to reach 417mph. It could go faster high up, The XP-40Q could not. They had no inter cooler and were using water injection for charge cooling and power was fading slightly at 22,000ft.
The Allison engine was supposed to weigh about 1515lbs but trying to figure out how much coolant and oil was needed for various engines does get tricky. Trying to squeeze in a 2 stage Griffon was probably out of the question. The single stage Griffon was not going to make the power needed at over 20,000ft.
Users who are viewing this thread
Similar threads
