Early war fighters, what was supercharged and what wasn't?

[MikeGazdik]

It's my understanding the P-47 was a fuel hog, consuming roughly twice as much fuel to cover the same distance as the P-51. Some of the fuel consumption can probably be attributed to the massive aircraft size and weight, which to some extent was necessary to accomodate the turbocharger installation.

A P-47 designed for a mechanical supercharger is likely to be smaller and lighter. The end result is likely to be improved range.

The P-47 has 2,800 cubic inches, the P-51 1,650 cubic inches, which is almost twice the amount of cubic inches. So it should consume almost double the fuel.

Somewhat agree on the smaller and lighter aspect of a mechanical supercharged Thunderbolt. Take away 1/3 of the lower cowling all the way back to just before the tail wheel. The belly of the plane would be nearly flush with the bottom of the wing. Most of this extra area is dedicated to the turbo installation. Im sure we are talkiing 1,500 lbs of extra metal structure and ducting.

A engine such as this would have a Corsair look to the front, unless the oil coolers were put under the engine as in the Hellcat.

Anyways, I still would argue the plane would have more range. When properly utilized, it is very hard to beat the economy cruise that the turbo offered.

 

[davebender]

Somewhat agree on the smaller and lighter aspect of a mechanical supercharged Thunderbolt. Take away 1/3 of the lower cowling all the way back to just before the tail wheel. The belly of the plane would be nearly flush with the bottom of the wing. Most of this extra area is dedicated to the turbo installation. Im sure we are talkiing 1,500 lbs of extra metal structure and ducting.

A engine such as this would have a Corsair look to the front

Makes me wonder why the U.S. Army Air Corps did't just purchase a version of the F4U equipped with a 2 stage mechanical supercharger and without the folding wings.....

 

[MikeGazdik]

I would have loved to see the Corsair mix it up in large scale with the Luftwaffe.

But the reasons I think it never happened are these; The Thunderbolt was better at the high altitudes the escorts had to fly to cover the bombers. And that was because of the turbocharger. An bigger reason may be the fact of not being able to produce enough of them to provide the Navy, Marines, and Air Corps with planes. Then throw in contract agreements with Republic and we can start going down dark alleys we don't really want to visit.


How nice would the Mustang airframe had been with a turbosupercharged installation?

Does anyone know if the Luftwaffe experimented with turbos? I cannot recall anything they used with them. Not even the Brittish. ????

 

[Milosh]

Mike, the Focke-Wulf Fw 190-V18/U1 and the Bv 155C-O.

 

[davebender]

I don't buy this excuse. Germany produced 1,000 Me-109 fighter aircraft per month despite being pounded by heavy bombers around the clock. Multiple factory complexes were involved and they belonged to more then one corporation. The U.S.A. can match this production accomplishment with the F4U if they chose to do so.

 

[MikeGazdik]

I don't buy this excuse. Germany produced 1,000 Me-109 fighter aircraft per month despite being pounded by heavy bombers around the clock. Multiple factory complexes were involved and they belonged to more then one corporation. The U.S.A. can match this production accomplishment with the F4U if they chose to do so.

You probabley are correct. First like I mentioned, I am sure there were politicians taking care of big business. Making sure Government contracts were spread around. Secondy, I think it really is a gift of American free enterprise. The U.S. didn't need, nor want, to put all her eggs into one basket / 1 fighter. It was rather nice to be able to choose from 8 or so front line fighters!

 

[davebender]

P-38
P-39
P-40
P-47
P-51 (eventually)

I count 5. Anyway.....
The U.S. Army got by with a single medium tank for most of the war. The Army Air Corps would have done well to replace the P-38, P-39, P-40 and P-47 with variants of the F4U. You might even build a long range bomber escort version ILO of P-51.

 

[Shortround6]

Except the F4U couldn't really do the P-47s job. THe F4U-1 was not really a 25,000-35,000ft fighter and one has to wonder what the F4U-1 range would have been like if flying at over 25,000ft trying to escort turbosupercharged bombers.

THe F4U-1 does post some very good range/endurance numbers at 5500ft but that is at an altitude where the first stage of it's supercharger isn't even connected and so is using ZERO power.

In order to have fighters at the front in large numbers the decision as to which fighter a factory is to make has to be made well over a year before the fighters get there.

Edit>
By the way, since you are proposeing the F4U I would guess that counts as a first line fighter so the count is 6, and since the F6F is so close that makes 7, are the later F4Fs fist line? P-61 night fighter makes it either 8 or 9.
<edit

 

[davebender]

Not the historical naval model. But the army long range bomber escort version would have a different supercharger and probably a few other modifications also.

 

[Shortround6]

But then you are back to a P-47.

THe R-2800s used in the F4U and F6F used a rather sophisticated supercharger. They had an engine driven supercharger just like the one on a P-47. But instead of the P-47s turbo their auxilary stage was mechanically driven. Unlike the Merlin however their auxilary stage was disengaged (not turning) for take-off and low altitudes and used up ZERO power and caused no extra heating of the intake air. At a ceratin altitude the Supercharger was clutched in at low gear and provided pressuized air to the main supercharger through an intercooler. At an even higher altitude the the auxilary supercharger was shifted to high gear. In high gear the auxialry supercharger could use up over 300hp of the engines GROSS power leaving that much less for the propelller. The Turbo on the P-47 didn't do that.
Sticking an extra gear on the navy style supercharger ( making it a 3/4 speed vrs the 2/3 speed it was) could get you a higher critcal altitude than the historic engines but only at the cost of using up even more power. Sort of a diminishing returns. a few hundred more HP a few thousand feet higher up but still several hundred HP behind the P-47.

The P-47 was actually a rather streamlined aircraft for all of it's bulk. Some of it's published drag co-efficents are less than than the F4Us and F6Fs.

 

[davebender]

Are you saying the USA was incapable of producing a compact and inexpensive mechanical supercharger similiar to those used on British and German aircraft engines?

 

[Shortround6]

Are you saying the USA was incapable of producing a compact and inexpensive mechanical supercharger similiar to those used on British and German aircraft engines?

In a word; NO

Longer version. NOBODY could build a compact and cheap supercharger that would offer high altitude performance.

No compact and cheap supercharger could perform like a Turbo- supercharger could.

If what is wanted is a low altitude engine (20,000ft and below) then it is no trick at all to build a single stage (single impeller) supercharger with a single speed, two speed or variable speed drive with no intercooler.
Compact and cheap, used on thousands of R-2800s in B-26 bombers and A-26 bombers, also C-46 cargo planes and a host of other aircraft.

If you want performance at 20-30,000 you need a two stage supercharger (two impellors) and an intercooler.

If you want performance over 30,000ft you had better use a turbo-charger ( a second supercharger charger powered by an exhaust turbine) feeding your engine driven supercharger.

Or maybe you use Nitous oxide (GM 1) with your coompact, cheap superchargerexcept you now have the weight of the tank and Nirious oxide (and bulk) and while it does help peak performance it doesn't do a lot for long range cruise at altitude.

 

[MikeGazdik]

P-38
P-39
P-40
P-47
P-51 (eventually)

I count 5. Anyway.....
The U.S. Army got by with a single medium tank for most of the war. The Army Air Corps would have done well to replace the P-38, P-39, P-40 and P-47 with variants of the F4U. You might even build a long range bomber escort version ILO of P-51.

And
F4f
F4U
F6F
That is 8 front line fighters. Obvioulsy several were early war aircraft that were superceded by other U.S. and European / Japanese aircraft.

But rather than the U.S. ONLY having continuously upgraded P-38's, P-39's, P-40's and F4F's, we were able to replace those aircraft with completely new designs that were better.

I would say the P-38 was replaced by the P-51 Mustang. The P-39 and P-40 by the P-47 Thunderbolt, and the F4f by the F4U Corsair and the F6F Hellcat.

 

[maxs75]

Can you provide a list of WW2 planes with TURBO supercharged engines?

Probably it will include:
P-43
P-47
P-38

B-29
B-17
B-24

What else?

Max

 

[Shortround6]

P-61C's and B-32s.

German JU 86Ps.

A large variety of experimental and prototype aircraft.

 

[renrich]

Vought developed a turbo charged version of the Corsair but decided that the performance gains at high altitude did not warrant the performance losses at lower altitude. A discussion about developing an AAF version of the Corsair has taken place on this forum before. In fact several times. There is little doubt that a Corsair version redesigned for AAF use could have been very successful. The early F4U1 had a lot more internal fuel capacity than the P47 and without any modifications could have escorted bombers further than the early P47, plus it was ready for deployment earlier than the P47. Quite a few non folding wing Corsairs were built by Goodyear but other modifications to the Corsair design because the design would not have needed the structural strength for carrier landings would have meant more weight savings and performance and range gains. As far as altitude performance is concerned, the P51B had a two speed, two stage supercharger, just like the Corsair and seemed to have been adequate for high altitude bomber escort. The Corsair engine was optimised for low and medium altiude performance, where most combat took place in the Pacific, but an F4U1D caught and destroyed a Japanese recon plane at 380000 feet so it's performance was not shabby at high altitudes. I suspect that the reason the Corsair was not considered for use in the AAF was that there was a rivalry between the Army and Navy and the prevailing attitude was that no fighter designed for carrier duty could compete with a land based design.

 

[riacrato]

You pay for a lot of extras in a carrier fighter that you don't need in a landbased one. And I'm not only talking about extra gear, I'm talking about structural design features. Why would you bet on that horse if a P-51 can do the same or better and cheaper?

 

[renrich]

You would not want to substitute the Corsair for the P51B because a Corsair could never have the range of the Mustang. An argument could be made though that the Corsair could have substituted for the P47 because it was available earlier with longer range. The Corsair would have been phased out as an escort fighter just like the P47 was and the Corsair would have been superior to the P51 in ground attack.

 

[tomo pauk]

(thread skew alert)
How much range the escort job needs, ETO WW2?
F4Us could do 1000 mi with internal fuel, P-51D was able to make 1600 mi with drop tanks. So the Corsair with drop tanks is as good as Pony, but feasible some time before.

 

[Shortround6]

Check the ranges at speed and altitude. Many Navy planes were rated for range at low altitudes meaning they weren't using power (fuel) to turn the first stage of their two stage superchargers. They were also sometimes rated at a rather low speed which, while safe enough for long over water flights with no air defenses below might not work out so good over Europe.

See: http://www.zenoswarbirdvideos.com/Images/F4U/F4USEC.GIF

While the Corsair may be able to fly using under 50 gals an hour at low altitude a high speed cruise could almost double that and note that at MAX continuous power (no time limit) fuel consumption is 250 gals an hour at high altitude.

What was the combat radius of the planes in question at operational heights and speeds?