What would a "Best of the lot" 1943 fighter aircraft look like?

How did they get improved performance out of the fuel then?

Higher oct fuel + low-ish CR = greater boost = more power. Works for all countries' supercharged engines.
The Mikulin AM-42 with CR 5.5:1,using boost of 2 ata for 2000 HP, on Soviet 96 oct fuel, no water-alcohol injection, no intercooler.
In the same time, DB 605L has the CR of 8.5:1, and must use MW50 even when using boost above 1.4 ata + C3 fuel that was 100/130+ grade in 1945.

Why weren't they used more then in German designs? AFAIK the Jumo 211J was the first that had one.

Again - who knows? We know that Jumo 213E and DB 603LA used intercoolers (and could use B4 fuel). The 213F, 603L and 605L did not, the last two needed C3 fuel and MW50 to operate at hi-power settings, 213F used B4 + MW50.
 

Deleted member 1487

Higher oct fuel + low-ish CR = greater boost = more power. Works for all countries' supercharged engines.
The Mikulin AM-42 with CR 5.5:1,using boost of 2 ata for 2000 HP, on Soviet 96 oct fuel, no water-alcohol injection, no intercooler.
In the same time, DB 605L has the CR of 8.5:1, and must use MW50 even when using boost above 1.4 ata + C3 fuel that was 100/130+ grade in 1945.
So why were the Germans pursuing greater compression ratios?
 

Deleted member 1487

Considerably increased CR will slightly both improve power and reduce fuel consumption.
You're contradicting yourself, because you've said not increasing it resulted in greater power. How can increasing it then do that also, especially when you said keeping it low got better power, per OTL Allied designs???
 
The 'G-Lader' (spiral supercharger) was never installed in a service-worthy DB-603. Thus it is 670-680 km/h for an armed Fw 190C, while the chart represents un-armed ('ohne Waffen') test bed.

Not important since the thread only asks for 1943 possibilities. as was pointed out before.
 
You're contradicting yourself, because you've said not increasing it resulted in greater power. How can increasing it then do that also, especially when you said keeping it low got better power, per OTL Allied designs???

I am not contradicting myself.
Increased boost, made possible both by low-ish CR and hi-oct fuel, provided almost a linear rise of power. We're talking about 30-40% on basically the same engines, like Merlins or V-1710 of any kind.
In the same time, increase of CR by 10-15%, like it was done on important German engines (DB 601/605 line, BMW 801) gave increase of power of couple to several %, along with reliability problems that took many months to solve. Increase the CR by 30 to 40 % will wreck a supercharged engine of ww2 vintage.

Not important since the thread only asks for 1943 possibilities. as was pointed out before.

Did I said something wrong in the post you were quoting?
 

Deleted member 1487

I am not contradicting myself.
Increased boost, made possible both by low-ish CR and hi-oct fuel, provided almost a linear rise of power. We're talking about 30-40% on basically the same engines, like Merlins or V-1710 of any kind.
In the same time, increase of CR by 10-15%, like it was done on important German engines (DB 601/605 line, BMW 801) gave increase of power of couple to several %, along with reliability problems that took many months to solve. Increase the CR by 30 to 40 % will wreck a supercharged engine of ww2 vintage.

Did I said something wrong in the post you were quoting?
Then we are misunderstanding one another.
You're saying boost the revolutions is what achieved the Allied increased power, so only for WEP? How would increased fuel octane even be necessary to increase revolutions per second?

Edit:
https://en.wikipedia.org/wiki/War_emergency_power
British and Commonwealth aircraft could increase power by increasing the supercharger boost pressure.[5]
Did you mean the supercharger boost option? The increased boost I'm gathering means more heat, which in turns means then that less explosive fuel would be able to handle more.

Why then for WEP would higher octane fuels matter?
 
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Deleted member 1487

The FW190C: War Winning Wunderwaffe, or technological dead end?

Who knows?

And indeed, who cares?
You know this is an alternate history board and we're responding to a question about what would the best fighter of 1943 be without restriction of equipment, build quality, or fuels, right?
 
Then we are misunderstanding one another.
You're saying boost the revolutions is what achieved the Allied increased power, so only for WEP? How would increased fuel octane even be necessary to increase revolutions per second?

Boost = manifold pressure. In Germany of ww2 and earlier expressed in ata, in UK in +psi, in USA in inches Hg. Greater boost was also used for take off, thus we have, for example, Mosquitoes and Lancasters with 1600 HP Merlins in 1944 vs. 1400 HP in 1942. Or V-1710 with 1325 HP vs. 1040. Revolutions per second were always 3000 for Merlin and war-time V-1710.

Edit:
https://en.wikipedia.org/wiki/War_emergency_power

Did you mean the supercharger boost option? The increased boost I'm gathering means more heat, which in turns means then that less explosive fuel would be able to handle more.

Why then for WEP would higher octane fuels matter?

Greater boost = more air is packed into the cylinders, that requires more fuel (end result being more power). And indeed more heat, both for the fuel/air mixture and engine itself, thus WEP being limited to 5 min mostly.
 

Deleted member 1487

Boost = manifold pressure. In Germany of ww2 and earlier expressed in ata, in UK in +psi, in USA in inches Hg. Greater boost was also used for take off, thus we have, for example, Mosquitoes and Lancasters with 1600 HP Merlins in 1944 vs. 1400 HP in 1942. Or V-1710 with 1325 HP vs. 1040. Revolutions per second were always 3000 for Merlin and war-time V-1710.

Greater boost = more air is packed into the cylinders, that requires more fuel (end result being more power). And indeed more heat, both for the fuel/air mixture and engine itself, thus WEP being limited to 5 min mostly.
The Germans had Notleistung, which was WEP, why wasn't that enough for them as it was for the Allies? So Allied engines were actually relatively lower powered except for WEP by keeping compression ratios low?
 
The Germans had Notleistung, which was WEP, why wasn't that enough for them as it was for the Allies? So Allied engines were actually relatively lower powered except for WEP by keeping compression ratios low?

Notleistung and WEP are not directly comparable. Notleistung involved increase both of boost (only slightly, by about 0.1 to 0.2 ata) and RPM, WEP was just an increase of boost (by up to as much as 0.50 ata - I'm using German units for comparison sake).
WEP in German was called 'Erhohte Notleistung' ('Increased Emergency power'), applicable mostly to the BMW 801D from mid-1943 when the equivalent of 100/125 fuel became available, where it accounted for ~0.2 ata (3psi), or around 200 HP in low level.
WEP with water-alcohol injection was called 'Sonder Notleistung' - 'Special emergency power'.
Notleistung was somethimes more than enough for the German engines, 15 months for the DB 605A lasted the ban on Notleistung for that engine.

'Allied engines' is quite a group, some of them were bigger and made more power than German engines even on low boost. Granted, Merlin and V-1710 were of much smaller cubic capacity than mainstream German engines. By using greater RPM, more boost (where indeed hi-oct fuel was a factor) and sometimes better superchargers and intercoolers, those Allied engines equaled bigger German engines and sometimes surpassed them.
 

Wimble Toot

Banned
You know this is an alternate history board and we're responding to a question about what would the best fighter of 1943 be without restriction of equipment, build quality, or fuels, right?

Hypothetical aeroplanes are ALWAYS better than actual real ones, in the minds of their proponents, who will stick to their convictions like epoxy resin.

They were never tested in combat, never flown by fighter pilots, never repaired by ground crew nor landed on airfields that just been bombed, so their proponents can make any claim they wish.

Nobody can disprove their claims of the invincibility of their favoured imaginary weapon system.
 

Deleted member 1487

Notleistung and WEP are not directly comparable. Notleistung involved increase both of boost (only slightly, by about 0.1 to 0.2 ata) and RPM, WEP was just an increase of boost (by up to as much as 0.50 ata - I'm using German units for comparison sake).
WEP in German was called 'Erhohte Notleistung' ('Increased Emergency power'), applicable mostly to the BMW 801D from mid-1943 when the equivalent of 100/125 fuel became available, where it accounted for ~0.2 ata (3psi), or around 200 HP in low level.
WEP with water-alcohol injection was called 'Sonder Notleistung' - 'Special emergency power'.
Notleistung was somethimes more than enough for the German engines, 15 months for the DB 605A lasted the ban on Notleistung for that engine.

'Allied engines' is quite a group, some of them were bigger and made more power than German engines even on low boost. Granted, Merlin and V-1710 were of much smaller cubic capacity than mainstream German engines. By using greater RPM, more boost (where indeed hi-oct fuel was a factor) and sometimes better superchargers and intercoolers, those Allied engines equaled bigger German engines and sometimes surpassed them.
Any idea why the Germans didn't use boost as much? Was it the quality of the materials, which weren't up to handling the increased pressure? Or was it that they lacked the fuels that could handle the increased boost without premature detonation, so didn't understand the right way to harness the power of the new fuels due to limited experience working with it? Or that they tried to get too much from it, thinking compression ratios were the way to go vs. boost? Sorry to throw all these questions at you, I'm just trying to understand what was going on and you seem to have a handle on it.

Hypothetical aeroplanes are ALWAYS better than actual real ones, in the minds of their proponents, who will stick to their convictions like epoxy resin.

They were never tested in combat, never flown by fighter pilots, never repaired by ground crew nor landed on airfields that just been bombed, so their proponents can make any claim they wish.

Nobody can disprove their claims of the invincibility of their favoured imaginary weapon system.
Again we are talking about a completely hypothetical ideal situation where we can mix and match perfect equipment and don't have to rely on what was in service; if we did this thread would be "what was the best of the lost historically in 1943" rather than "what would a best of the lost 1943 fighter aircraft look like". Complaining about hypothetical options in a hypothetical what if thread is rather bizarre.
 
Any idea why the Germans didn't use boost as much? Was it the quality of the materials, which weren't up to handling the increased pressure? Or was it that they lacked the fuels that could handle the increased boost without premature detonation, so didn't understand the right way to harness the power of the new fuels due to limited experience working with it? Or that they tried to get too much from it, thinking compression ratios were the way to go vs. boost? Sorry to throw all these questions at you, I'm just trying to understand what was going on and you seem to have a handle on it.

Possibly a combination of factors. Materials - not so much, German engines and other hardware were used by many countries well into 1950s. They probably wanted to have the best of both worlds in small pieces - a little bit of increased boost, a bit smaller consumption (important for Germany), while not being sure that hi-oct fuel will really be available in quantities as it historicaly it was? Then we have British, French and Italian engines in air races in 1920s and 1930s, where perhaps RR got crucial lessons re. short term increase in engine power?
It might be interesting for us to compare the DB 601N with Merlin 45. Both engines were using 100 oct fuel, the Merlin went to +16 psi boost (2.2 ata, 1500+ HP) with commendable reliability, while the 601N was at 1.35 ata (+4.5 psi, or less than Merlin III or X on 87 oct fuel; 1260 PS) with questionable reliability. The 601N got increase of compression ratio vs. the 601A, 7.9:1 vs. 6.9:1.
 
Maybe not what could, but what did happen!
fisher-xp75-eagle_13.jpg


The Fisher XP-75! P-51 wings, A-24 tail, undercarriage F4U, engine Allison V-3420 and layout of a P-39.
Max speed 433mph and armed with up to 6x.50 machine guns.
First flew 1943.
 

Wimble Toot

Banned
If you want a ‘best of the lot’ fighter from 1943, I would want at least a microscopic scintilla of evidence that it was good at the job it was designed to do, namely destroy other aircraft in combat.

Reams and reams of technical data, graphs, ultimately prove nothing.

The Spitfire XIV, P-47D, Bf109G, P-51B, FW190A, Fiat G55, La-5, F6F And even the Gloster Meteor were all available in 1943, and have proven combat records.

The Martin Baker MB5 was the best fighter of World War 2, irrespective of the minor detail that it never shot down another enemy aircraft.
 
The Fisher XP-75! P-51 wings, A-24 tail, undercarriage F4U, engine Allison V-3420 and layout of a P-39.
Max speed 433mph and armed with up to 6x.50 machine guns.
First flew 1943.

The Fisher P-75 got P-40 wings and a purpose-built tail, and carried 10 machine guns.



Winkle Brown's fave Spitfire was the Spit XII, not the Spit XIV. The contra-prop Griffon was largely post-war, and the only Griffon Mustang crashed when the Griffon failed.



The argument between boost and compression overlooks the overall efficiency of the engine, which requires a balance of all factors and cannot be discussed in a meaningful fashion without great complexity, but carry on anyway. One might still look for the reason DB603s had different compression ratios left and right. Germans used motor-cannon which limited induction efficiency, while Rolls purposely ignored the feature to cater to better induction flow. Allison ignored the cannon and the best induction routing.
 
If you want a ‘best of the lot’ fighter from 1943, I would want at least a microscopic scintilla of evidence that it was good at the job it was designed to do, namely destroy other aircraft in combat.

Reams and reams of technical data, graphs, ultimately prove nothing.

The Spitfire XIV, P-47D, Bf109G, P-51B, FW190A, Fiat G55, La-5, F6F And even the Gloster Meteor were all available in 1943, and have proven combat records.

The Martin Baker MB5 was the best fighter of World War 2, irrespective of the minor detail that it never shot down another enemy aircraft.
One could also make the argument that the Me-109 was the best of WWII fighter because it shot down more enemy aircraft than any other.
 
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