U2 = Recce - That pic of Barkhorn's G-5 you snagged and cropped from Falcon's 109 site isn't equipped with GM-1.
GM-1 wasn't standard and its usefulness was very marginal. It could only be used some 2000m above FTH. It greatly increased fuel consumption as well.
It wasn't their to provide combat power at high altitude for dogfighting but to allow for 'escape' - used mostly by Recce aircraft who were either lightly armed or unarmed all together.
HoHun in an old post on this forum gave the following reply for those interested in its operation:
GM-1 was the German WW2 code-name for N2O (nitrous oxide, or laughing gas).
N2O can be added to the fuel-air mixture of an internal combustion engine. In the compression cycle, it's broken up into its components, releasing oxygen that can be used for combustion.
As the challenge of high-altitude flight mainly consists of getting enough oxygen into the cylinder to maintain adequate power - which due to the decreasing air density becomes more and more difficult at altitude - N2O equates to extra power.
In fact, N2O was injected into the supercharger in liquid form through small jets, and each jet gave a constant power boost when employed. Depending on the type, you might have a 120 HP jet and a 240 HP jet, which of course added 360 HP when used in combination.
That's the resason N2O was available in steps - you couldn't add 360 HP to an engine that was already running at close to full power, or the resulting forces would destroy vital parts of the engine.
This is the main reason N2O was preferred over pure oxygen, which could be (and experimentall, was) used for the same purpose - it just gave too much power.
The nitrogen share of the nitrous oxide has a benefit, too, since it absorbs some energy on being broken up in the cylinder, controlling the detonation and allowing higher pressure.
Since N2O is injected into the supercharger as a liquid, it also gives a charge cooling effect on evaporation (cooler air means more oxygen in the same volume).
Initially, N2O was stored under high pressure to keep it liquid (laughing gas, after all, is a gas under standard conditions), but that meant the N2O vessels blew up like a bomb on being hit, so from 1941/42 on it was stored at very low temperature in an insulated tank that kept the content at less than -90 °C for as long as the sortie lasted.
(It was used by bombers like the Ju 88 and by reconnaissance planes like the Ju 86 as well, so that could be quite a long time. For fighters at readiness on the ground in the hot summer sun, though, the insulation would not have sufficed and the N2O would have begun to boil out through the safety valve after a while.)
For comparison: 0.1 kg/s of N2O injection gave extra 300 - 400 HP, virtually out of nothing.
The only drawbacks were the weight of the system (which also included compressed air bottles to force the N2O out of the insulated tank), and - more importantly - the high rate of consumption. If 0.1 kg/s gave 350 HP, that made for a specific fuel consumption of 1000 g/HPh, which compares very unfavourably to the DB601A's normal 220 g/HPh at high power :-)
So, N2O was bad for range, but great for high-altitude power.
Oh, by the way, someone mentioned that N2O was to be used for short bursts only. According to what I have read, it could be used as long as it was available and in fact short bursts were to be avoided as filling and emptying the N2O lines took some time and created some engine management difficulties.
Regards,
Henning (HoHun)
I was a big advocate for the addition of the G-14 to AH. It's my favorite 109 of all times next to the G-6. I had asked that when HTC re-did the old G-10, and re-designated it as a K-4, that they keep a 'G-10' with a corrected FM (could use same model as K-4 but different skin - 428mph or so at FTH). This would have finished out the Bf 109 series. A 'G-10' with new FM could have been used as a substitute for either the G-14/AS, or more rare G-6/AS. This would have given AH a Bf 109 that could be used effectively in the 8th AF CT - higher FTH then the G-14 below current K-4 performance. They decided not to bother.
As is the G-14 has a FTH of just 5000m (16400ft). Above that it will just be marginally faster then the G-6. As such a Bf 109 pilot will be basically be flying the same 'aircraft' (based on performance) from Feb '43 until Oct '44. The G-6/AS entered service in May '44 and the G-14/AS June/July '44.
During the Fw 190 re-model we all asked that the Fw 190A-6 be added - same FM as the A-5 could have been used but instead of 2 x MG151/2cm and 2 x 2cm MGFF/M (60 round drums even though the A-5 could carry 90 rounds drum - another long time request that has gotten no support) the A-6 carried 4 x MG151/2cm - considerably better lethality against bombers.
Other things like the addition of the P-47N over the P47C means very little 'happy times' (term borrowed from the Kriegsmarine - where the LW enjoyed numbers and/or a performance edge) for the LW in an 8th ToD. This is irregardless of 30k dogfighting or not.
HT has said not all missions will result in a human being killed - insinuating that some missions maybe easier then others. That's not to say the CT won't be fun or competitive - it just means as a LW flier you will be well behind the performance curve of the Ami Fighters. Which makes flying smart and the use of proper tactics the key. This may make for a real sense of immersion but its yet to be seen how it plays out in a 'game' given AH's player base.
