Is this true?

[SFRT - Frenchy]

4. Notes on the Messerschmitt Bf-109 E-7/Z Fighter

The Bf-109 E-7/Z was a version with the DB 601N engine equipped with a high-altitude nitrous oxide injection system (GM-1). The system was prohibited to use under 6500 meters because of imminent damage to the engine, but in case of emergency it could provide extra 80 km/h of speed for a short period of time above 5.0 km.
In this version (1.2) the GM-1 boost system is activated when you engage WEP mode on the engine (W key by default). Avoid engaging the system on altitudes below 6500 m.
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What type of stuff u guys want to have mounted on the D9 or TA152 or 109-G10? Would it be supposed to have the same limitation?

[Wotan]

gm1 was used above 6500 meters under that they used mw-50

6500 meters is just 21325.4 ft.

Bombers flew from 20-28000ft. Enemy fighters higher. Above 20000ft most german planes lose performance especially compared to the jug, p51 and spit.

fyi the db601n is the same eng as the 110c in ah. also there were 1094-4s with the db601n.

[Wilbus]

The altitude for use of MW50 and GM1 was different depending on plane. The GM1 was only used ABOVE the engines maximum boost, for 190 A using BMW 801 D engines, this altitude was about 18-22k or so.

For the Ta152 this altitude was 35k (litte more). Bellow 35k MW50 was used. in AH MW50 is modelled on the Ta152 but GM1 is not or if it is, it is drasticly undermodelled (it added 410 HP with an average consumption of 100 g/s, it could also be run on 150 g/s which would give it even more HP, and on 60 g/s which would give less, this could be altered in flight.)

So GM1 alt depends on what engine the plane uses. Never heard of a 109 E that used it however. Never heard of a 109 E7/Z either, so might very well be true.

Limititation would depend on size of GM1 and size of MW50 tank aswell as rate of consumption. On 100 g/s the Ta152 had enough for little more then 17 minutes.

The Dora should have MW50, not sure if it does in AH, it's not the fastest possible Dora though we know that, just as many other planes in AH are not the fastest possible of their kind.

109 G10 used MW50 I think, not sure if it is modelled in AH.

[Pongo]

In Il2, where that quote is from. The Emils engine is wrecked almost imediatly if you engage below that alt.

[HoHun]

Hi Frenchy,

>Is this true?

Yes.

The Me 109E-7/Z used an early form of N2O injection that relied on the nitrous oxide being stored as a pressurized liquid in two separate steel pressure vessels of 7 L content each in the aft fuselage. The Friedrich series had a GM-1 version, too - the Me 109F-4/Z.

Later implementations of the GM-1 system (probably starting with the Gustav series) had a large single pressure vessel from light alloy behind the cockpit in which nitrous oxide was stored as a cooled liquid at -90 °C.

This proved to be a better method of storage and yielded even more power due to the charge-cooling effect of the N2O evaporation.

Though the standard Me 109 and Fw 190 Rüstsätze allowed only a fixed rate of injection, in bomber and reconnaissance aircraft, nitrous oxide could usually be injected at three specific rates which were determined by the size of the two injection jets. Rate 1 was achieved by using the smaller jet, rate 2 by the larger jet, and rate 3 by using both jets simultaneously.

The record altitude achieved by a Ju 86R with Jumo 207B Diesel engines and GM-1 injection was 15 km (49000 ft). At 10 km altitude, the Ju 88T reconnaissance version boosted their BMW801D engines from 880 HP normal to 1430 HP with the help of GM-1. The Me 109G-1/R2 achieved a ceiling of 13.8 km (45300 ft).

Unlike MW50, GM-1 could be used for unlimited periods of time (until GM-1 ran out :-) The Me 109 had, depending on the Rüstsatz, 34 to 135 kg of N2O which was injected at 100 g/s.  The light load probably was used in the early Me 109E-7/Z and sufficed for 5 to 6 minutes, while the full 135 kg load lasted for more than 20 min.

(Tests were conducted with liquid oxygen as well, which apparently could be used with normal GM-1 gear, but these resulted in excessive combustion temperatures and serious detonation problems.)

>What type of stuff u guys want to have mounted on the D9 or TA152 or 109-G10? Would it be supposed to have the same limitation?

The altitude limitation was normal for all Luftwaffe nitrous oxide injection systems. In fact, the higher you got, the greater the contribution of GM-1 to the total power became as whatever the altitude, a certain rate of injection resulted in a fixed HP gain.

The Fw 190D-9 and the Me 109G-10 relied on MW50, though, which was mostly effective below full pressure height.

The 152H-1 had both MW50 and GM-1 to benefit from a power increase at any altitude.

Regards,

Henning (HoHun)

[SFRT - Frenchy]

Excellent, tyvm, I do have a better understanding now.