MW-50/GM-1 explained! For those not sure:)

[SIFTER]

For those that don't know:"Water-methanol injection (code-named MW-50 depending upon whether 30 or 50 percent methanol was used in the mixture) improved performance at altitudes BELOW the rated altitude of the engine.(rated Altitude-The altitude at which the supercharger was allowed to deliver its full pressure to the induction manifold. Above the rated altitude, the power delivered by the supercharged piston engine gradually decreases)The Water did the work; the methanol was there merely to prevent the water freezing at low temperatures.The mixture was injected into the eye of the supercharger and acted as an anti-detonant, cooling the charge and enabling higher compression ratios to be used.
GM-1>>> Nitrous oxide(laughing gas) injection was used to improve the performance ABOVE the rated altitude of the engine. The nitrous oxide was stored at minus 88 degrees centigrade in its liquid form in heavily lagged containers. It was injected into the supercharger inlet, where it provided additional oxygen for combustion, acted as an anti-detonant and cooled the charge; its effect was to enable the engine to continue to deliver high power at greater altitudes than would otherwise have been the case." The systems did add mucho weight:"The MW-50 installation for the G-14 weighed about 300 pounds, complete with 26 gallons of water-methanol.The GM-1 installation fitted to some G models weighed 670 pounds, with 16 gallons of nitrous oxide." The Germans had to do the best they could using fuels of 100 octane rating and lower. The allies had fuels of 100/130 octane. When used on very few A-8's..."it can be used at an altitude above 26,250 ft and gives a speed increase of about 36mph at climb and combat power." Wouldn't that make the A-8 a screamer? They rarely used it on the A-8. They preferred to use the extra fuel tank.          Berserkr
 

[funked]

Here are Focke Wulf's performance data for Fw 190A-8:  http://www.raf303.org/funked/a-8manual/

Note the page for GM-1 performance showing increased speed and climb rate over 8km altitude.

[funked]

This would be a nice loadout option - aft fuel tank replaced by GM-1 tank.

[wells]

I always wondered how much GM-1 was carried in the 109.  Where'd that info come from??  Is that 16 Imp gallons or US gallons?

Thanks Sifter!

[This message has been edited by wells (edited 05-29-2000).]

[juzz]

I think MW 50 would still provide a power increase even over rated altitude - while the supercharger can't be overboosted anymore, the water/methanol is still cooling the intake air.

Anyone got info on American water/methanol injection and power vs altitude?

It would be nice to have the option of MW 50/GM-1 as "loadouts" for German planes that could have it. Eg: Fw 190A-8, choice of extra fuel or GM-1. For historical scenarios where appropriate they could be disabled.

[Skorpyon]

Juzz, at first glance, you would think so, but actually not.  The nitrous serves two purposes.  First, as an antidetonant, cooling the air fuel mixture similar to the water/methanol mix.  But at higher alts the nitrous, which has a high oxygen content of its own, replaces the oxygen that is absent at the higher alts.  The "thinner" air at high alt decreases the ability of the air-fuel mixture to combust efficiently, thus the decrease in engine performance past a certain alt. The nitrous fixes the problem.  The supercharger shoves more air/fuel mixture in to the engine than a normally aspirated engine, and the nitrous makes it a more oxygen-rich mixture.

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Skorpyon
I/JG2 ~Richthofen~
"Feel the Sting......"

[-lazs-]

U.S. wep systems also work on water/alky.  The U.S. superchargers were superior to early LW units and could be boosted to very high levels.   Corsairs could use two settings with wep, one with mp at 60 for 2250hp and one at 65 mp for over 2300 hp.  I believe that they were set at the factory at 60 but field mechanics were, after all, American kids with Hot Rods at home.
lazs

[funked]

Cool Lazs, sounds just like the "boost override system" described in the A-8 manual, or that P-39D in the Zero book that was pulling 70(!!!) inches.

[This message has been edited by funked (edited 05-30-2000).]

[juzz]

Talking overboost and water injection - RR had a Merlin II with water injection putting out 2150hp @ +25lbs boost in early 1938. Although, the engine only lasted 15 minutes at full throttle.  

[-lazs-]

Yep... I think every plane had "field mods".  Allways hard to figure whjat we "should" have..... Recomended/majority or possible?

Oh... A seies C  P47 R2800 turbosupercharged engine was boosted to 3000 hp and run full bore on a test stand until it used up 300 gallons of fuel.
lazs