Originally Posted by BlackBerry
1) German tried MW50 on BMW801 but finally gave up. It's said that MW50 is harmful to BMW801's piston. 1945 version Dora's Jumo213A(liquid cooled) was equipped with MW50. However, 20000ft(6000m) is probably above 190's FTH, so there is little benifit from WEP.
ah, okay. I read wiki they had used a version of a-4. But if it didn't work, it's not relevant. Lets leave out the dora/jumo too. Actually, iirc, dora was modified to handle mw50 at higher alts than 109 @ 6000 meters. Definitely the Ta 152 was. And then there was the gm1 (forgot the name). Actually, I fly UP 3.0 RC4 which uses 4.10 as base. Haven't tried 4.11 yet. But I checked all the fw190As in ultrapack, and none have mw50. some have the added fuel injection. so there you go.
At "A" point, if fw190 uses 1050rpm propeller, tip rotating speed is 165m/s, TAS is 126m/s, Mach number=207/310=0.67. Quite below 0.9mach. But I'd to say the propeller's has a certain optimised rpm, if you use full 100% throttle while reducing propeller's rpm incorrectly, you will lose efficiency. Your propeller probably couldn't absorb engine's output.
yea, I was thinking like a range of acceptable efficiency (going back to the .7-.9 range for the p47 prop). so your running auto pitch at about 400 kph about to start your dive. then you go manual mode using the vdm 3 way switch. So you quickly run up the rpms (toggle the switch) and atas ~1.4 to get the tip speed at the high end of the mach range. then put the load on by toggling the three way switch to the other position and slowly back off the atas as your in your dive. your accelerating, tas is going up and prop efficiency is going down. When your rpms are at 2100 on the indicator and your at the low end of the mach range for the prop, you go to auto prop pitch and your atas are running ~1.0 or so and your prop self adjusts to the TAS at that moment . Assuming they engineered out the rate of change on the blade angle so that you do not lose power in the transition. I think its like 3 degrees every one second or something like that. I forgot. All this happens very fast. like in a few seconds. I coded a 3 way switch in glovepie to do this, btw.
2) C point is above fw190's max allowable diving limit?
yes, but getting close. your tas is still increasing. its time to make a decision
and there is only one thing to do. p47 has a lot more headroom @ 1000 kph.
3)I don't know how long does it take for p47 turbo to spool up. I guess it's several seconds?
yes. i think so. I was thinking mw50 is instant satisfaction verses turbo lag. but since mw50 not on a4. but dora, yes. So we can ask DT if turbo lag is modeled correctly.
4)Last but not least, Do you have the information of Dora's 41276.16 V propeller? The size of it, the reduction ratio etc. As we all known before 4.11m, Dora flys so fast.
sorry,I'd have to google. I wasn't really intending to change discussion to dora. It's a different plane. jumo was way better engine. much higher rpms capability. I guess that is germans partial answer to opponent with bigger prop size. in ultrapack doras, there is a torque limiter. So you can crank a load from say 3700 rpm to 3000 rpm with mw50 on max ata. then you have to switch it off/cut ata and you can crank the load from 3000rpm to say 2700 rpm.
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