Post your higher ATA in Anton

[grafspee]

This is what i could get.

Can we call it 1.58ATA ?

Edited January 5, 2022 by grafspee

[LeCuvier]

You must be kidding! The highest I can get is about 1.42. Did you fill her up with nitroglycerin?

[grafspee]

I climb to alt where second gear kick in and then i descend and ATA is rising up above 1.42, as far as i am concern it is just straight bug, Anton broken beyond limits. 

ED it is time to fix stuff, it is about time to do it.

Edited January 5, 2022 by grafspee

[LeCuvier]

I tried exactly what you describe, but the pressure didn't rise significantly above 1.42. Can you reproduce this every time?

[grafspee]

Oh yes i can, max ATA depends on how much RAM do you have.

 

[Katj]

Are you able to sustain that boost or will it drop with speed?

[grafspee]

Yes you can sustain it in level flight, you cant sustain this very high ATA it will drop when speed drops but in level flight you are able to sustain high ATA for very long time, just not as high as in dive

Edited January 6, 2022 by grafspee

[LeCuvier]

OK I got beyond 1.6 ata starting the dive from above 6000 m, but the Ram effect only kicks in when I get above 700 km/h and then the pressure rises abruptly to above 1.65 ata. The manoeuvre does not feel comfortable! And I would have expected the engine to die. When I tried something similar with the jug, the boost pressure went up to 68 PSI (4.5 ata) and the engine overheated.

[grafspee]

2 hours ago, LeCuvier said:

OK I got beyond 1.6 ata starting the dive from above 6000 m, but the Ram effect only kicks in when I get above 700 km/h and then the pressure rises abruptly to above 1.65 ata. The manoeuvre does not feel comfortable! And I would have expected the engine to die. When I tried something similar with the jug, the boost pressure went up to 68 PSI (4.5 ata) and the engine overheated.

It is not psi in P-47 but inHg 30" = 1.1ATA. P-47 does not have boost regulator, so pilot have to watch MP in dives. Fw190 does have and i don't know why it allow to boost go beyond max limit.

[LeCuvier]

2 hours ago, grafspee said:

It is not psi in P-47 but inHg 30" = 1.1ATA. P-47 does not have boost regulator, so pilot have to watch MP in dives. Fw190 does have and i don't know why it allow to boost go beyond max limit.

Thanks! I was wondering how they could get 60 PSI .
Now this is clearly a bug then and it needs to be formally reported. With a track of course!

PS: the Kurfürst boosts up to nearly 2 ata in this nearly wing-breaking scenario. Is that realistic?

Edited January 6, 2022 by LeCuvier

[amazingme]

You mean the Dora.. Yes, it used Jumo 213 engine with Beru F280 E43 sparkplugs to cope with the 1.98ATA.

[grafspee]

Yeah Dora has different engine, and it revs to 3250rpm and this alone allow for higher boost.

You can check it but Dora boost up to around 2.1 ATA even at lower speed, so max ATA is not affected by air speed like in Anton.

[LeCuvier]

7 hours ago, amazingme said:

You mean the Dora.. Yes, it used Jumo 213 engine with Beru F280 E43 sparkplugs to cope with the 1.98ATA.

Yes, sorry it was late (lousy excuse!)

[ButcherBiird]

Except this really shouldn't be a bug. IRL the anton did achieve boost pressures of 1,58 and 1,65 ata. Checkout this thread for more info as those boost pressures were nowhere near enough to destroy the BMW801. It was running those pressures for to long that imposed a thermal limit as overheating is a no no but it says in the official flight manual 1,58 and 1,65 could both be maintained for 10 minutes at a time at which time the engine needed to cool then you could do it again.  

[grafspee]

Agree, but our Anton is limited to 1.42ATA and boost regulator somehow fails to maintain 1.42.

[EnvyC]

On 1/6/2022 at 9:21 AM, grafspee said:

I climb to alt where second gear kick in and then i descend and ATA is rising up above 1.42, as far as i am concern it is just straight bug, Anton broken beyond limits. 

ED it is time to fix stuff, it is about time to do it.

 

The alt limit for the switch back to the first supercharger gear is *lower* in descent than it is during ascent, it was a design choice by BMW to make sure pilots had maximum available ata during an emergency dive.

Greg speaks about it in one of his BMW801 videos.

[grafspee]

2 hours ago, EnvyC said:

The alt limit for the switch back to the first supercharger gear is *lower* in descent than it is during ascent, it was a design choice by BMW to make sure pilots had maximum available ata during an emergency dive.

Greg speaks about it in one of his BMW801 videos.

It is in every plane that switch to lower gear happens on lower alt, my issue is why i can boost beyond 1.42 ATA and this does not explain why i can boost over 1.6ATA

And there is second thing, why supercharacter speed don't change when ATA starts to drop, why supercharger high gear goes in when ATA is low i can't remember exactly but change happens after ATA drops to 1.1. Reason is the power output of the engine, supercharger speed changes when power output for low and high gear equals, so when you switch engine running on low blower with 1.3ATA boost in to high blower you will loose power.

For example V-1650-7 peak power for low blower is 1720hp and for high 1490hp it it obvious that you have to wait until power drops to 1400 on low blower to have any benefit switching in to high blower.

I think they did that to not over cool engine in high speed dive, which already had very efficient cooling, but higher ATA does not mean higher power when comparing engine on different supercharger speeds.

 

Edited February 6, 2022 by grafspee

[EnvyC]

Oh I agree with the 1.6 thing, seems weird.

[Slice313]

Another Anton bug for the collection. Happened to me as well.