questions about the 190 a5 versus a8

[Pongo]

 

Originally posted by RAM:

 

ein?...dont understand what you mean pongo...

anyway I did another post   so, I'll see it by first hand isnt it?  

In your first post you said you rarely fly above 15k.
several posts later you upped it to 17k
I was pointing out that at that rate you should start worring about 20k in another post or so.

[RAM]

ahh,yes

that is because I did a couple of P51 sorties yesterday night   climbed up to 17K on one sortie and to 20K in another  

In 190 I rarely go over 15K (main reason:its boring and I can defend myself against bouncing cons   ), in any other plane (including 109G10),its very very unusual to see me over 17-18K  

well I once went up to 25K last week...let autopilot on in a G10 and went AFK...when I returned the plane was at 25K  




[This message has been edited by RAM (edited 11-03-2000).]

[LJK_Reschke]

 

Originally posted by Zigrat:
no one knows the answer? especially the second graph. Why is the a8's engine losing power when the a5s is gaining it? (between 8 and 17k)

why is the a8s climb not improved from 0-2k where it has quite a bit more power available than the a5?

why under WEP at 4000 feet is there a more than 1000 FPM difference in climbrate?When you look at the speed charts for this same point, the a5 and the a8 have (approx) teh same speed at this point.

The only curve that behaves like it should to me is the first. It shows that the a8 has a 3% higher CD,0 than the a5 (to be expected since of bumps for mg131 etcera).

Then taking this data for CD,0 and looking at power for max speed at sea level you can calculate that 6% more power is being generated by the a8's engine at sea level, military power (withouyt wep the a5 and the a8 have equal speeds on the deck)

so then look at the climb rate charts under military. a 600 FPM difference when both aircraft have the same bhp/(CD,0*A).

Doesn't make sense to me.

Zigrat,

Just a thought but if I remember right wasn't the A-8 more of a Jagdbomber variant and widely used in the Sturmstaffels for bomber interception?  Also the A-8 had an increase in armor plating along the leading edge of the wings for the Sturmstaffel role of making a ramming pass on the bomber they were attacking.  

How effective this ramming was I do not know but I do believe my first statement here on this is correct.  If not I hope someone would correct me then.

------------------
Maj. Reschke
Kommandeur Jagdbomber,
StaffelKapitaen I-31 LJK
www.luftjagerkorps.com

[funked]

Reschke:
 

Also the A-8 had an increase in armor plating along the leading edge of the wings for the Sturmstaffel role of making a ramming pass on the bomber they were attacking.

The only A-8's with armor in the wings were those with MK 108 mounted.  The armor was there to protect the containers for the HE ammo.

Zigrat:
As I explained in the arena, the performance of these two planes in AH appears to be based on two sets of flight test data - the A-5 from USAAF data and the A-8 from Focke Wulf data.  I'm guessing that the Focke Wulf data was more conservative.

If you are asking for Pyro to ignore the flight test data and use engineering information to project what the planes "should" do, be careful what you ask for.  Some planes would probably end up a lot faster and some would probably end up a lot slower.  I say stick with the most complete existing flight test data, for better or worse.

[This message has been edited by funked (edited 11-07-2000).]

[Vermillion]

Too true Funked.

If you think the N1K2 is a terror now, imagine it if its engine was producing a true 1990 hp, running on 100 octane fuel (ie what it "theoretically" should).

I figure it for a 410mph or so fighter, and down low at SL it would be much faster than it is now.

------------------
Vermillion
**MOL**, Men of Leisure

[Zigrat]

but hte data doesn't make sense

look at the firdst graph. that makes sense. the 190 a8 is slightly slower than teh 190 a5 at all except the lowest altitudes because of 2 factors

1) the drag coefficient of a8 is slightly higher than a5

2) the extra power of a8 at low alt cancells this fact out and htey have equal speed on the deck, but at all other altitudes their power curves appear normal

Now look at the second curve. same power settings, but for climb.

2 thinks smell wrong about this :

1) The a8 does not get any climb advantage from its extra power available in that below 3k alt range

2)the a8 steaduly loses power from 7 - 17 k , while the a5 gains power in this regime.

From what i understand of the engines in the a5 and the a8 they were the same other than a special boost system the a8 had for emergency power at extremely low altitude.

[funked]

Go look on my website http://www.raf303.org/funked/stuff.htm
Check out the actual data points for the Fw 190G-3.  The curves on the chart are drawn to fit the points, not the other way around.  If you look at the actual data points they are quite ugly - if they did error bars they would be quite large.

Then look at the Fw 190A-8 stuff.  Notice how the German stuff has nice smooth curvature.  Almost as if... they calculated it instead of actually measuring it.  Or they measured a few points and adjusted their calculations to fit.

This is what happens when you get two sets of  curves prepared with two different methods from two sets of data that taken a year apart in two different countries by two different sets of pilots and technicians on two different aircraft which possibly came out of two different factories.

That's why the data doesn't make sense.

And if you look at different sets of data for a lot of WW2 aircraft you will see this same trend.  Even when testing aircraft of the exact same specification they got different results.

[eye]

I used to do some drag raceing with my mustang.

On a hot day you would run slower.

How much moisture was in the air affected how fast you could go too.

How can you compare 2 different planes if they were tested on different days.

You would be able to tune any motor for the particular days atmosphere + temp.

You could get a huge performance increase too depending on the tune.
A decrease too.

This is something ive wondered about alot reading guys posts on plane performance.

Compareing Testing on two different days could be as big a mistake as useing different countries data.

Also if they are useing a equation to correct for the different days air temp moisture etc How do you know the us or the russians did the same.

What about the mechanics too? A good one might hot rod your motor. Raise your compression Different spark plugs or exaust manifolds. Mix and match stuff to get a faster plane.

Some guys pulled out some of the armor or guns too.

How do you know a captured plane  would run as fast as one thats well maintained by a excellent tuner?

There's alot of leway in all this aircraft data that we all have and read.

Btw i cant believe the a8 is as bad as it is.
Why would the germans make a plane that is such a regresive step?

EYE

[Zigrat]

Exactly EYE,

If the 190a8 was as much of a sytep down from the a5 as itwas in AH, they would not have produced it! This in itself is almost sufficient reason to show that the a8 in AH is incorrect.

[Zigrat]

you have a MUSTANG??????

you must be joking right?

[Badboy]

 

Originally posted by funked:
Go look on my website http://www.raf303.org/funked/stuff.htm
Check out the actual data points for the Fw 190G-3.

I tried to check out the USAAF Flight Test Data for Fw 190G-3 but the links to the pages of the report don't seem to be working?

Is that information still available?

Badboy

[Badboy]

I spoke too soon, works fine now.

Badboy

[juzz]

I think he meant Ford, not North American Zigrat...

As for the A-8: It followed in the same sort of development as other planes(eg: Spitfire, Me 109), ie: more guns, more armour -> more weight. But in this case the one thing it didn't get was more power, so performance obviously went down the tubes.

[SageFIN]

juzz, the problem here is that the A8 did get more power compared to the previous models of 190 though it only matters down low. The germans managed to increase the compression ratio and thus got some extra boost out of the same engine but was only effective very low.

Perhaps my explanation was a little vague. Ask Funked for more information. I'm sure he has some  

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---
SageFIN

"The wolves are gathering, the stars are shifting...
come, join us in the hunt!"
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[funked]

Yeah the G-3 website wasn't working yesterday.  It's free webspace, and ya get whatcha pay for.