Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Zigrat on November 02, 2000, 08:43:00 PM
-
i plotted their data on the same axis..
(http://www.iit.edu/~buonmic/milspeeds.gif)
(http://www.iit.edu/~buonmic/milclimb.gif)
(http://www.iit.edu/~buonmic/wepspeeds.gif)
(http://www.iit.edu/~buonmic/wepclimb.gif)
just doesnt seem to be that a 700 pound increase in take off weight (~8.5%) should cause a 25% reduction in climb speed.
1) Below 2k feet where the a8 gets the extra bootst, it appears to help with the top speed, but not climb rate.
2)In the 7-17k foot range under military power, the 190 a5's engine gains bhp, but the 190 a8s loses it.
3) The 190 a8's engine starts losing power at 1k feet lower than the 190 a5.
4) Under wep cclimb, the a8 starts losing climb rate at 2k, the 190 a5 at 4k. I thought the 190a8 had improved extreme low alt performance?
Using a 200 ft Reference area i calculated the CD,0 of the 190 a5 to be .048, seems pretty in line with my expectations. But the wierd gyrations in the power curve seem very strange for a airplane mounting close to the same engine... between 1942 and 1944 did the germans really decide to design up a worse revision of their engine?
[This message has been edited by Zigrat (edited 11-02-2000).]
-
Whats your question?
-
So?
Apart of a marked lack of top speed for the Fw190A5 (wich I think that everyone had noticed already) at 20K I dont see anything too serious...
BTW I dont mind about 20K topseed because I rarely go over 15K
(http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
-
A-8 is still a better plane, IMO.
Guns, dive and deck speed make it better than the A-5.
-
But acceleration and maneouverability makes A5 be able to survive most dangerous situations while A8 can't (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
-
...and speed.
190a5 should be at 15mph faster than A-8 (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
-
Originally posted by Fishu:
...and speed.
190a5 should be at 15mph faster than A-8 (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
At 20K more or less,yes...
But I dont mind...you'll rarely see me over 17K (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
-
"
BTW I dont mind about 20K topseed because I rarely go over 15K
At 20K more or less,yes...
But I dont mind...you'll rarely see me over 17K
"
One more post and you will be at 20k..
more or less
-
(http://bbs.hitechcreations.com/smf/Smileys/default/confused.gif)
ein?...dont understand what you mean pongo...
anyway I did another post (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif) so, I'll see it by first hand isnt it? (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
-
Originally posted by RAM:
At 20K more or less,yes...
But I dont mind...you'll rarely see me over 17K (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Chart clearly shows to me that 190A-5 leads by about 15mph in all altitudes (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Funny thing though.. I prefer A-8 over A-5
-
I don't know if you guys realise that A5 was based on the very successful germna fighter Fw 190A4. The test pilot of Fw 190A4 said that he could make it even better and he did !!!
So, yet again it proves that all planes are direct desendends of Fw 190 !!! (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
------------------
Bartlomiej Rajewski
aka. Wing Commander fd-ski
Northolt Wing
1st Polish Fighter Wing
303 (Polish) Squadron "Kosciuszko" RAF
308 (Polish) Squadron "City of Cracow" RAF
315 (Polish) Squadron "City of Deblin" RAF
Turning 109s and 190s into scrap metal since 1998
Northolt Wing Headquarters (http://www.raf303.org/northolt/)
-
...and speed.
190a5 should be at 15mph faster than A-8
Sorry Fishu, that's simply incorrect. There is no data to support such a claim.
-
Originally posted by funked:
Sorry Fishu, that's simply incorrect. There is no data to support such a claim.
I have seen data of A-5 having about 15mph speed advantage over A-8.
(didn't we discuss about this couple months ago and you agreed?)
-
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.
-
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.
who cares-- grab a USAAC aircraft and go (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
-
Originally posted by RAM:
(http://bbs.hitechcreations.com/smf/Smileys/default/confused.gif)
ein?...dont understand what you mean pongo...
anyway I did another post (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif) so, I'll see it by first hand isnt it? (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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.
-
ahh,yes
that is because I did a couple of P51 sorties yesterday night (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif) climbed up to 17K on one sortie and to 20K in another (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
In 190 I rarely go over 15K (main reason:its boring and I can defend myself against bouncing cons (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif) ), in any other plane (including 109G10),its very very unusual to see me over 17-18K (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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 (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
[This message has been edited by RAM (edited 11-03-2000).]
-
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
-
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).]
-
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
-
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.
-
Go look on my website http://www.raf303.org/funked/stuff.htm (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.
-
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
-
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.
-
you have a MUSTANG??????
you must be joking right?
-
Originally posted by funked:
Go look on my website http://www.raf303.org/funked/stuff.htm (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
-
I spoke too soon, works fine now.
Badboy
-
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.
-
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 (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
------------------
---
SageFIN
"The wolves are gathering, the stars are shifting...
come, join us in the hunt!"
---
-
Yeah the G-3 website wasn't working yesterday. It's free webspace, and ya get whatcha pay for. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
-
Only about +150HP at emergency power. And that shows in the charts -> A-8 is faster low and even climbs better for a little bit... "more power" would have been an increase to 2,000HP or more(eg: BMW 801TS).
-
ok, other question.
in every book i've got about the 190, it had
"excellent dive and climb!!! abilities.
ok, dive is ok, but in every sim i know the
"great climb" ability is not there. it's a brick.
like the 109, the construcorsof the 190 swapped turn ability for climb and dive ability.
it's not a whine, only a copy of the advantages the 190 had. and one of it was the
climbing ability.
comments pls
(have no book saying 190 climbed bad..)
-
Sage the A-8 got more power at low altitude via a modification that allowed the pilot to override the automatic boost control and overboost the aircraft at low altitudes, with a penalty in oil temperature and engine life.
There was also a supplemental fuel injection system which injected fuel directly into the supercharger inlet, but the handbook for the aircraft indicates this was phased out, and that the boost override gave similar performance.
[This message has been edited by funked (edited 11-13-2000).]
-
I'd say near 4000fpm is fairly good for an early 1942 fighter...
-
Habicht,
mostly they mean zoom climb ability.
Macchi
-
Yep Juzz the AH Fw 190A-5 outclimbs most of the 1941-2 Allied birds.
[This message has been edited by funked (edited 11-14-2000).]
-
I would like to have 190-a6
ability for 4 20mm mausers, but not the crappy performance of a8.
-
bump
-
and no i dont want hitech to make up data for 190a8
i want him to do same thing for how he got f4u-1c flight model, he took f4u-1d and subtraced a few hundred pounds
in this case, take 190-a5 add the appropriate weight and power boost at low alt.
tit-for-tat
-
Zigrat, as I posted in other thread, we have an A8 with the extra 118 liters tank (aux) desingned for boost mixtures (MW 50). BMW 801D was, by design, able to accept MW 50 mixture and nitrous oxide for GM-1 devices.
We have all the installations, but we dont have the mixture (MW50). So, each time you fill up your tanks in A8, you are, for the same %, adding more weight to A8 than to A5, because our boost liquid tank is being used as a normal fuel tank, you'll have a heavier A8 without the extra 350 hp courtesy by the anti-detonation methanol/water mix.
As a matter of fact, range was not a primary key for the A8 role in the war. The primary key was top speed at medium and hi alts for bomber interceptions as much as climb rate. If that auxiliary tank was present in all 190A8s (with its extra weight, pipes, control system, etc) and IMO this is an evidence of the usage of MW50. If not MW50, then GM-1 (or even both), but something to justify the substitution of A5 by A8.
With the actual performances, A5 is way better suited for buff interception than A8. I can hardly catch a B17 at 20k with my A8 (wep on), and this was supposed to be its normal duty during WWII.
-
Originally posted by funked:
Sage the A-8 got more power at low altitude via a modification that allowed the pilot to override the automatic boost control and overboost the aircraft at low altitudes, with a penalty in oil temperature and engine life.
There was also a supplemental fuel injection system which injected fuel directly into the supercharger inlet, but the handbook for the aircraft indicates this was phased out, and that the boost override gave similar performance.
[This message has been edited by funked (edited 11-13-2000).]
funked, the systems you describe, without any coolant or antidetonation system like MW50, will produce a quick overheat. That means that 190A8 WEP time should be considerably shorter than 190A5.
In our AH case, A5 and A8 have similar WEP duration before overheat.
Anyway, we are talking'n talking about this topic withoput any real idea of what Pyro implemented here.
Cmon Pyro, write a pair of lines spreading some light over us, mortals.
-
Very good point Mandoble.
Also note that the in-game A-5 and A-8 have the same manifold pressure with 100% throttle and with WEP, and that these manifold pressures correspond to the 30 minute and 3 minute power settings for the standard BMW 801. If there is boost override or petrol injection or MW 50 I would expect to see higher pressures on the A-8.
[This message has been edited by funked (edited 01-25-2001).]
-
Zig, why not do this: For the A-5 model, take the A-8 and subtract the appropriate weight and power boost at low alt. It's just as valid as your proposal. I think your waffle marks are showing. (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
-
Originally posted by MANDOBLE:
funked, the systems you describe, without any coolant or antidetonation system like MW50, will produce a quick overheat. That means that 190A8 WEP time should be
not as I understand it. The high octane petrol injection into the air intake acted as antidetonant by itself (According to the info I have posted in this forum several times), so I think that this is correctly modelled.
-
Originally posted by RAM:
not as I understand it. The high octane petrol injection into the air intake acted as antidetonant by itself (According to the info I have posted in this forum several times), so I think that this is correctly modelled.
RAM, can you, please, refer us to the post where you have the proof of petrol injection acting as an antidetonant system? As a side note, the antidetonant effect alone doesn't mean that the engine will not overheat quicker.
-
no need to refer to the post. Here it goes (one more time)
(http://www.airtel.net/hosting/0003d/ebringas/germboost2.gif)
Please note that the description makes it clear that the petrol injection boosting system also acts as coolant,not only as antidetonant.
[This message has been edited by RAM (edited 01-25-2001).]
-
Good post RAM.
Assuming that petrol injection was present only in A8 and posterior version, still cant understand why those supposed extra 140hp advantage on deck over 190A5 are lost at 2-3k.
If petrol injection acts just like MW50, the effects should be noticeable up to 12k or a bit more.