Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Mister Fork on April 06, 2003, 10:12:05 PM
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Aircraft | Sec | Accl[list=1]
- Me 163 | 6.0 | 7.5
- Bf 109G-10 | 24.8 | 1.8
- Spit XIV | 25.1 | 1.8
- Bf 109F-4 | 25.7 | 1.7
- Bf 109G-2 | 26.7 | 1.7
- P-38L | 26.8 | 1.7
- F4U-4 | 27.0 | 1.7
- Bf 109G-6 | 27.5 | 1.6
- Spit IX | 27.7 | 1.6
- Fw 190D-9 | 27.8 | 1.6
- C205 | 28.5 | 1.6
- P-47D-30 | 28.9 | 1.5
- La-7 | 29.0 | 1.5
- Fw 190A-5 | 29.5 | 1.5
- P-51D | 29.9 | 1.5
- Tempest V | 30.2 | 1.5
- P-51B | 30.4 | 1.5
- C202 | 30.6 | 1.5
- Spit V | 30.6 | 1.5
- Yak-9U | 30.7 | 1.5
- Ta-152H | 30.9 | 1.4
- La-5FN | 31.5 | 1.4
- P-47D-25 | 31.5 | 1.4
- F4F-4 | 31.9 | 1.4
- P-47D-11 | 33.7 | 1.3
- Seafire IIC | 34.2 | 1.3
- Fw 190A-8 | 34.6 | 1.3
- NIK2-J | 35.7 | 1.3
- F4U-1D | 35.8 | 1.2
- A6M5b | 36.9 | 1.2
- F6F-5 | 37.1 | 1.2
- Fw 190F-8 | 37.2 | 1.2
- F4U-1C | 37.3 | 1.2
- F4U-1 | 39.0 | 1.1
- Me 262 | 39.3 | 1.1
- Typhoon | 39.7 | 1.1
- Bf 109E-4 | 41.2 | 1.1
- Bf 110G-2 | 41.9 | 1.1
- Mosq VI | 42.1 | 1.1
- Hurr IIC | 42.9 | 1.0
- Bf 110C-4b | 43.3 | 1.0
- Ki-61-I-KAIc | 44.8 | 1.0
- Yak-9T | 45.0 | 1.0
- A6M2 | 45.2 | 1.0
- Spit IA | 47.1 | 0.9
- Hurr Mk 1 | 57.5 | 0.8
- FM2 | 57.8 | 0.8
- Hurr IID | 59.6 | 0.8
- P-40E | 71.6 | 0.6
- P-40B | 73.9 | 0.6
[/list=1]
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And you wonder why you never see a P-40 above 12,000 feet. :D
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Now i know they all dive away at alt.
AND I LIKE HIGH ALTITUDE FIGHTS !!!!
:mad: :mad: :mad:
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Thanks for your efforts Mr.Fork!! Big
!!
...
Man, I always thought that the 190s were fast accelerating planes. Compared with contemporary Spitfires, at both deck and alt, I don't think there's anyway AH 190s can ever be described "it out-accelerates the Spitfires"...
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If possible, it'd be really great if we can see test results of 50%, 75% and 100% fuel.. :) It'd be interesting to see how the list changes again with different fuel load..
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Why the tremendous difference between F4F4 and FM2?
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I ran those two planes through the same test twice GH because I was surprised too. I also retested the 109F4/G2 and the P-38 just to make sure the numbers were correct.
The F4F-4 for it's age halls ass. Who knows why? I doesn't even have WEP compared to the FM2.
Kweassa - I tried that actually - giving a few aircraft more fuel on the top five and reran the tests. The results are not 'much' different - it just takes longer to accelerate. :)
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Originally posted by GRUNHERZ
Why the tremendous difference between F4F4 and FM2?
Maybe the same thing that happened with the Brewster? Too much weight in the "upgrades" and no significant increase in horsepower.
Camo
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Except I believe the FM2 actually weighed a little less than the F4F4 and had more horsepower. I guess it could have something to do with the gearing in the supercharger, but I would think the FM2 would be superior.
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Yep. FM2 was quite a bit lighter and had an increase in hp over the F4F-4.
Wait a minute, why is the FM2 down at the bottom of the list. I'm guessing these aircraft got transposed in the list.
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Or the FM2 and F4F got transposed in the AH look-up tables. Sounds like a good one to ask HTC about.
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I just re-did the FM2 test. Yep, she's a slow beast. 57+ seconds.
Can anyone explain why the FM2 is a slow tard compared to the F4F-4?
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IIRC the FM2 had a much lower rated altitude than the F4F-4.
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according to that the hurri2c is only 1 step slower to accelerate than the mosquito...i always thought that was a very fast medium bomber...weird
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doesnt make much sense though funky, take a look at the climb rate chanrts for the 2 of em. Does the fm2 match its advertised climb rate at that alt?
(T-D)*V=d/dt(1/2mv^2+mgh)
Ps=v/g*dv/dt+dh/dt
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I'm not even going to pretend I understand your equation Zig.
But this much I am pretty sure of.
There are only about 4 variables to consider here.
1. Lift drag- which is the same in both A/C.
2. Parisitic drag- Same in both.
3. Thrust- The FM-2 must have more since it has a superior climb at the same altitude.
4. Weight- The FM-2 is lighter.
The only possible variations are maybe a different prop or rocket launch stubs that could at parasite drag but I can't believe it would be that much different and still outclimb the F4F-4.
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Originally posted by Mister Fork
I just re-did the FM2 test. Yep, she's a slow beast. 57+ seconds.
Can anyone explain why the FM2 is a slow tard compared to the F4F-4?
Maybe the Wildcat just had a more powerfull engine, that explains why the FM2 has a wep and the wildcat hasnt.
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Might have the answer here-
Looks like the engine in the FM2 (Wright Cyclone R-1820-56 with single stage two speed supercharger) put out more power than the Pratt & Whitney R-1830-86 Twin Wasp- up to 10,000 feet.
Above that altitude the P&W was putting out more power- at 18,000 feet it looks like the F4F-4 would have about 1,100 horsepower while the FM-2 would have about 1,000.
Probably explains the difference in acceleration.
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hmm, yes...that could be it!
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look at the climb rates though. fm2 is supposed to climb much faster. from the equation i wrote you see dh/dt (climb rate) is directly proportional to dv/dt (accel)
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Gents, the difference between the F4F-4 and FM-2 is the supercharger.
F4F-4: Two stage, two speed blower.
FM-3: Single stage, two speed blower.
At 18,000 feet, the F4F-4 has 130 more hp available than the FM-2 (1040 vs. 910).
At sea level, the edge goes to the FM-2 with 1,360 vs. 1200 hp.
Superior low alt climb and better maneuverability of the FM-2 can be attributed to greater power and less weight (the FM-2 being coming in about 450 lbs lighter empty).
My regards,
Widewing
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test at 30,000 ft :D
(please):)
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spit5 out accelerates the ta152? is this due to the weight of fuel 25% is on the ta152 ?
The wep on the ta152 is very powerful and on the spit5 its almost useless.I would have thought the ta152 would slaughter an old spit5 at 18k+ heights. The HP difference is huge isnt it? weights huge difference?
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It was kind of shocking to see the Ta152 scoring about only middle of the list, of all the planes, in the low altitude test results.
It is more shocking to see the Ta152 still scoring poorly even in 18k test results....
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I don't think the Ta152's anything worth 20 perks now...
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Initially yes, if the two aircraft , Spit V and the Ta-152, it would seem obvious that the Spit is a faster aircraft AT 18'000 feet.
But at 27'000 ft, the Spit V takes 62 seconds from 175-275 mph, and the Ta-152 only took 37 seconds.
What do my tests show? At low level engagements, you have to be careful how you enage certain aircraft, and how you extend. If you're low and slow and want to extend in your P-51, if you have a La-5 or La-7 on your six, think again about your decision. Knowing top speeds and accleration rates help you better understand your aircraft and your fighting abilities.
There are also some aircraft performing well at ALL altitudes. The Bf 109G10, Spit XIV, F4U-4, and the Dora come to mind. It also shows the Tempest is not an ideal high altitude fighter.
It also shows that higher up, all aircraft perform different than those low down. It also shows there is a different class of planes to use for high altitude fighting. For example, you may want to avoid dog fighting a Bf 109 series higher up than down low unless you feel confident enough to defeat the pilot from the initial merge.
Use the data and try to understand the context it fits with respect to the aircraft you are engaging. Ie. You're in a Spit V at 18-20000 feet and are bounced by Bf 109's. You know that initially they out accelerate, out climb, and have a higher top speed. That has an impact in how you engage these aircraft understanding the disadvantages you may face.
That being said, it's the man, not the machine you have to worry about. But the man, flying his machine, understanding his strengths and weaknesses and those of his opponents makes him a much better fighter pilot.
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I hate to see the spit ouperformes the P-47 and P51...:(
tho the P38 does a good job :)
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Hi Widewing,
>At 18,000 feet, the F4F-4 has 130 more hp available than the FM-2 (1040 vs. 910).
Actually, in military power the R-1800-56 of the FM-2 yields 1000 HP at 17800 ft. Your figure seems to be for continous power.
Additionally, the F4F-4 with 25% fuel weighed in at about 3300 kg compared to the FM-2's 2935 kg.
10% less weight at 5% less power should make the FM-2 the better accelerating aircraft I'd say.
The Me 109E-4 with around 1000 HP at just 2380 kg should pass them both easily.
I'd expect the Me 110C-4/B with 2100 HP at 6140 kg to accelerate slightly better than the F4F-4.
Regards,
Henning (HoHun)
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*removes the oxygen system from his P-40*
Won't be needing this anymore. :rolleyes:
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Mister Fork:
What were the initial and final velocities for your tests for the F4F and FM-2?
Did you use IAS or TAS readings for initial and final velocities?
Tango, XO
412th FS Braunco Mustangs
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Hi DT (hey, I remember you from the 412 ;) )
I used TAS as the indicator
Vo was 175Mph TAS for ALL aircraft*
Vf was 275Mph TAS for ALL aircraft*
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Fork: - former member of the 412th?
Regarding the FM-2 / F4F-4 differences at 18,000 ft vs. near SL.
(1) Already pointed out by Funked and others, the critical alts of the engines between the FM-2 and F4F-4 are different - FM2 being lower vs the F4F-4.
(2) The acceleration tests being analyzed are average acceleration figures from 175mph to 275mph and not instantaneous acceleration figures at a specific velocity.
(3) The velocities being analyzed (175 mph TAS and above) are above velocity for best rate of climb of the a/c. In these conditions the a/c with the higher max level speed (F4F-4) should have better average acceleration because of the effect of parasite drag increasing by square of velocity becoming more pronounced.
Tango, XO
412th FS Braunco Mustangs
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Hi Dtango,
>Already pointed out by Funked and others, the critical alts of the engines between the FM-2 and F4F-4 are different - FM2 being lower vs the F4F-4.
The FM-2 is rated at 1000 HP at 17800 ft, the F4F-4 at 1040 HP at 18400 ft - that's nothing to write home about.
>The velocities being analyzed (175 mph TAS and above) are above velocity for best rate of climb of the a/c.
Actually, best climb speed of the FM-2 is 125 KIAS, which is 196 mph TAS at 18000 ft.
>In these conditions the a/c with the higher max level speed (F4F-4) should have better average acceleration because of the effect of parasite drag increasing by square of velocity becoming more pronounced.
The higher maximum level speed of the F4F should be mainly due to its 40 extra HP, which seems too little to make such a difference at low to medium speeds.
In principle, you have a valid point however - the Me 109 has both the advantage of a much better power-to-weight ratio and and a superior top speed should really out-accelerate both Grummans with ease.
Regards,
Henning (HoHun)
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Originally posted by frank3
I hate to see the spit ouperformes the P-47 and P51...:(
Why not? The Spitfire Mk IX should out accelerate the P-47 and P-51 at those speed ranges at pretty much all altitudes.
You do realize that the Spitfire Mk IX is a high altitude tuned fighter, don't you?
Part of the problem that Mister Fork's tests have is that they are only testing acceleration at low speeds. If you were testing the acceleration of the Spitfire Mk IX, P-51D and P-47D-30 from 350 to 410 at 25,000ft the Spitfire IX would get toasted because it is at the top end of its speed whereas the P-51 and P-47 still have a ways to go. Add in the Ta152H-1 and Spitfire Mk XIV and the P-47D-30 and P-51D get beat because those two aircraft have higher absolute speeds.
The low speed tests that Mister Fork is doing highly favor the light aircraft. Those same light aircraft that frequently have realtively low top end speeds.
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Not a valid point Karnak. I'm measuring accleration rates, not a measure to top speed. The acceleration rates of aircraft at where Vf and Vo were not affected by top speeds or drag limits. We all know that a P-51D is a speed demon comparied to a Spit V/IX but the Spit IX is a fast accelerator.
The problem is that if I increased Vo to 250, then other factors will play a role like top speed limits. Most planes accelerate at that factor up to their drag limits when the last 10% of their top speed is a slow crawl.
It's why Car and Driver and 99% of other automotive acceleration tests measures 0-60Mph, not 30-90, 100-160 etc.
I will point out that at 25'000 feet, the test results are different again. The Spit IX takes 67 seconds from 175-275, while the Mustang takes 39.