Special Aircraft Service

Individual Mod Downloads for IL-2 1946 => Other Mods => FM Discussions => Topic started by: brettt777 on February 02, 2012, 11:42:21 PM

Title: Flaw in flight models when dogfighting
Post by: brettt777 on February 02, 2012, 11:42:21 PM
So I flew several different dogfight scenarios this evening and maybe it's just me but there seems to be a serious flaw in the flight model when dogfighting. In every scenario, no matter what plane I was flying or what plane I was flying against, if my oposition was in the air, i.e. if I hadn't shot him down (didn't happen very often) of if he hadn't crashed, as long as he was in the air, my plane was seriously lacking in power and airspeed. For instance, I had a P-51D against an FW-190. Fairly even for the most part although the Mustang has a speed advantage at altitude. At just above sea level when I was either being pursued or in pursuit, I could barely get 230-240 KIAS. He didn't seem to have any problem at all with his airspeed and being able to climb at will. So, I tried it against a 109 in the rookie setting. Being a rookie, he crashed not long after I got airborne. All of a sudden I could get 300 plus KIAS in level flight. I put an F9F againt a 190, also a rookie. At altitude, chasing the 190, I was turning about 88% rpm and could barely get 250 KIAS. After I eventually got close enough to shoot him down, I suddenly had tons of power and speed. I could cruise at just under 400 KIAS at about 85%. What's the deal? I know I am not imagining this. I tried this with about 8-10 different scenarios and every time I saw the same thing. As long as there was an enemy in the air, I was down on power and airspeed. Oh, and if I took my eye off him for more than a second or two, he would vanish, and then magically be able to loop back around undetected and be right on my tail in only a few seconds. So has anyone else noticed this or does anyone even dogfight in single player mode? I will eventually try mutiplayer and fly against real sim pilots but I'm not real good at the dogfight yet.
Title: Re: Flaw in flight models when dogfighting
Post by: BT~Tarik on February 02, 2012, 11:53:19 PM
You are most likely doing something wrong with your engine management. What prop pitch do you fly with when chasing the enemy ? If you are rather low then no wonder why you are so slow.

Also very often the AI climbs when it is being chased, and if you don't have a speed advantage you will loose speed quickly. The AI won't (if you play not on DBW  but another 4101 version, it's always good to tell what game version) because it doesn't overheat and so on.

Maybe if you manage to shoot him down you level again and or lose some altitude, that's maybe why you speed up then.

I don't have this problem in DBW, and I only play offline.

As I said it's probably you who is doing something wrong.
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on February 03, 2012, 01:10:51 AM
I'll just throw in here too-190>mustang at low alt.
Hell, I started a whole thread on the subject  :D

However, I cannot duplicate your problem in DBW. Please more details on your game version.
Title: Re: Flaw in flight models when dogfighting
Post by: brettt777 on February 03, 2012, 07:45:46 AM
Well, the Mustang may have a slight disadvantage at low altitude against a 190, but a Bearcat doesn't (the Bear was actualy modeled after the 190, sort of). And I had the same situation with it. Trying to chase down the 190 (or even the 109) straight and level because I certainly couldn't keep up with his rate of climb even thought they are rated the same, I could barely get more than 250 KIAS. Throttle and prop pitch, maxed out or set up for cruise, made no difference. If I flew the exact same plane at the exact same altitude and exact same load out, only no enemy aircraft, I could easily cruise at around 300 KIAS without working the engine hard. And as I said last night, it's not just the prop planes that I noticed this with. The jets are the exact same way. I tried the Sabre, the Panther and the MiG-17 and all of them did the exact same thing; enemy in the air, way down on power and speed. No enemy in the air, plenty of power and speed. I'm not sure how to do it but I will try to make a recording of this and let you guys see it so you'll know I'm not making this up. Yes, I am a rookie when it comes to aerial combat but I definitely know a thing or two about airplanes (twelve years in US Naval aviation, working on L-39s for a living for the last 4 1/2 years).
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on February 03, 2012, 09:06:26 AM
What game version?
Title: Re: Flaw in flight models when dogfighting
Post by: brettt777 on February 03, 2012, 09:40:47 AM
Oh, sorry. Should have put that in there before. It's IL2 1946 obviously, patched to 4.10.1 with the latest buttons and Modact version 3.06.
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on February 05, 2012, 01:39:39 AM
Well Ive tried in DBW and UP3.
I cannot, under any circumstances duplicate your results.
Title: Re: Flaw in flight models when dogfighting
Post by: HundertzehnGustav on February 05, 2012, 03:51:59 AM
move to FM discussions... anyone?
*refrains from commenting*
Title: Re: Flaw in flight models when dogfighting
Post by: brettt777 on February 06, 2012, 03:31:52 PM
Well, I will try it again this evening and see what happens. Maybe I'm missing something. It certainly wouldn't be the first time...
Title: Re: Flaw in flight models when dogfighting
Post by: sluggs on February 07, 2012, 01:34:36 PM
While it's slightly off topic, I've found that the Allison-powered P-51A completely dominates 190s and 109s at see level. I've never really fought them at high altitude (unless the enemy does that bullshit "constant climb," and even then the P-51A can keep up), but bellow 15,000 feet, the P-51A is a monster. I think it's already been said that the stock P-51s that come with the game under perform for some reason.
Title: Re: Flaw in flight models when dogfighting
Post by: FANATIC MODDER on February 07, 2012, 02:01:25 PM
It all comes to lighter weight. Take off weight in P-51B/Cs is less by approx 200kgs in comparison to P-51Ds and P-51As are even lighter.
Title: Re: Flaw in flight models when dogfighting
Post by: LuseKofte on February 07, 2012, 03:54:54 PM
While it's slightly off topic, I've found that the Allison-powered P-51A completely dominates 190s and 109s at see level. I've never really fought them at high altitude (unless the enemy does that bullshit "constant climb," and even then the P-51A can keep up), but bellow 15,000 feet, the P-51A is a monster. I think it's already been said that the stock P-51s that come with the game under perform for some reason.

The P-51 with allison engines was superior at low level, it was very fast at sea level and was redrawn as a fighter by RAF, because of its bad performance at altitude. As a low level ground attack role and recon it was prefered by English pilots
Title: Re: Flaw in flight models when dogfighting
Post by: Whiskey_Sierra_972 on February 08, 2012, 01:53:46 AM
Not always a new version of a plane is a pure better performance plane than older because it can be updated to have better performance at a different height performance as P51 was changing engine from Allison to Merlin , to be a more effective weapon platform as 109G towards the F and so on!

Before all try to search for that version you are comare and look if something is wrote about their difference...then try to think what those change can alter the performance between them...
Title: Re: Flaw in flight models when dogfighting
Post by: Roger Smith on February 23, 2012, 12:20:32 PM
the new FM is biased, almost nothing but Russian stuff can catch up with anything else

the jets feel very underpowered too, the only good plane with both speed and maneuver anymore is the Me-163
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on February 24, 2012, 08:15:10 PM
So what, exactly, are you basing these opinions on?
And which version of IL2 are you talking about exactly?

FM's are all biased? Come on man, thats sooooooooo 2005.
If its really that bad please, post up a new thread with some numbers. Im sure wed all be interested in something more concrete than your opinion.

I know its not "Ace Combat" *sneer* but its closer than any other sim out there in its current DBW state.
Title: Re: Flaw in flight models when dogfighting
Post by: Roger Smith on February 24, 2012, 10:00:28 PM
I may have been too quick to say biased, or maybe it was just a too strong word. I'll re-check the P-51 speed on IL-2 compared to real life data later.
as for the Ace Combat thing: it's not that the controls feel more realistic it feels more arcade now. Also, it feels weird... the planes can turn on a dime in one dogfight and at the next it all of a sudden feels like a cow.
Title: Re: Flaw in flight models when dogfighting
Post by: HundertzehnGustav on March 05, 2012, 12:45:27 PM
uh... a dime,
the american ten cents piece? (17.91 mm)
or the canadian one? (18,03 mm)

because that is a huge difference.
But maybe it is just your joystick not being calibrated?

Numbers... numbers are what one can work with in FM discussions...
Title: Re: Flaw in flight models when dogfighting
Post by: Roger Smith on March 05, 2012, 05:58:20 PM
AI does the impossible everytime I fly, it's one thing to have superhuman reflexes, but the planes themselves do the impossible. Bf-109s turning like a Zero and maintaining that high speed while turning, and right when they get behind you they all of a sudden gain a nice amount of acceleration, catching up to F-86s and MiGs with no problems.

Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on March 05, 2012, 07:19:14 PM
Your either exaggerating or doing it wrong.
And I mean really wrong.
Title: Re: Flaw in flight models when dogfighting
Post by: 256th_Killer9876 on March 14, 2012, 06:38:42 PM
Actually, Solo isn't exaggerating I have the same problem and I've been flying the sim since it came out in '01. In a P-51D at altitude at cruising power I'm at 280mph but when I increase to combat power because I see a flight of 109s I all of a sudden my speed drops down to 190 to 210 mph, and I get shot down.
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on March 14, 2012, 08:07:22 PM
Then I stand by my previous statement-your doing something wrong.
Have a detailed account? Ive been flying this sim for 10 years now and never noticed anything like this.
Are you managing your PP correctly in the 51? Remember too that it bleeds energy like a stuck hog.
Title: Re: Flaw in flight models when dogfighting
Post by: 256th_Killer9876 on March 15, 2012, 02:33:35 PM
yeah because I increased my Prop Pitch from 85% to 100% to get the highest performance and then thats when I experienced the speed drop. (With the Increase of the throttle of course)
Title: Re: Flaw in flight models when dogfighting
Post by: CWMV on March 15, 2012, 03:29:35 PM
That may have something to do with it.
100% pitch does not give best speed. It's good for acceleration, but full prop pitch won't make you go faster. In fact in a dive its a wonderful air brake.
Title: Re: Flaw in flight models when dogfighting
Post by: dhtsword on April 05, 2013, 07:32:11 PM
That may have something to do with it.
100% pitch does not give best speed. It's good for acceleration, but full prop pitch won't make you go faster. In fact in a dive its a wonderful air brake.

Well, atleast up to 4.09b (which I use and have the classfiles) this statement is somewhat wrong.

The IL-2 engine is doing the following (based on very real world behaviour) with the Prop type of the P-51 (PropAnglerType 1) which is the standard "constant" speed type.
If you manipulate the Prop-setting you actually choose a RPM ranging from PropAnglerMinParam (1500 RPM) to PropAnglerMaxParam(3000 RPM).
Let's say you chose 3000 (100 % Prop) and 100% Throttle and then go to 110% Throttle or WEP:
1. Engine generates more power
2. At the current aerodynamic Prop AOA this would create more revs
3. Now the Prop governor increases Prop AOA so it stays at 3000 RPM
(In case PropPhiMax is exceeded no more correction is possible -> Revs will go up)
Now this increase in AOA will generate more thrust -> aircraft will accelerate until sum of drag is equal to generated thrust.
Around 95% of all prop driven aircraft in IL-2 use basically this constant speed type of prop. If you set it to "Auto" the Prop is linked to the throttle setting giving different RPM settings for Throttle settings.
If it really happens that an AC decelerates at full throttle when upping the Prop to 100% something is broken big time in the respective game version (either FMD(buttons) or Code).

The magic in IL-2 is that in using prop tuning one can have the equivalent of  +/-1000 HP:
1. Very high Prop-RPM (high Reductor settings, I have seen > 1.0 settings !!!!) -> high Propblade velocity which the game calcs as: square root of(((0.375 x Propdiameter x Pi x rev/s x propreductor)squared) x (airflowV)squared) up to 300 m/s brings only benefits and only small penalty for "supersonic" Props above 300 m/s.
2. PropAnglerSpeed is actually degrees per frame which for 4.09 means degrees per 0.03 seconds (later game versions use > 0.03 s per frame). So the 3°/s of the VDM Prop for instance are 0.09 IL-2 PropAnglerSpeed. If you up this value to 0.15 or higher you will experience dramatic performance improvements of the aircraft.
Together with reductor settings you can easily create a total dog with a 2000 HP engine or an UFO.
Now one cannot really take over real world data into IL-2 unseen (eg. Propreductor settings) because the IL-2 engine abstracts the prop functioning to much for that. So one can only finetune for correct hard fact values as climbrate, level speed but level-, dive- and climb- acceleration can only be guessed. Although for level acceleration the distance needed to takeoff is a very good indicator, because allmost all Aircraft Handbooks give values for that.
Title: Re: Flaw in flight models when dogfighting
Post by: Fresco23 on May 06, 2013, 03:06:28 PM
Actually, Solo isn't exaggerating I have the same problem and I've been flying the sim since it came out in '01. In a P-51D at altitude at cruising power I'm at 280mph but when I increase to combat power because I see a flight of 109s I all of a sudden my speed drops down to 190 to 210 mph, and I get shot down.

what altitude??
and what are is considered "cruising power" in a P-51D??
I ask because I want to try this also...