|
|
|
|
#1
09-25-2013, 07:53 PM
|
|||
|
|||
Horseback, going back to PP and CEM questions. I tested it on F4F-3, going 95%to90% does get a higher speed, especially with a little nose down attitude. However, it only works on a certain altitude. I remember hearing someone say different altitude has different PP settings. The learning curve is pretty steep in the field of CEM. Wanna set up a new thread to discuss PP and throttle settings in more details?
|
|
#2
09-25-2013, 11:56 PM
|
|||
|
|||
|
Quote:
I had a thread that centered on acceleration tests the last three or four months; a lot of useful information can be found there, and if you can find the Pilot's Notes for the Martlet or F4F somewhere, there will be some Good Stuff there too. Simply put, though, the Wildcat was a classic case of the underpowered fighter. It's too heavy for the horsepower it has (and the FM-2, which was over 500 lbs lighter and had an extra 200 horses below 20K ft PLUS being that little bit aerodynamically cleaner simply doesn't have an FM that reflects that). According to America's Hundred Thousand, the Wildcat was pretty low drag but that little R-1830 wasn't enough for serious performance (and an R-2800 was almost two years off). The Bearcat, which was the ultimate expression of the R-2800 powered fighter, looks a lot more like an FM-2 with a cut down rear fuselage and a bubbletop than it does like a refined Hellcat to me. cheers horseback
|
|
#3
09-26-2013, 01:55 PM
|
|||
|
|||
|
Quote:
|
|
#4
09-26-2013, 10:35 PM
|
|||
|
|||
|
horseback. I went back to re-read your thread on acceleration tests. In there, you noted that 310+mph, 2700 accelerates better than 3000 for P51. I just wonder that from your experience if that's the case for all other US planes, such as F4u, F6F and P-47. Because you mentioned 3000 works for all speeds for spitfire, that makes me wonder if acceleration physics are modelled differently for different planes. Also, when you reduced your RPM down to 2700, did you simotanously chop throttle or you just maintain the max power all time?
|
|
#5
09-27-2013, 01:14 AM
|
|||
|
|||
|
Quote:
The Mustang's throttle control is kind of unique though (it controls manifold pressure directly, if I understand the manual correctly where most other aircraft's throttles just control how much fuel goes into the engine), and when testing the Spitfire Mk IX, which had essentially the same engine (and was lighter, but with a good bit more drag), I didn't get the same results at 2700 vs 3000 rpms. The same is true with the P-38 and the American R-2800 powered fighters--they just don't react like a stick-shift car's transmission where you can put it in low gear (highest RPM) and gradually move up to higher gears (and progressively lower RPM) while accelerating at the same pace. Greatest constant state acceleration was obtained by shoving the throttle and prop pitch levers all the way forward and going all out until the engine overheated and then going for another 30 to 60 seconds or so, depending upon the aircraft (all the while mashing the nose down trim and adding rudder trim as required, and then in some cases, having to add nose up trim over certain higher speed ranges). You CAN reach a desired speed and then lower prop pitch and get a temporary 'pop' in speed, but you can't keep the extra acceleration going by lowering your prop pitch some more--it's like putting too much strain on your engine, and making it work harder than it was designed to (like a bicyclist going uphill in too high a gear). What you want to do is get close to the speed you desire and then smoothly lower your prop pitch, allowing the engine to take advantage of the momentum you've built to reach that last bit and maintain your speed without overheating. I also find that the better your power to weight ratio, the better your acceleration BUT drag is the ultimate limiter, and it increases on a steadily rising curve relative to speed. The Zero has a pretty good power to weight ratio and a spectacular acceleration at lower speeds, but it is larger than the Bf 109 and it has a really draggy high-lift wing, so the drag overpowers the engine fairly quickly once it reaches 370 to 400 kph or thereabouts. At least that is what I found at 10,000ft/3000m and below. I find that for the R-2800 powered fighters that the manual warns you not to keep high rpms during a dive; in fact, the recommended rpm for an extended dive is 2250, or close to 75% prop pitch. That will give you a pretty fast dive if you do it properly; you won't need much more than 60% throttle if you're taking it down over 3000 ft from your starting altitude. The Corsair and even more, the Hellcat in this game exhibit an increasing nose-down attitude as the speed goes up. It seems to be a steady decrease in nose angle semi-proportional to speed, unlike the FW 190A, which has a sudden nose drop of a few degrees at (this is from memory, so don't bank on this) around 220 mph/ 360 kph and then stabilizes. These two USN birds just keep gradually tipping forwards, although the rate is greatest around 300-400 kph (160-220 knots) IAS. If you don't keep track of this, you can mess up your firing solution in a diving pass. Your gunsight's center will not stay in the same spot if you maintain a straight line course even in a dive if your speed increases significantly; you have to 'aim' for a spot a bit farther ahead of your target than you would normally expect, and your diving gunnery pass will need to become shallower as you reach firing range. Hope this helps. cheers horseback
|
|
#6
09-27-2013, 02:32 PM
|
|||
|
|||
|
The last few sentences are very true. I always add a bit of up trim to maintain sight ahead of target. Btw. I don't know what hotas you use. I am using x52pro. I find using rotary for elevator trim is whole lot better than POV hat. Rotary helps you get to your desired trim quicker. Just a suggestion, you may want to try it. For rudder trim, I am still using POV hat. Thinking about moving that one also to the other rotary.
|
|
#7
09-27-2013, 08:06 PM
|
|||
|
|||
|
Quote:
The CH Products gear can be combined into one 8 axis, 32+ button unit and another 4 axis, 12 button unit using the CH Manager software, and I find it invaluable for Il-2 Sturmovik '46 (not so much for FSX or DCS P-51D, which are far more flexible about the number of controllers). I've had my stick and pedals for over eleven years, and they work as well as they did the day I got them. The throttle came about a year later, and the Quad about six years ago (and except for the CH Control Manager software advantages, the Quad could be more cheaply replaced with two Saitek throttle quads in most cases). These are both as reliable as the stick and pedals, and show little evidence of their ages and heavy use. I have an old 'vanilla' X52, but the stick is IMHO execrable both aesthetically and in terms of button locations and overall feel. It is waaaay too busy, even for monodexturous right-handed dweebs like me. My right hand should be dedicated to controlling the airplane, not pushing buttons (the act of reaching for some stick buttons with it during combat has thrown me into stalls and worse). My CH Fighterstick is more precise in its axes and more balanced button-wise (and it looks more businesslike for my non-flight sim nutjob friends and acquaintances when they visit). The X52 throttle, on the other hand, is nice but grossly under buttoned in contrast to the stick; I like the weight and feel of the main axis, the dial pots and the slider, but everything else...ick! The centering of the pots on my X52 was a bit hard to locate by feel; I had to use a finepoint brush and some of my old Polly S acrylic modeling paints to mark out the centerpoints on the two rotary pots --looking at the red lines on the rotary dial and the body of the throttle tells you at a glance where you are trim wise. To keep the paint from wearing away with heavy use, cover your lines with clear varnish (fingernail polish is ideal, if you have a friendly source) once the original painted lines fully cure (about two or three days, depending upon local humidity). My younger son still uses it occasionally in tandem with a TM 1600, and we're trying to convert the stick into a button bay (without that comic book handle), but it is currently unused and in pieces at the moment. If I were to design a HOTAS type throttle controller, I'd replace the attempts to put a 'mouse' capability with a four-way switch or a slider/dial pot combination and there would be no buttons at all on the base; in fact, it would be a hybrid of the X52 throttle and the CH Pro Throttle with the buttons of the CH Pro and the slider and dial pots of the X52. I prefer the feel of the X52's throttle axis and its heavier base, but the shape (and color) of the handle would be more CH-like. I'd also like to give the player a means of anchoring the average flight sim controller so that they aren't sliding around the desk, or in the case of pedals, across the floor. Hartmann and Bong never had to worry about their sticks coming up off the cockpit floor, or their seats suddenly being too far from their pedals. Having everything in exactly the same spot every time you fire up your favorite sim shouldn't be so hard. cheers horseback Last edited by horseback; 09-27-2013 at 08:09 PM.
|
 |
|
|
Hybrid Mode
