Etask Posted Wednesday at 11:15 PM Posted Wednesday at 11:15 PM 11 ore fa, cw4ogden ha scritto: No where does he mention 23,000 feet for the 261 knot reference. "2,500ft all they way up through 15,000 ft" If you are willing to look past at least 8,000 feet pressure altitude discrepancy, then yes everything is ok. I tested at 23,000 with 50% fuel, full blower, 2700 rpm all cooling flaps closed, mixture rich, and maxed out at 243kias which translates to about 402mph true. Not bad, but not correct either. Those results were achieved with a dive from 24k to 23k, then waiting until the speed stops decaying. It's even worse with a level acceleration coming in at around 236kias. At sea level with a dive I can get about 289kias which is about 332mph true. With about 275kias achievable in level acceleration. Aside from the OPs hyperbolic post, no one is saying it's off by a huge amount. But it's missing 5-10% of top speed as a rough estimate. Well, I am not looking past 8000ft PA discrepancy, nor I am saying the flight model is correct. I did actually say it does need work. My point was, if people complain about the speed while not realising we are talking about different speeds (indicated vs true) and different units (knots vs mph), it just creates a lot of confusion. First message in this thread: ”this thing barley does over 200 mph, even stripped down with no fuel..” it is simply not true. This thing actually does well over 200mph even at full load. If we wanna talk about that 5-10% difference and other oddities in this module I am open to it, it definitely needs work and tuning; however let’s not spread wrong and misleading info. 1
cw4ogden Posted Thursday at 10:08 AM Posted Thursday at 10:08 AM 10 hours ago, Etask said: Well, I am not looking past 8000ft PA discrepancy, nor I am saying the flight model is correct. I did actually say it does need work. My point was, if people complain about the speed while not realising we are talking about different speeds (indicated vs true) and different units (knots vs mph), it just creates a lot of confusion. First message in this thread: ”this thing barley does over 200 mph, even stripped down with no fuel..” it is simply not true. This thing actually does well over 200mph even at full load. If we wanna talk about that 5-10% difference and other oddities in this module I am open to it, it definitely needs work and tuning; however let’s not spread wrong and misleading info. I get your point, and I'm not trying to be rude or inflammatory. I want it fixed. I want the product I purchased to live up to the fidelity level we've come to expect from DCS. Currently it doesn't. I'm willing to help that process, but it's maddening to put hours of effort into testing, only to have someone else chime in half-cocked that everything is hunky-dory. Your comment summarized is "Did you consider the nuances of aviation airspeed?". And the answer here and in other similar threads is yes. The nuances of of true versus indicated and knot versus miles per hour were calculated, and it's still coming in slow. My grievance isn't with you individually, it's DCS forums thing. No matter how much data you provide, there's always contingency who argue in the contrary. Almost like disagreeing for the disagreeing's sake. And it results in the inability to even substantiate something is a bug, like where we are with the F4u. This hasn't even been acknowledged as a bug yet. 1
Etask Posted Thursday at 01:39 PM Posted Thursday at 01:39 PM (edited) 3 ore fa, cw4ogden ha scritto: I get your point, and I'm not trying to be rude or inflammatory. I want it fixed. I want the product I purchased to live up to the fidelity level we've come to expect from DCS. Currently it doesn't. I'm willing to help that process, but it's maddening to put hours of effort into testing, only to have someone else chime in half-cocked that everything is hunky-dory. Your comment summarized is "Did you consider the nuances of aviation airspeed?". And the answer here and in other similar threads is yes. The nuances of of true versus indicated and knot versus miles per hour were calculated, and it's still coming in slow. My grievance isn't with you individually, it's DCS forums thing. No matter how much data you provide, there's always contingency who argue in the contrary. Almost like disagreeing for the disagreeing's sake. And it results in the inability to even substantiate something is a bug, like where we are with the F4u. This hasn't even been acknowledged as a bug yet. Well, I agree with you, didn’t wanna “argue in the contrary”, we’re here for the same goal. It’s just that sometimes people consider bugs things that are not bugs (not just in the Corsair, in all modules). Opening (yet another) thread saying this thing flies 200mph at max power and is severely underpowered is not gonna help anyone, devs are just gonna disregard it. It is frustrating because I would also love this module to shine, not just because I’ve paid for it…but because I truly love this aircraft. And to be clear, I also think it flies slower than it should. Edited Thursday at 01:40 PM by Etask 2
Katj Posted Friday at 11:56 AM Posted Friday at 11:56 AM On 9/1/2025 at 9:18 PM, some1 said: This is a bold assumption. Unless you are in a relatively narrow band below supercharger critical altitude and won't pull back the RPM too much, the engine will not be able to produce the same manifold pressure at lower RPM. The superchargers are gear driven and directly linked to engine speed. A small drop in RPM is a relatively large drop in boost. For example R-2800-8 from F4U-1 is rated at 2000 BHP at 2700 RPM, but only 1675 BHP at 2550 RPM. Also, just because you have the same manifold pressure at lower RPM does not mean the engine is producing the same power. On the contrary. Otherwise, it would make no sense to spin it faster. I don't have a full power table for R-2800, so here's something more meager from Lycoming. Same principles apply. This is the reason I've been experimenting with running the jug at RPM upwards of 3000 and boost around 75". Poor engine doesn't last long at those settings though, but you can certainly increase RPM a little bit above 2700 and gain a few horses.
stelr Posted 5 hours ago Posted 5 hours ago I'm in the camp of "there is a problem with speed and engine management." I am NOT a real pilot, but I just find it hard to believe that the 2800 Wasp was as delicate and prone to catastrophic damage when running over recommended limits found in the manuals for each version. On CV takeoffs, if I push the throttle full forward (max), the engine begins metal banging sound before I clear the island, with my wheels not even off the deck!. less than a min later, even with reduced manifold pressure (~40 in) and reduced pitch (2500 RPM), the engine seizes and I'm in the water. I doubt the navy would accept any engine that cannot stand some abuse, especially one that must engage in combat where one will eventually have to overstress the engine for short periods to survive. Manufacturers/engineers always put in hefty margins on recommended settings to ensure their product runs well for extended periods, knowing that their product can really do more, safely. Just look at CPU and GPUs for example. OC'ing is routine and even done by the manufacturer if requested in some cases. Built in safety margin. But I digress. One last point. Many here talk IAS vs TAS, and even CAS. Likewise, we talk mph and kts. I would recommend we try to all use IAS and mph in future discussion so that we are all on the same page and avoid confusion. IAS is what your instruments read in the cockpit, so that is easy enough to report without any additional computations. Also, if i read correctly from another source, IAS was what was usually used in actual tests results of the real aircraft. I recommend mph so it is easier for quick comparison to its other Allied aircraft. I understand that one must still convert to kph to compare to Axis aircraft, but at least we won't have three options (i.e. kts). Just my $0.02. (and, that's what it may be worth.) v/r Stel
Saxman Posted 1 hour ago Posted 1 hour ago 4 hours ago, stelr said: One last point. Many here talk IAS vs TAS, and even CAS. Likewise, we talk mph and kts. I would recommend we try to all use IAS and mph in future discussion so that we are all on the same page and avoid confusion. IAS is what your instruments read in the cockpit, so that is easy enough to report without any additional computations. Also, if i read correctly from another source, IAS was what was usually used in actual tests results of the real aircraft. In which case I would use IAS and kts, because kts is what's actually on the dial, and I believe it's what the original POH used.
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