PDA

View Full Version : Why is F4U so slow at Sea level



Markw4
12-27-2005, 03:30 PM
The top speed I can sustain in the F4U-1D or -1C on the deck is 550KPH/341MPH. The F4U-1D/c should be capable of between 355MPH to 360MPH with Pylons attached and 350MPH with pylons and rocket stubs. Without pylons or stubs in the clean condition it should be capable of 366MPH at sea level. I can provide Navy, Vought NAVAIR and TAIC references for this speed.

The F4U-1A with the full 2250HP as specified in PF should be a 360MPH at sea level and the 1944 F4U-1A at 2300HP should be at 366MPH as well on the deck. I can provide reference for this as well. I can only get 540KPH out of her. About 30MPH to slow.

I am testing trimmed for level flight 110% power Nuetral Blower (mislabeled as no blower) auto rich.

Is anybody minded the farm on these FM's?

http://home.comcast.net/~markw4/air1777speed.jpg

Markw4
12-27-2005, 03:30 PM
The top speed I can sustain in the F4U-1D or -1C on the deck is 550KPH/341MPH. The F4U-1D/c should be capable of between 355MPH to 360MPH with Pylons attached and 350MPH with pylons and rocket stubs. Without pylons or stubs in the clean condition it should be capable of 366MPH at sea level. I can provide Navy, Vought NAVAIR and TAIC references for this speed.

The F4U-1A with the full 2250HP as specified in PF should be a 360MPH at sea level and the 1944 F4U-1A at 2300HP should be at 366MPH as well on the deck. I can provide reference for this as well. I can only get 540KPH out of her. About 30MPH to slow.

I am testing trimmed for level flight 110% power Nuetral Blower (mislabeled as no blower) auto rich.

Is anybody minded the farm on these FM's?

http://home.comcast.net/~markw4/air1777speed.jpg

ImpStarDuece
12-27-2005, 06:53 PM
Is your radiator closed or open?

With open radiators I can indeed only sustain 555 kph/ 342 mph in a F4U-1D.

With closed radiators I can sustain 576 kph/ 358 mph in a F4U-1D, so thats about spot because it has the rocket rail stubs modeled.

With the F4U-1A i can sustain 577kph/ 358.5 mph, so, if it really is the 2250 hp model, its only about 3 kph/ 1.5 mph too slow.

Markw4
12-27-2005, 09:49 PM
I went back and verified my radiators are closed and they are. I am stuck at 550KPH.

I checked a few other A/C to verify my results and I am getting 570KPH out of the P-38L late model which seems to fast and I am getting 580KPH out of the P-51D-25 which may be a little slow. Also I tested the P-47D and got the 550KPH again.

I am using Low Blower, 100% prop pitch, closed radiators, auto rich and 110% WEP at 20 meters off the water.

How do I get rid of the drag chute behind me??

BTW, how are you getting exact speeds? Mine are in 10KPH increments.

neural_dream
12-27-2005, 10:47 PM
Oh, I see, you didn't get TAS. You measured IAS. For TAS you need to fly cockpit off (ctrl-f1).

I know, in theory they should be the same at sea level. They aren't.
In my aircraft reference guide (under my sig) among others I have all sealevel and max speeds. You may want to check it out.

Kuna15
12-28-2005, 03:56 PM
Also don't forget to test on Crimea map, time: 12 o clock, clear weather.
Those are valid testing conditions for all planes in game, maybe result will differ a bit from map to map (I'm actually sure of that example being overheat; on desert map overheat is quicker).

VW-IceFire
12-28-2005, 05:55 PM
Make absolutely sure that Complex Engine Management is on in the control panel.

Tully__
12-29-2005, 05:14 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kuna15:
Also don't forget to test on Crimea map, time: 12 o clock, clear weather.
Those are valid testing conditions for all planes in game, maybe result will differ a bit from map to map (I'm actually sure of that example being overheat; on desert map overheat is quicker). </div></BLOCKQUOTE>
Test results of real aircraft are "adjusted" to a standard set of conditions. The only map in the game with standard conditions is Crimea, so what Kuna says is correct. Also, as NeuralDream has indicated TAS will not be the same as IAS except at sea level in standard conditions. On any map except Crimea you can expect the IAS to not match TAS at sea level. On some winter maps (only found in the merged version), IAS will be higher than TAS at sea level.

Grey_Mouser67
12-29-2005, 04:02 PM
I didn't know the -1A had a 2250hp engine...I thought that wasn't released till the -1D model

The planes have identical FM's which I had thought was erroneous. I do concur with the speed testing mentioned above...I can get 576km/hr out of it at sea level and at 6000 meteres which is right at the Corsair's critical altitude I can get 672 out of it which is a bit better than the -1A figures I have by 3 mph and a bit slow to the -1D figure by 5 mph...although the critical altitude of the D was something like 1000 ft higher.

Anyways, I find the plane to be well modelled in speed. If there is a difference it might be in climb but I don't know what convention to use in climb modelling so I look at aircraft relative to each other and I think the Corsair does fine there.

If I do have a complaint...and it is a big one...it is the case of Parkinson's disease the Corsair has developed...it is the wobbliest of the wobblers and this needs to be addressed. Was flying with a fellow yesterday who flies primarily Fw's, 109's and Spits...he took his first ride in the hog with me...we were on Teamspeak. First thing he asks is if he can trim the plane to fly straight...i laughed and said yes...he said it doesn't hold still...i confirmed and told him to wait till he tried to shoot something!

Hope Oleg addresses this issue above all...I like the Corsair as is...one of his better models I think, just need to remedy the wobbles in it.

stansdds
12-30-2005, 04:51 AM
The R-2800-8W (water injection) engine was installed during the production run of the F4U-1A/FG-1A/F3A-1A, beginning with:

Vought 55910 (573 produced)
Goodyear 13992 (1009 produced)
Brewster 11208 (85 produced)

Unfortunately, Oleg modeled all of the Corsairs identically in terms of engines and bomb capability. None of the -1's had water injection.

The -1 and -1A only had the centerline hard point, originally intended for a 170 gallon drop tank, but field units were the first to rig a bomb rack with a 1000 pound capacity.

The twin pylons are correct for the -1C and all later Corsairs.

As far as the wobble is concerned, I'm convinced my Corsair has a bad case of the DT's!!!