P-47D-25 Performance

[nickle]

I compared Acft.cfg numbers to the Republic designer numbers. Article 1945:
http://www.rwebs.net/avhistory/history/p-47.htm
Differences in prop size, root chord, empennage area.
Modified to suit in the cfg file.
Flight tested for speed at SL per cfg 351 mph max TAS SL.  As modeled, speed was 20 mph under max.  Engine specs are ok in cfg.  Adjusted prop thrust_scalar to 1.26 to hit 351 mph, 50 pct fuel and FAMMO.  Turning dive to 600 ft, 400+ mph, idle, decel to 300 mph, mil pwr for the test. Set pitch_stabilty to 1.3.  A sweet flying machine with performance it should have.
Noted 51 and 38 with similar speed deficiency.  51 to 1.1 and 38 to 1.15 prop thrust_scalar.  Also adjusted stabiltity.
Test of 3 US 190-9 shows this fighter flys well as modeled.  Small change in thrust_scalar to 1.05 to hit SL speed mark of 357 mph and roll_stability to 1.3 to suit.

[snake]

I will have to give that a try nickle, thanks for the info.  I'll let you know what I think.

[snake]

Great job nickle, that is just what the P-47 needed.  Those small changes make a huge difference in how the plane handles.  8)

[nickle]

The 3US P-47D-25 is no more.  Replaced by the -26 at AvHistory. The designations are real.  The -25 was the initial upgrade by Jerry Beckwith and the -26 is by the gregory group.  Same for other 3US fighters.  Current workbook is V2.82.100. Old is .36.
The newer model supercedes the old.
Difference: The newer model doesn't require any stabilization changes out of the box. Major improvement is gun ballistics and impact damage. Downer is that the P-47 as modeled is a slug at SL Mil power.  319 mph mil max.  Top is 337 mph in WEP.  WEP = War Emer gency Power. Don't know why this is the listed SL max speed as it requires Water Methanol, WM, to attain.  The -25 had 400 + seconds WM, new 600 + seconds.  The WM tank was located on the firewall behind the engine. Am skeptical that it had 600 seconds.  WEP imposed exraordinary loads on the engine for 300 additonal HP. Usually required breaking a thin copper wire on the throttle to disclose to maintenance that WEP was used as the engine had definite overpower limits.  Some engines increased RPM also but not the 47.  Have some sites on P47 that I'll post separately.