The purpose of this test is to determine the best altitude(s) to switch the supercharger (SC). I did this test because while doing a F6F ROC I realized that the real world altitudes specified in the real world data (RWD) were NOT the best altitudes for the game. To determine what those altitudes are I had to do a test per SC setting. The F6F-3 has three different SC settings:
SC1 MAIN
SC2 AUXILIARY LO
SC3 AUXILIARY HI
The altitudes at which the ROCs cross over is the best in-game altitude to switch the SC.
REAL WORLD DATA PROVIDED BY M. WILLIAMS:
http://www.wwiiaircraftperformance.org/f6f/f6f.html
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U.S. Naval Air Station
Patuxent River, Maryland
April 24, 1945
Evaluation of Maximum Practicable Combat Power Rating
For the Model F6F-3 Airplane on
Model F6F-3 Airplanes Nos. 04934, 41420, 42633
TED No. PTR-0414
IN-GAME TEST CONFIGURATION:
MAP: Crimea
WEATHER: Clear
TIME: 12:00PM
FUEL: 100%
WEAPON LOAD OUT: DEFAULT
RAD: Initial two than adj at needed.
POWER: 110% and WEP
ROC TEST METHOD:
The ground start method begins at a stop on the runway with the brakes on. The time to climb (TTC) stats when the brakes are released. The pilot completes a normal takeoff with rapid gear and flap retraction. The airplane is allowed to accelerate at low altitude to a speed somewhat below the speed for best climb speed (BCS). The pilot then performs a fairly abrupt pull-up and attempts to stabilize on the BCS schedule at the lowest practical altitude. Once stabilized on the climb schedule the pilot will adjust speed as the airplane climbs so that the schedule of best-climb speed is maintained as the altitude increases. The check climb ends when the rate of climb drops below 100 feet per minute or when a pre-established maximum altitude has been reached. Depending on the plane type, the time it takes from brakes released to lift off vary from about 20 to 40sec for a fighter. For graphing purposes, and to give the in game plane the best chance of meeting it's TTC values I removed the time between the brakes released and lift off (i.e. ROC > 0). This can cause a shift in the TTC times at alt by about 20 to 30sec.
RESULTS:
As you can see from the graph, for the 60"MP case (32.8" Carb Impact) the best altitude to switch from SC1 to SC2 is at 5,700ft (RWD 9,500ft) and from SC2 to SC3 is 16,250ft (RWD 14,500ft). Also note the BEST CASE ROC point-to-point line is manually added and consists of the best ROC per SC setting. This is a sort of prediction of what the ROC will be in a ROC test where the SC is switched at these altitudes. With that said I compare that line to the RWD ROC in the next graph.
As you can see the in-game F6F-3 ROC looks nothing like the RWD ROC. That and the only altitude where the in-game ROC matches the RWD ROC is at 13,225ft. Below that point the in-game ROC is lower than the RWD ROC and above that point the in-game ROC is higher than the RWD ROC.
Since online sim performance tends to take place at 'mid' altitudes I like to show the percent error at ~15kft. As you can see the F6F-3 has a 5% better ROC than it should at 15kft. Which is 'much' lower than the 24% (RAD closed) to 26% (RAD open) better ROC the Bf-109K-4 1.80ata enjoys at 15kft.
Here is a link to the full analysis
4.08 F6F-3 Best ROC Supercharger Settings per Altitude