• January 26, 2020, 05:41:14 PM
• Welcome, Guest

Pages: [1] 2   Go Down

0 Members and 1 Guest are viewing this topic.

• member
• Offline
• Posts: 54
##### P51D with 100/150 grade fuel
« on: October 10, 2015, 09:37:39 AM »

To the best of my knowledge all of our 'Stangs are limited to 67" Hg due to boost limitations imposed by 100/130 grade fuel and by late '44 the 8th AF was operating almost solely on the higher octane fuel at 75" Hg.  So, is there any chance one of you talented lot could perhaps tweak our current D-20NA to reflect late war fuel?
Logged

#### SAS~Tom2

• SAS Honourable Member
• member
• Offline
• Posts: 7955
• no sweat
##### Re: P51D with 100/150 grade fuel
« Reply #1 on: October 10, 2015, 05:28:15 PM »

Hi and welcome!
That is not exactly a proper request.

Try to add a few more references e.g. to undermine your request.

Cheers

Thorsten
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #2 on: October 12, 2015, 07:45:34 AM »

OK, sorry about that, let's try this again.  In game our P-51s are limited to 67" Hg but in reality the P-51 (in the hands of the 8th Air Force) was running only 100/150 grade fuel by July 1944 which increased MP to 75" Hg and, according to http://www.wwiiaircraftperformance.org/150grade/150-grade-fuel.html.....

Code: [Select]
Operation of the airplane at 75 in. Hg. manifold pressure in low blower increased speed in level flight 16 MPH over the high speed at 67 in. Hg. manifold pressure at altitudes from sea level to 7400 ft. A 14 MPH increase was obtained at altitudes from 16,000 ft. to 20,800 ft. in high blower.
Code: [Select]
The rate of climb was increased 560 ft/min. from sea level to 2,200 ft. by 75 in. Hg. manifold pressure operation. At 15,700 ft. in high blower the rate of climb was increased 580 ft/min.
Code: [Select]
From sea level to 10,000 ft. in low blower the 1650-7 engine gave increases in speed from 2 to 11 MPH over the 1650-3 engine. From 16,600 ft. to 24,000 ft. in low blower the 1650-3 engine was approximately 20 MPH faster than the 1650-7 engine. In high blower from 18,000 to 24,200 ft. the 1650-7 gave an increase in speed of approximately 10 MPH but at 29,200 ft. the 1650-3 engine was 6 mph faster. This increase of the 1650-3 engine over the 1650-7 engine should continue at altitudes above 29,200 ft. as is shown in Fig. 8 by the dash line. Due to malfunctioning of the carburetor, however, speeds of the 1650-3 fell off above this altitude and were as much as 12 miles slower than those obtained with the 1650-7 engine.

This is a pretty significant increase in performance and though I feel that the Pony already matches up well enough with the 109K-4 and 190D-9, we just don't have the historically correct option for fuel which, admittedly, will only help out Mustang drivers like myself!  I have included no pictures because, well, we already have some fine P-51 models and this will only require a FM tweak to model the performance gains.
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #3 on: October 16, 2015, 05:34:32 PM »

Some additional data on the subject from the website http://www.spitfireperformance.com/mustang/mustangtest.html....

Using 44-1 (100/150 grade) fuel the Mustang saw low blower climb figures increase to 4650-4670 fpm at 3500 feet at 75" Hg, 4300-4370 fpm at 6500 feet at 67" Hg, and 3830-3950 fpm at 9000 feet in low blower at 61" Hg.  In high blower the figures are 3650-3680 fpm at 17,800 feet and 75" Hg, 3440-3490 fpm at 19,000 feet and 67" Hg, 3030-3060 fpm at 22,000 feet and 61" Hg.

Again, these are pretty significant performance gains and not only is this performance historically verified, it was THE norm for the 8th Air Force.  When P-51 drivers like myself are fighting K-4s and D-9s, we should be doing it with this fuel and these numbers.
Logged

#### BaronFel181

• member
• Offline
• Posts: 159
##### Re: P51D with 100/150 grade fuel
« Reply #4 on: October 16, 2015, 06:31:49 PM »

I'm pretty sure that the Mod P-51D-30NA and F-51D-30NA are modelled at 75" Hg. They've been around for years.
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #5 on: October 17, 2015, 09:37:52 AM »

I just dl'ed the AAA D-25 and D-30 and the performance is awesome!  I haven't tested to see if the figures line up to reality yet, but I have a feeling it's going to be close.  My only complaint is that the auto radiator doesn't work anymore.  Was that ever addressed or am I just going to have to pretend that my crew chief can't fix the control valve?

EDIT - My supercharger is no longer automatic either....
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #6 on: October 19, 2015, 07:03:59 AM »

OK, I feel like I'm simply talking to myself in here, but here goes;  I really like the performance of the P-51D-30 from the AAA pack I downloaded but it's not what I want because when I fly a P-51 I enjoy not having to worry about making sure my supercharger is in the correct stage and my radiator is in the correct position.  I do this when I fly just about all of the rest of my preferred Allied aircraft and I enjoy NOT having to do that with the Pony.  If there is an existing P-51D at 75" Hg with a properly modeled radiator and supercharger then please point the way and if there isn't, then I'd be much obliged if one of you badasses made it happen!
Logged

#### OberstDanjeje

• member
• Offline
• Posts: 1393
##### Re: P51D with 100/150 grade fuel
« Reply #7 on: October 19, 2015, 07:50:56 AM »

I'm sure there is a D25/30 in DBW and CUP modelled with high grade fuel.
The AAA version are old and build for 4.09
Which game version are you using?
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #8 on: October 19, 2015, 08:19:26 AM »

I'm running C.U.P. but it only had the Mustang family up to the D-20.  I had to download the AAA Stangs because they were the only ones I could find that looked like what BaronFel was talking about.
Logged

#### OberstDanjeje

• member
• Offline
• Posts: 1393
##### Re: P51D with 100/150 grade fuel
« Reply #9 on: October 19, 2015, 09:22:44 AM »

I don't use CUP
try adding this line, it should work, if not do you have the jet era module too?

P-51D-20NT        air.P_51D20NT 1                               usa01 SUMMER
P-51D-25NA        air.P_51D25NA 1                               usa01 SUMMER
P-51D-30NA        air.P_51D30NA 1                               usa01 SUMMER
F-51D-30NA        air.F_51D30NA 1                               usa01 SUMMER

remove the AAA files
Logged

• member
• Offline
• Posts: 54
##### Re: P51D with 100/150 grade fuel
« Reply #10 on: October 19, 2015, 02:21:41 PM »

I removed the AAA files from my #WAW folder, removed the old .air lines, and pasted in the new ones and now I get this;

Code: [Select]
FM called 'FlightModels/P-51D-20.fmd' is being loaded from Alternative File: 'gui/game/buttons'[8:17:23 PM] Main begin: PlMisAir: class 'air.P_51D25NA' not found[8:17:23 PM] java.lang.RuntimeException: PlMisAir: class 'air.P_51D25NA' not found[8:17:23 PM] at com.maddox.il2.gui.GUIQuick.fillArrayPlanes(GUIQuick.java:1064)[8:17:23 PM] at com.maddox.il2.gui.GUIQuick.<init>(GUIQuick.java:1841)[8:17:23 PM] at com.maddox.il2.gui.GUI.create(GUI.java:160)[8:17:23 PM] at com.maddox.il2.game.Main3D.beginApp(Main3D.java:1885)[8:17:23 PM] at com.maddox.il2.game.Main3D.beginApp(Main3D.java:1579)[8:17:23 PM] at com.maddox.il2.game.MainWin3D.beginApp(MainWin3D.java:212)[8:17:23 PM] at com.maddox.il2.game.Main.exec(Main.java:432)[8:17:23 PM] at com.maddox.il2.game.GameWin3D.main(GameWin3D.java:235)[Oct 19, 2015 8:17:23 PM] -------------- END log session -------------
And yes, I do have the jet era module.
Logged