This topic covers the early versions of the Mustang, which includes the P-51-1 (Mustang MkI/MkIA) and the P-51A (Mustang MkII). However, both planes, the Mustang MkI/MkIA and the P-51A, seem to have the same FM with the only difference being the Armament and external loads. I believe it would be good to get the Mustang MkI/MkIA FM revised (lowered) to give it a more accurate performance envelope.
Two different versions of the Allison V-12 engine were used in the early mustangs and therefore had different performance envelopes. The Mustang MkI/MkIA used the V-1710-39 and the P-51A used the more powerful V-1710-81. This is not properly modeled in the game, both are using the V-1710-81 engine as both of them indicate a war emergency boost of 56-57 inches of manifold pressure which is correct for the V-1710-81, but the V-1710-39 was rated at 44.5 inches of manifold pressure which was less powerful.
Greybeard, with help from CWatson, developed a new FM for the Mustang MkI/MkIA. I tested the new FM and got very satisfactory results. The new FM worked fine in 412.2 with modact 5.30 using the QMB. I had been using the QMB to test the Mustang MkI against four A6M2-21s. I had been able to be successful in every encounter and I felt like I was completely in control of the combat. I almost always was able to get them all, but a few times one or two got away when I ran out of ammo. I tried this scenario with either the P-40E or P-39D and usually was shot down. The best I could do was run away with the P-40E, but a few times with the P-39D I was able to get a Zero and still get away.
Using this new FM significantly changed the situation and I now had to use very restricted rules during the engagement (very little turning anywhere near the Zero’s). I’ve only flown this scenario four times and I have been much less successful than before. I had never shot down more than two of them and I was even shot down once (the first time). This new FM greatly reduced my speed advantage, but more significantly reduced the Mustang's acceleration and made it extremely hard to get away from the Zero’s after any turn unless I could dive. Even with the new FM the Mustang was noticeably superior to the P-39D when combating the Zero.
The new FM is available at Greybeard’s website using the URL below:
http://greybeard.xoom.it/virgiliowizard/il2-cornerThe freeil2modding topic with much more information can be found at:
http://freeil2modding.free-forum.net/p-51a-flight-model-vt2340.htmlI really appreciate the efforts of Greybeard and CWatson to make this correction a reality.
Thanks tooslow
P.S. Food for thought!!
As a side note the V-1710-87 used in the A-36A was rated at 52 inches of manifold pressure. Of course each these engines have different critical altitudes with the -87 engine being the lowest. It might even be interesting to make a sort of franken A-36A using the V-1710-87 engine (with a new FM) and the P-51A with the two nose guns from the MkI added to the armament … It would appear that the main item missing would be the dive brakes that could be added at a later date.
When there was a specific P-51 website (
http://p51sig.ipbfree.com), which is no longer active, I remember them having a short series, with photographs, that showed that the nose guns from the Mustang MkI and A-36A could easily have been added to the P-51A (and the Mustang MkIA) to increase it’s fire power. They also noted that there was plenty of room for much more than the 200 rpg that the A-36A carried. It was unclear how this additional weight would affect the performance and the CG of the aircraft.
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Topic: Aviator Mod Team - Early Mustangs V2 (Read 68008 times)
