Why does a stock P-51 outperform the Racer at similar power settings?

[Guest]

I tested both climb performance and level speed at 67" and 3,000 rpm in the shockwave P-51D, and the MS P-51 Racer. The stock outperformed the racer in both cases. Why is this?I can understand the clipped wings would reduce lift, therefore reducing climb performance, but I can't understand how its slower in level flight, given all the aerodynamic improvements. With the settings above the stock mustang was climbing at just over 4,000fpm, and the racer at just over 3,000fpm, though it was a bit hard to measure being as unstable as it is.In level flight at 8,000 feet the stock mustang was doing 350mph, while the racer was only doing 300mph. A 50mph difference is quite significant, as it takes a great deal more power to add 50mph to 300mph aircraft.

[Guest fsxmissionguy]

I wonder what Paul Lange has to say about this post?Paul?My question would be ... how do both models compare to the actual P51 that the MS version was modeled on?

[Guest]

I don't know much about the way engine power is modeled in FS, but perhaps it has to do with that? If its just a linear scale from 0%-100% I can see where a given MP would not correspond to correct power output, but I really have no idea.

[jmig 100]

>I wonder what Paul Lange has to say about this post?>>Paul?>>My question would be ... how do both models compare to the>actual P51 that the MS version was modeled on?I don't know about the P-51 Acceleration did. I do know that Shockwave Productions have an almost anal obsession to get their planes as close to real as possible. I own the P-51, P-40 and Me-109. Can't talk about the Me-109 but, with both the P-51 & P-40 Shockwave had actual certified pilots of those planes involved with the development. I would say they are right on the numbers as far as performance goes.

[Guest Roymcm]

I don't have the shockwave P-51, so I can not comment on the veracity of its performance. But I think the common misconception is that MS attempts to model aircraft with 100% fidelity. This is simply not the case. Sure, they try to get the numbers as close as possible to reality, but representative performance is the goal, not a perfect match with the real life numbers, which are often not real in themselves, particularly when talking about WWII aircraft.It

[P-12C 0]

The engine modeling on the Racing P-51 in Acceleration is pretty good but differs significantly from a stock Mustang and how we modeled engines before Acceleration.The Racer has a single stage "dash 9" supercharger which can put out more boost than the stock two stage supercharger in a stock Mustang, but at altitude, we still only have one stage, so it will fall off on power as the altitude increases.The reason the Racing Mustang can produce so much power is also because the aircraft are modified to have much higher RPM's so winding it up to 3450 or 3500 RPM produces a lot more boost as the supercharger is spinning that much faster. If the prop is pulled back to stock limits, it won't be producing nearly as much boost as when racing.Lastly we tuned the aircraft's speed envelope to match real-world best-performance race speeds. In talking with the owners of Cloud Dancer and Miss America, we did good with the top speeds on the Reno course, but don't have enough speed at cruise and don't accelerate fast enough on the takeoff run. Unfortunately we received this information too late in the development cycle to tweak it.I am a fan of the ** flight models so I don't doubt their's is accurate throughout the normal flight envelope. I have talked to Mustang pilots that said a warbird Mustang will have zero chance of hitting book speeds in level flight and would have to be in a dive to hit those speeds, so that should be a consideration as well.

[Guest]

Thats quite insightful. Thank you very much! :)