Acceleration comparisons

[IceFire]

Originally Posted by MaxGunz

Those are the ones in IL2Compare 4.07m, the last IL2C I have.

There's a 4.11 IL2 Compare kicking around. Haven't seen a 4.12 yet...

[Monty_Thrud]

Originally Posted by IceFire

There's a 4.11 IL2 Compare kicking around. Haven't seen a 4.12 yet...

http://forum.1cpublishing.eu/showthread.php?t=29744

Scroll down for 4.11

[MaxGunz]

I've had IL2C 4.11 and 4.07m for a while it turns out, just only a shortcut to 4.07m on the desktop. 4.07m version is off now, 4.11 link in place and holy cow now I see the confusion! I forgot about the rabbit Spitfire versions and now I have to wonder why is there no P-51D with empty fuselage tank and CoG to match? Then we could hear a new verse or chorus to 'stang-whining based upon stick forces too high.

[pandacat]

It's quite interesting to see post-510kph, 2700rpm actually accelerates faster than 3000rpm for p51c. Btw, do you have similar data on P51Ds? 5nt and 20na. I would expect slightly worse performance. Also, it's surprising to see 109G series has slower acceleration than mustangs given 109 has higher power to mass ratio.

[MaxGunz]

Consider how CSP's work in the case of the P-51.

[pandacat]

Originally Posted by MaxGunz

Consider how CSP's work in the case of the P-51.

But doesn't everybody else have CSP, too? Spit, 109, 190? Or P51's CSP is somewhat special? For spit and 109, it seems from the charts that 3000rpm always accelerates faster than 2700rpm

[MaxGunz]

At what speed and altitude? Compare the whole Ps graphs.

Consider the drag as size and coefficient, P-51 is bigger.

Where is the supercharger working best compared to the alt?

The speed of the plane has much to do with the optimal blade angle but mostly...

When you command more prop rpm than the plane has power to support, the prop will flatten a bit and you'll lose some thrust.

Most IL2 planes have some form of pilot-controlled CSP and some are even more automated though there are pre and early war models that don't have CSP all the way down to fixed props.

[horseback]

Originally Posted by pandacat

But doesn't everybody else have CSP, too? Spit, 109, 190? Or P51's CSP is somewhat special? For spit and 109, it seems from the charts that 3000rpm always accelerates faster than 2700rpm

Mustang's throttle is supposed to control manifold pressure directly, rather than just the amount of fuel going to the engine,as in other types. During the 10k tests, I ran the Spit IX LF at 2700 and 3000 rpm to see if there was a difference, and 3000 rpm was always superior at all speeds.

The Mustang is a bit different. If you look at the 10k charts, there is a point at which the Mustang at 2700 rpm will accelerate more quickly than at 3000rpm, and it reaches top speed much sooner after the three or so earlier 10 kph intervals. In the thicker air at 100 meters, this doesn't seem to happen, or at least it isn't as obvious.

Currently building my 5k database, which will probably show a transitional difference somewhat less than the 10k tests for the Mustang at 2700 vs 3000rpm; it will probably be more pronounced at 15k and 25k.

cheers

horseback