Just one thing... why are you keeping engine on max power after final speed is achieved?

I'am very confused with that. There is no point on throwing energy away, you will actually be charging the system, instead of increasing speed.

The big problem with any propeller is it's final speed. You could still accelerate, because your frame is damn good, but the propeller is a huge hindrance at high speeds. Also, keeping the throttle at full power at 900Km/h seems preposterous!

If you keep your engine at max power until the end of a dive, I will tell you that if there is a bug, it is with the planes that won't overheat, and they all should get engine damage. Check the RPM's of both planes and see the difference, but I doubt you will gain nothing by keeping the throttle at max power to the end of the dive.

I'll try and do this in the next couple of days... see what my results are doing this exactly. See what we might come up with collectively.

Sorry RPS69, what do you mean by "final speed?"

I'm pushing the throttle as long as I can because the enemy behind me is likely doing the same. The engine and propeller may be very inefficient at those speeds, but I need to squeeze out every last km/h and fly faster than the La-7 can dive, and as long as the engine doesn't cook then throttle to the wall is the way to do it. Reducing prop pitch may give me more speed at those extremes, and that's where the automatic systems in the German planes work very well, except apparently in the 190-D9 1945.

Check engine RPM´s.

Compare it with the other 190D9 model.

What I mean, is that there is a point that the plane speed on a dive is beyond the engine+propeller efficiency. You are not squeezing more speed, you are reducing it. To achieve more speed, you need to feather the prop.

Also, stabilizing the plane at the end of the dive should be much more difficult with a high reved engine, than with a moderating one. High revs generates a huge gyro effect, who will increase resistance to vector change.

To report this as a bug, it will be better to check planes RPM, and the clock who shows the prop pitch. If both planes show the same behaviour here, then I would look for how much overreving you are applying, but I would expect every plane to seize it´s engine after that kind of mistreatment.

If you are trying to find a bug (or a non-bug, jusk like RPS69 said), thats ok.
But regarding the engine management (at lest in game), in a very steep dive just like the ones refered here, you only have to profit by using manual prop-pitch. Over-reving doesnt only mean overheating, but also means loss of power. When the manuals refer the best power RPM it means below that RPM you have less power, and above that RPM you have also less power.
Beside that (at least in real aircraft) the blades turning very fast smash the air instead of mooving the air away properly. (Someone correct if i said something wrong- Not expert.)

I remember on a spanish server, (gRiJ), once after everybody left, we stud only 3, and instead of dogfighting we went for the "airshow" manouvers, follow the lider, smokes etc. We were chasing this spanish "gRiJ Torero", we all in bf109, and after the third dive i heard my friend engine go dead! (he was just on my side) Then i asked: No manual Prop-pitch? He was on auto. He never used manual.

If you dont have one extra axis lever for prop-pitch (witch is very intuitive to use), and if you are using keys, remember that you can adjust that prop pitch value before changing it to manual.
Most times people change it straight on the 100% mark, and the engine imidiatly over-revs! If you use a key to +pitch, other to -pitch, click e.g. 8 or 9 times the -pitch key, before you pass to manual. If you have lots of speed and throttle on, press more times, than, after passing to manual, check RPM, and adjust if necessary. When you start climbing get ready to adjust again, or pass to auto prop-pitch again. Here you must anticipate, or you will lose precious RPM. The value of manual pitch will stay exacly where you left it when you passed to auto.

I know most people sure knows this, but hope someone will learn from here. Thank you people.

WOW, i just tried now on the FW190 D9, 1944, Airstart from 5000 meters. It is a huge diference, from manual to auto. On manual it only slightly over-revs, and you get a LOT more speed. With auto it seems just like you have flaps on, LOL, and the RPM gauge goes like 3500 plus. (this causes overheat)

I gave 910km/h on manual and was able to pull ok. Just set prop-pitch to 0% before you dive. Dont forget to trim nose heavy. Throttle back before crash.

This D9 does not have prop-pitch indicator gauge?

That definitely makes sense and it's what I do when I'm in planes without auto prop-pitch, I assumed the automatic mechanisms in the German planes would do this more efficiently for me.

In a previous post you were wondering why I keep the engine at maximum power and you seemed to imply that reducing power would somehow generate more speed, I'm guessing you meant prop-pitch, not power?

This makes sense too, and thanks for the advice about pre-setting the pitch before switching to manual.

I still don't get why the D9 1945's engine can be so easily wrecked while the D9 1944 or the Ta 152 H will only overheat in a steep dive. If that's the way it was and it's an accurate feature then great, it's more interesting and we can take steps to avoid the problem. Otherwise it might be a bug. I'll try comparing the rpm in a dive in a D9 44 and a D9 45 later today.

I mean both. You should achieve the same speed, without the need to overheat the engine. Engine power should be maxed when starting the dive, but after some point, plane dependent, power should be diminished to around 30%, and pitch to a minimum.

Hmm, I don't think I can agree with reducing power to go faster, that seems very illogical. Reducing pitch when you exceed the planes maximum level speed at a given velocity, sure, but power?