Thanks for the 190 docs, I hadn't seen most of those before.
The altitudes the FW-190A3 had advantages over the Spitfire Mk IX Merlin 61 (+15) are pretty much the same ones the FW-190A8 has over the Merlin 66 (+25).
Based on the figures you've linked to, the Spit IX on 25 lbs will have a speed advantage at all altitudes.
Bear in mind JL 165 was running extremely poorly when the A&AEE got their hands on it, it had already been used for extensive tests by RR.
Here's a graph showing the performance the A&AEE estimated for JL 165 at 18lbs, compared to other tested Spits at 18lbs:
The 190's weight and level acceleration advantage would leave it behind.
I don't believe the 190 had a level acceleration advantage under most circumstances.
The AFDU found no advantage for the 190 except at altitudes where it had a speed advantage. That's against a Spit F IX, with much lower horsepower, and a much worse climb rate, than the Spit LF IX.
When you'[re talking about a Spit LF IX at 25 lbs, you have no weight gain, and up to 500 hp more than the plane tested against Faber's 190.
The 190's weight and level acceleration advantage would leave it behind. If the 190 kept his dive at those altitudes the Spit would eventually catch him.
According to the Spit pilot in the test against Faber's 190, the Spit would begin to catch the 190 after a dive of 3000 ft.
This is also why the 190 a much higher dive speed in the thicker lower atmosphere.
The Spitfire was limited because of iupfloat of the ailerons, nothing to do with drag per se.
The Spit XIV Griffin 65 was able to dominate the 190A. The horsepower gains of the Griffon 65 were not that phenomenal over the Merlin 66 (+25)
At lower altitudes, the Merlin at 25 lbs actually put out more horsepower than the Griffon at 18 lbs. And that in an airframe with no extra weight.
However the weight gain and keeping a similar Power to Weight ratio of the Spitfire XIV gave it the inertia to overcome the induced drag and catch the 190A in the zoom.
Extra weight isn't really an advantage for a fighter. It would be quite easy to make any WW2 fighter heavier with the addition of extra armour, for example, but the work all went the other way, on keeping them as light as possible.
You might lose in zooms and dives, but you gain in level acceleration, climb rate, turn rate, low speed handling, and increased g limits.
The Spit LF IX with 25 lbs boost would dominate any of the 190s up to the A9 at most altitudes. I can quarantee that you won't see a Spit at 25 lbs unless it's a highly priced perk.
I think the RAF will need the Spitfire Mk IX Merlin 66 (+25) in Tour of Duty.
I'd be very suprised if the RAF gets anything more than a Merlin66 at 18 lbs in tour of duty, unless it's to combat the very late war aircraft like the Dora and 109 G10/K4.
Mind you, I don't know how they are going to manage perks/limited availability in ToD. But I don't expect to see the Merlin 66 at 25lbs up against the 190A in anything like similar numbers.
