When combat was imminent, you immediately went to either METO or Max power if necessary. At times when one's life was in danger you used as much power as you could get. At METO power the P-40B's speed would be above 300 mph, and at these speeds, unless the enemy had an altitude advantage, he could not even catch you.
Robert Scott tells the story about escaping from a Japanese fighter. Not being high enough to dive, he says he was pulling 55 escaping from a Japanese fighter. (41 in hg was T/O M/P) He thought he heard the engine detonating, and reduced power. When the sound he heard turned out to be exploding cannon, he immediately went back to 55 in MP. Needless to say he escaped.
First and formost is a fact often overlook by many, which was the Flying Tigers only attack IF they had the advantage. (Altitude or speed.)
We used to liten to Tokyo Rose quite frequently. On several of her broadcast, she called the Flying Tigers cowards because we refused to stay and fight, then challanged us to stop running away. We thought this was quite humurous, and at the same time, knew our tactics were hurting.
Also on some of Tokyo Rose's broadcasts, the number of AVG aircraft that the Japanese claimed to have shot down, was the exact number Japaese aircraft that we had destroyed. (We only lost 4 pilots in aerial combat.) This was the figure I used in giving our kill ratios. It had no bearing on the number of aircraft we or they destroy. Even [Dan] Ford has said that we killed approximately 400 air crew.
To show a couple examples of attacking enemy fighters: If you attack head on, which the enemy was reluctant to do, because our guns outranged the fighters, they would normally pull up. (If he started turning away, he would already be at a disadvantage.) You started firing at Max range, and then dive away, under these conditions we didn't turn and tangle with a Jap fighters.
Attacking the enemy from a 3 to 6 o'clock position.
Why roll rate was important, is that one must remember that all maneuvers, except for a loop, started with a roll. The slower the roll rate the longer it took before the turn began.
1. If he turned away, he set you up on his six. A most undesirable position for him, because he would be a dead duck.
2. The enemy invariably turned toward you which was normal and anticipated. With his slower roll rate, you could beat him into the turn, get a deflection shot at him, and when you slowed down to where he started gaining on you in the circle, you rolled and dove away before you were in his sights. If you haven't tried it don't knock it.
This is where roll rate came into the picture. As far as Japanese fighters were concerned, their inferior roll rate was at all speeds. Above 240, it would take the Zero 3 second before he attained bank angle for max turn. (And the airplane doesn't start turning until bank angle is established.)
Since you could see him starting to bank, which you would have anticipated, you could easily bank more quickly and establish max bank angle within 1 second, and pull whatever "Gs" necessary to establish lead.
At this speed, and with your lead already established, you could maintain lead for some time before speed bled off to where the Zero could turn inside, you got the hell out. (Don't forget same speed and same "G" equal same radius of turn. Above 220 IAS the radius of the circle was determined by pilots ability to withstand "Gs." You could turn with the Zero as long as the speed was above 220 IAS.
If his reaction was only to pull. At these speed the "G" factor still applies, beside the Zero could not take 6 "Gs," and the P-40 could pull over 9 "Gs." Most fighter pilots could "momentarily" withstand 9 "G's" or more without blacking out.
If the situation was reversed and the Zero was attacking you. Your roll rate would save your ass by allowing you to roll to max turning bank, use 6 "Gs" or more, then continue rolling to inverted and dive. Rolling 180 degrees to dive would take less than 2 seconds, the Zero took 6. The Zero would never get a shot. He couldn't get lead, and by the time he was inverted you would already be out of range, gaining speed much more rapidly than the Zero.
As can be seen from the above illustration, that in the beginning roll rate was the primary factor in starting any maneuver except the loop. After bank angle was established then speed was the primary factor. To escape from a zero, roll rate again became the primary factor then speed.
Anyone who disagrees with the above has never been in combat, and as far as I know, few books if any bring this out.