& add also the extra 10% in take-off power by using the 'wet' cheat..
Well, actually, if you want me to do it that way (which is more work and not as conservative as I've already done):
Thrust is approximately proportional to power, and F = m * a, so 10% more thrust is 10% more acceleration (i.e., a_wep = 1.1 * a_nowep). (F = m* a is a rough approximation not including drag, but including drag won't matter since the time difference below is already so low as to not matter.)
dv/dt = a, so v = a * t, and t = v / a. Takeoff and wheels up is determined by when you hit takeoff speed (with distance and time depending on when you reach the appropriate speed). In other words, t_wheelsup = v_wheelsup / a.
Without wep, t_wheelsupnowep = v_wheelsup / a_nowep.
With wep, t_wheelsupwep = v_wheelsup / a_wep.
Thus, t_wheelsupnowep / t_wheelsupwep = a_wep / a_nowep = 1.1
We have an airshow Bearcat with t_wheelsup = 14 seconds. Let's look at both ends of a way to estimate our standard Bearcat. If the airshow Bearcat is like a standard Bearcat (with armor, ammo, 50% fuel) and no WEP, then t_wheelsupnowep = 14 seconds, and t_wheelsupwep = 14 / 1.1 = 13 seconds. If the airshow Bearcat is like a standard Bearcat and full WEP, then t_wheelsupwep = 14, and t_wheelsupnowep = 14 * 1.1 = 15 seconds.
So, what is the difference in time between using WEP until wheels up and not using WEP until wheels up? In one case it is 14 - 13 (1 second), and in the other case it is 15 - 14 (1 second). In either case, the difference is 1 second.
That is even far less than my huge overestimate of 7 seconds.
