[Viper2000]

Originally Posted by IvanK

The Engine instruments in game are animations that "represent" engine performance. This is separate to the actual achieved performance by careful flight test. In addition it was at the time standard to have only +8Lb Boost guage even though the Merlin XII was using +9lbs regularly, the same goes for use of Boost Cutout. In this case if below the +12Lbs FTH then all you are going to see is full scale Boost deflection.

The flight testing I have done indicates the Spit MKII is actually performing pretty close to the real world numbers, though Boost figures are obviously wrong, but recall these are animations so easily fixed. So I agree with ICDP it represents +12lb performance.

MKII, CEM On , Overheat off, 100% Fuel, Max throttle, RPM Full fine 3000 controlling
Climb Speed 160-165MPH as per RAE Climb test RAE Figures in [ ], ROTOL CS

0-5000ft 1:42min, Boost +5.5 [1:42]
0-1000ft 3:23min, Boost +5.5 [3:24]
0-15000ft 4:58min, Boost +5.0 [5:00]
0-18000ft 6:09min, Boost +2.5 [6:06]

In Game FTH is around 14,500ft
Vmax in game 280MPH IAS, 358TAS , [350TAS]
Vmax Sea Level 280MPH IAS [290]

Climb methodology used:
Start at Sea level about 30MPH below desired climb speed.
Select Power and Prop as required
About 15MPH below desired climb speed smoothly pitch to the required attitude and start the clock
Spedd held +-5mph to the schedule.

A few points:

1. We shouldn't need to disable overheat to match performance figures without engine failure; I'm pretty certain that all the actual flight tests we're using for reference were conducted 100% Full Switch .
2. FTH is a function of TAS due to intake ram; you'll get a higher FTH during a level speed run than when climbing at Vy. Even so, I'm somewhat surprised that the FTH for +5.5 psi is that low at 3000 rpm.
3. Do your figures include PEC? There's no mention of it in the sim manual, so I am unsure whether the ASI gives true IAS, or whether we actually have something else like CAS or EAS...
4. Is there any news on the various high altitude difficulties people are reporting? I flew a 109 for the first time today and found that it also runs into engine trouble if you try to climb; I know the devs want us to see the pretty buildings, grass, forests and roads, but killing engines as punishment for climbing is taking things a little far!