Spit IIa Performance graph

[Blackdog_kt]

Watch your language...

On the topic at hand, going fine pitch/high RPM while flying in low-density air decreases performance after a certain point. The air is "thin" so you need to coarsen the pitch (lower RPMs) to get a sufficient bite of air, otherwise the prop just spins around really fast without pushing the needed amount of airflow.

It's modeled the same way in 109s by the way (you get better performance if you drop your RPMs a bit at higher altitudes) and it's one of the first things i noticed and really liked in the sim.

[Seadog]

Originally Posted by Blackdog_kt

Watch your language...

On the topic at hand, going fine pitch/high RPM while flying in low-density air decreases performance after a certain point. The air is "thin" so you need to coarsen the pitch (lower RPMs) to get a sufficient bite of air, otherwise the prop just spins around really fast without pushing the needed amount of airflow.

It's modeled the same way in 109s by the way (you get better performance if you drop your RPMs a bit at higher altitudes) and it's one of the first things i noticed and really liked in the sim.

The engine cannot produce maximum power unless the supercharger is spinning at maximum speed to provide maximum boost. The effect of prop tip speed is practically unnoticable with BofB RAF fighters at RPMs of 3000 or less because the props were designed to provide full power at this RPM and were sized accordingly.

[CaptainDoggles]

I thought we decided that the atmosphere in game was way off the mark?

[bongodriver]

Originally Posted by CaptainDoggles

I thought we decided that the atmosphere in game was way off the mark?

Not completely, there is a setting on the FMB which brings the atmospheric temparatures in line with ISA, but by default it seems the atmosphere is modelled as ISA + 10 which is perfectly feasible in the real world in summer time, with ISA +10 we can expect to see an underperformance from what is stated in aircraft flight manuals, the results of my atmospheric tests are in the hurricane speed thread.

http://forum.1cpublishing.eu/showthread.php?t=32523

at some point I wan't to check the pressure lapse rate but I don't think it makes for as big an issue as temparature.

[CaptainDoggles]

Originally Posted by bongodriver

but by default it seems the atmosphere is modelled as ISA + 10 which is perfectly feasible in the real world in summer time

That might be a map-wise setting, hard-coded lke we used to see in 1946. Be interesting to test if/when BoM comes out.

[bongodriver]

Originally Posted by CaptainDoggles

That might be a map-wise setting, hard-coded lke we used to see in 1946. Be interesting to test if/when BoM comes out.

did you check that thread I mentioned? the Breeze/thermal factor slider in mission parameters in the FMB changes the temparatures and set it to 0 you get pretty much standard conditions, with further experimentation I'd like to find out if there is a way to get ISA - conditions.

[CaptainDoggles]

Originally Posted by bongodriver

did you check that thread I mentioned?

I did, yes.

What I meant was that, perhaps the slider in FMB allows us to change the pressure in the relative sense.

I.e. The difference between 0 and 10 on that slider might not produce ~ISA and ISA+10 on a different map, which is what I meant by "map-wise setting"

It will be nice in a couple of years to if/when we get some FMB documentation.

[=AN=Felipe]

Good afternoon gents

so, takeoff weight = maximun takeoff weight

Temperature and pressure default, default settings and weather...

Climb speeds at 160mph @2600rpm - full throtle - better setting to climb.

Tests under 115ºC water temp. oil temp under 95º - maximun ºC permited under emergency purpose.

[bongodriver]

Temperature and pressure default, default settings and weather...

Actually if you want a good comparisson to the flight manual data then it would be worth creating a quick mission with a parameter changed which brings atmosphere to standard, look for Breeze/Thermal factor in the mission parameters in FMB and set it to 0, if the performance is off under those conditions then we know there is a problem.

[Crumpp]

Originally Posted by Blackdog_kt

Watch your language...

On the topic at hand, going fine pitch/high RPM while flying in low-density air decreases performance after a certain point. The air is "thin" so you need to coarsen the pitch (lower RPMs) to get a sufficient bite of air, otherwise the prop just spins around really fast without pushing the needed amount of airflow.

It's modeled the same way in 109s by the way (you get better performance if you drop your RPMs a bit at higher altitudes) and it's one of the first things i noticed and really liked in the sim.

That is one of the details I really like about the sim too.

The best thing is the mindset it forces upon a player. You have to keep a scan going even during a dogfight and above all "fly the plane". That fact alone makes it a better simulation than anything to date.