Speed graphs for Spitfire and Hurricane

[Triggaaar]

Originally Posted by BlackSix

Speed graphs for Spitfire

Given that most fighting tends to happen below 6,000m, the current game is closer to the flight tests than the patch.

[Insuber]

Originally Posted by camber

It's hard without knowing how the devs have configured their flight model formulae, but it seems likely to be as you say. Of course coding in this way makes it hard to calibrate to exact speed vs altitude (or any other) profile, as max speed (i.e where accelleration = 0) is at the termination of a chain of calculations where changes along the chain (to constants or altering the formulae themselves) can have unpredictable effects, and it may come down to laborious trial and error getting the two curves to match. Of course just getting the speed vs altitude curve right does not mean sim fidelity, for example if the plane accellerates in a non historical way to get there.

But we can compare along the chain where there is historical data, and currently boost is kind of right but the final speeds are wrong.

There are some problems with boost though, last night looking at the offline with cockpit off (apologies, I'm sure similar data has cropped up in many other threads):

Spits and Hurris have a boost controller (red cutout "off") that gives +5 1/4 to +5 1/2 psi minus boost cutout at 3000rpm full throttle. Boost drops as soon as the throttle is retarded, so CoD model is closest to the "variable datum" type of boost controller for all RAF aircraft. This should be +6 1/4 psi though.

Oddly, CoD boost increases to about right (+6.2 psi) when rpm is decreased to the 2600-2800 rpm range. From my reading this is incorrect, the boost controller should not be rpm dependant.

The Spit II with boost cutout activated (sea level; full throttle) achieves +9psi at 2600 rpm, +8psi at 3000 rpm (again the rpm-boost quirk). So the CoD Spit II acts most like a 100 octane conversion where the cutout was modified for +9 instead of +12 psi. At 3000rpm, the engine makes some distressed noises/ vibration but does not fail. Dropping rpm to 2600 rpm and/or putting mixture to weak smooths the engine. At sea level, boost cutout on, rad half open, weak mixture, 2600 rpm and +9 psi boost I could maintain 320 mph (IAS and TAS) for a full sortie. That is some serious speed (512 kmh)

The CoD Spit Ia/Hurri act (in boost characteristics) like 100 octane conversions where someone drilled the wrong size holes in error and gave tiny increments in boost. You can see the boost cutout effect in Hurri at 2600 rpm if you turn it off and on and watch the boost gauge(+6.2 to +6.4 psi), alhough I could not detect a speed difference. So you can't tell if the virtual tanks have 87 or 100 octane in them, it doesn't matter because the boost never gets high enough.

But getting the boost behaviour exactly right doesn't help much if the model does not pass the next check..that the boost combined with other inputs ends up producing overall performance in line with historical norms...which is more of a problem.

I didn't realise the Spit II could sit on 320 mph. Had an online sortie on ATAG, I just zigzagged up and down the channel on the wavetops at 320 mph, and started bouncing people from below. Fun, but not very historical I guess

camber

Good work camber, thank you. FM's are a complete mess today, but the team is working on that. Let's hope that the final result is better than what we have now, with uber Spit II and Hurricane, and poor G.50 crippled to complete uselessness.

Cheers!

[II/JG54_Emil]

Originally Posted by ATAG_Snapper

What....the UBER - G50???? LOL

ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜberÜber ÜberÜberÜberÜberÜberÜberÜberÜberÜber

???

What are you guys talking and complaining about?

I can´t hear all this complaining anymore.

[Robo.]

Originally Posted by II/JG54_Emil

???

What are you guys talking and complaining about?

I can´t hear all this complaining anymore.

Emil that was actually a joke about G.50... Good one btw.

[II/JG54_Emil]

Originally Posted by Osprey

I removed the BS so we can be clear about your position.

If you are trying to say that his arguments are foul because he does fly blue, then the same applies to red pilots.

Ergo, nobody flying red or blue only may argue.

I don´t think you want to say that, do you?

[335th_GRAthos]

We all took a concious decision, to have 1C concentrate their ressources to make a better graphics model.
It is therefore beyond doubt that we will have to wait for the graphics model to get finalised and afterwards, the long, hard discussion about the flight models will start.

I have always avoided discussions because speed is only one parameter; There is a lot more which plays a role in a dogfight.

What I would really like to see is that somebody downloads the CoD plane parameters and creates an IL2Compare like we had for IL2!





If we have that, we will have the required transparency to start discussions.

As I had commented in the improvements thread months ago, watching the "wing load" responsiveness of the airplanes (can be seen by the planes flying reasonably well with half-wing sawn off) makes me believe that, as far as the FM of COD is concerned, "speed" is one small piece of the puzzle.

~S~

[ATAG_Snapper]

Originally Posted by Robo.

Emil that was actually a joke about G.50... Good one btw.

I think his "U's" with the two little dots over them are overmodelled........

[bongodriver]

Ubermodelled...

[Sutts]

Originally Posted by camber

It's hard without knowing how the devs have configured their flight model formulae, but it seems likely to be as you say. Of course coding in this way makes it hard to calibrate to exact speed vs altitude (or any other) profile, as max speed (i.e where accelleration = 0) is at the termination of a chain of calculations where changes along the chain (to constants or altering the formulae themselves) can have unpredictable effects, and it may come down to laborious trial and error getting the two curves to match. Of course just getting the speed vs altitude curve right does not mean sim fidelity, for example if the plane accellerates in a non historical way to get there.

But we can compare along the chain where there is historical data, and currently boost is kind of right but the final speeds are wrong.

There are some problems with boost though, last night looking at the offline with cockpit off (apologies, I'm sure similar data has cropped up in many other threads):

Spits and Hurris have a boost controller (red cutout "off") that gives +5 1/4 to +5 1/2 psi minus boost cutout at 3000rpm full throttle. Boost drops as soon as the throttle is retarded, so CoD model is closest to the "variable datum" type of boost controller for all RAF aircraft. This should be +6 1/4 psi though.

Oddly, CoD boost increases to about right (+6.2 psi) when rpm is decreased to the 2600-2800 rpm range. From my reading this is incorrect, the boost controller should not be rpm dependant.

The Spit II with boost cutout activated (sea level; full throttle) achieves +9psi at 2600 rpm, +8psi at 3000 rpm (again the rpm-boost quirk). So the CoD Spit II acts most like a 100 octane conversion where the cutout was modified for +9 instead of +12 psi. At 3000rpm, the engine makes some distressed noises/ vibration but does not fail. Dropping rpm to 2600 rpm and/or putting mixture to weak smooths the engine. At sea level, boost cutout on, rad half open, weak mixture, 2600 rpm and +9 psi boost I could maintain 320 mph (IAS and TAS) for a full sortie. That is some serious speed (512 kmh)

The CoD Spit Ia/Hurri act (in boost characteristics) like 100 octane conversions where someone drilled the wrong size holes in error and gave tiny increments in boost. You can see the boost cutout effect in Hurri at 2600 rpm if you turn it off and on and watch the boost gauge(+6.2 to +6.4 psi), alhough I could not detect a speed difference. So you can't tell if the virtual tanks have 87 or 100 octane in them, it doesn't matter because the boost never gets high enough.

But getting the boost behaviour exactly right doesn't help much if the model does not pass the next check..that the boost combined with other inputs ends up producing overall performance in line with historical norms...which is more of a problem.

I didn't realise the Spit II could sit on 320 mph. Had an online sortie on ATAG, I just zigzagged up and down the channel on the wavetops at 320 mph, and started bouncing people from below. Fun, but not very historical I guess

camber

This is another problem with the engine model - switching to auto weak mixture at high boost settings should have quite the opposite affect, causing severe detonation and rapid engine damage. The manual states a maximum boost of 3 3/4 lb when using a weak mixture. These are 100 octane settings and you can halve them if using 87 octane.

[camber]

I agree Sutts, that mixture feature of the CloD Spit II does not make sense. I can live with it but I would rather it not be there.

I also am concerned about the fact that top speed in the Hurri and Spits is achieved at lower rpm than maximum (2600-2800 vs 3000). I have not seen any historical reference that to get top level speed, you should retard rpm. On the contrary, maximum speed data is given for 3000rpm.

I suspect it is a consequence of the rpm-boost quirk of the CloD engine model. Lowering rpm from 3000 to 2600 in CloD adds some boost (although in reality the boost controller should be keeping boost constant regardless of rpm). More boost = more power = more thrust in the flight model (presumably), so the non-historical boost increase at lowered rpm gives a corresponding non-historical speed increase at lowered rpm.