Am I doing something wrong with the FW190 D-9?

[SpaydCBR]

I feel like I'm not getting the "advertised speeds" in the D-9. In-game it says it can reach a maximum of 607 kph at sea level. I've found several posts here where people got the same thing. However, it seems I'm only able to get to 561 kph max. Well below that.

 

The way I've been testing this is setting up a quick mission:

• Summer map
• 200l of fuel with no modifications.
• 500m start.
• Autopilot on
• Full throttle
• Boost on

Now I just wait for it to stop accelerating. Always stops at around 560 kph. Without boost I'm seeing a little over 1.5 ata, with boost it goes up to 1.8.

By comparison, same test with the bf 109 K-4 I get a little over 590 kph. In-game says max speed is 599 kph, so close enough.

 

Did something about the D-9 flight model change since its release, or is there something else I'm missing?

[HazMatt]

I've only been playing for a couple months but I have noticed that the D9 here does not seem to have the climb rate or speed that I've seen modeled in other sims. I thought it was just the modeling but there may be something more to it. The K4 on the other hand seems to match the modeling I've seen on other sims with the exception of the 1 minute thing.

[bzc3lk]

2 hours ago, SpaydCBR said:

I feel like I'm not getting the "advertised speeds" in the D-9. In-game it says it can reach a maximum of 607 kph at sea level. I've found several posts here where people got the same thing. However, it seems I'm only able to get to 561 kph max. Well below that.

 

 

 

Winter map I'm getting the 607 kph and the summer map I'm in the region of 595 kph. The winter map performance gain was as expected, with lower outside ambient temperatures.  I don't personally see an issue, see pictures below.

 

 

[CountZero]

4 hours ago, SpaydCBR said:

I feel like I'm not getting the "advertised speeds" in the D-9. In-game it says it can reach a maximum of 607 kph at sea level. I've found several posts here where people got the same thing. However, it seems I'm only able to get to 561 kph max. Well below that.

 

The way I've been testing this is setting up a quick mission:

• Summer map
• 200l of fuel with no modifications.
• 500m start.
• Autopilot on
• Full throttle
• Boost on

Now I just wait for it to stop accelerating. Always stops at around 560 kph. Without boost I'm seeing a little over 1.5 ata, with boost it goes up to 1.8.

By comparison, same test with the bf 109 K-4 I get a little over 590 kph. In-game says max speed is 599 kph, so close enough.

 

Did something about the D-9 flight model change since its release, or is there something else I'm missing?

in game spec give speed on conditions youll have on autum maps, kuban autum is good for testing as you can be over sea at 50m.

and then youll be able to get to 607kmh indicated as spec say.

also you are slow on summer in your test as you didnt set watter thermostat to 0%, you should get 595 then

 

K4 (DB engine) will do 600kmh like spec say, on autum map, on summer is slower then this, on winter is faster

D9 is probably only airplane that dont get big speed benefit when its on winter map compared to autum map, it was explained before why but i dont remenber exactly why now, something to do with the way coling is set up

Edited February 11, 2024 by CountZero

[[CPT]Crunch]

Fw's really benefit well when you apply unloading on them, they'll hold the extra speed gained quite a while.  Read your G meter and push less than one G till the speed peaks, than level and run.  Rinse and repeat.  Don't get caught flatfooted with no altitude.

Edited February 11, 2024 by [CPT]Crunch

[SpaydCBR]

Ahhh, so it was the thermostat. Knew I was just missing something. I always thought everything was automated in the 190s and didn't need to mess with them. Setting it to 0% I was able to hit the 600+kph mark. Thanks CountZero and everyone.

 

Crazy how much of a difference that thermostat makes. Brings me to another question. Is there any reason not to just leave it at 0%? I imagine it's meant to keep the water temps cool, but even on my summer test I didn't notice any danger.

[SpaydCBR]

15 minutes ago, [CPT]Crunch said:

Fw's really benefit well when you apply unloading on them, they'll hold the extra speed gained quite a while.  Read your G meter and push less than one G till the speed peaks, than level and run.  Rinse and repeat.  Don't get caught flatfooted with no altitude.

What does "unloading" mean here? Wouldn't maintaining less than 1 G essentially mean an ever steepening dive (like a negative G split-s)? Or do you mean more like a shallow dive?

[jollyjack]

I very much got used to being lazy in regards of individual plane specific controllers ... custom realism.

[R33GZ]

6 hours ago, SpaydCBR said:

What does "unloading" mean here? Wouldn't maintaining less than 1 G essentially mean an ever steepening dive (like a negative G split-s)? Or do you mean more like a shallow dive?

Kind of... trading altitude for airspeed. The attitude of the dive would be dictated by how quickly you need said airspeed ?

[Hartigan]

22 hours ago, SpaydCBR said:

Crazy how much of a difference that thermostat makes. Brings me to another question. Is there any reason not to just leave it at 0%? I imagine it's meant to keep the water temps cool, but even on my summer test I didn't notice any danger.

In the D-9 model, the cooler is still auto with a 0% You can cool the engine more with the 1-100% setting.

[[CPT]Crunch]

You dump tremendous amounts of drag when you go anywhere between 0 to less than one G, it's a principle of aerodynamics called unloading, cause your rapidly unloading drag.  Faster acceleration times and with less drag your top speeds are higher, getting there you'll hold that speed after you go back to 1 G for some time.  You don't necessarily have to dive, just trade a small amount of altitude.  And yes, it's modeled in GB, most sims have it, if the drag models are even close to being simulated correctly. 

 

Your simply not flying the mustang correctly if you aren't using this.  This is a big reason why correct trim is absolutely vital.

[EAF19_Marsh]

6 hours ago, [CPT]Crunch said:

You dump tremendous amounts of drag when you go anywhere between 0 to less than one G

Just to clarify for the OP, when unloading you remove induced drag, which is that caused by the wing generating lift. If you hold the aircraft at zero g it is roughly at neutral angle of attack so there is no spanwise movement of air caused by the wing. This portion of this drag is 30%-plus of total drag, so by doing this you just made your ride that much slippier.

 

Note this does not effect form drag (the air simply hitting your aircraft) or skin drag (which is more complicated but IIRC is the effect your aircraft has on the air in every way except through generation of lift - which is the induced drag mentioned above). Some knowledgeable chap can likely add a lot more / better stuff.

I suspect in WW2 is was more learned than taught but today it is a basic part of aircraft handling, albeit not used much in GA.

 

Mess about and see the results.

 

[Lusekofte]

Yes

[CUJO_1970]

D-9 Mass Flow regulator is set for standard atmosphere. The sim interprets this and executes the result as the D-9 suddenly loses ~50 mph in top speed to certain other aircraft in the sim because it's little colder outside.

 

This I would say is a sim limitation that while perhaps technically correct, implements it in an ahistoric manner. If this was really the case historically we would know about it.

[BlitzPig_EL]

That is very strange, as normally engines make more power in colder, denser air.

[ZachariasX]

39 minutes ago, BlitzPig_EL said:

That is very strange, as normally engines make more power in colder, denser air.

That is because in „normal“ engines, you get more air (mass) per time interval into the engine, giving more power in excess of the nominal power. This excess in power cancels out the added drag of the colder and thus denser air.

 

With a mass flow regulator, the engine produces the same amount of power in cold as in hot(ter) air, meaning the added drag in cold weather is not offset and you get a reduction in airspeed.

 

Conversely, in hot air, MAP regulated engines (like the Merlin) lose power below nominal output and thus airspeed, while the mass flow regulated engine „overcharges“ (if it still can and is not maxed out already at altitude) the air input to the degree of offsetting the lower ambient air mass and maintaining nominal air mass flow.

 

The game reproduces that in a rather exact manner as I have found out upon checking it.