Spitfire makes only 300 mph?

[reflected]

I dare anyone to fly the Spit MK2 faster than that. It's supposed to make 350mph, but no matter how I adjust my prop, it jsut wouldn't go faster. The max speed I can reach in the MKI is about 250. What am I doing wrong? Full real except for temp.effects. :(

[Kurfürst]

Indicated airspeed show by your speed gauge is generelly less than True Air Speed. There is a conversion table in the manual.

[reflected]

I know, it was at sea level :(

[lacusch69]

Srácok, ezt magyarul is megbeszélhettétek volna... ;)

(Both guy is hungarian)

[Blue Scorpion]

Several people including myself have already posted on the performance level of spits and hurri's they appear to be seriously porked, and nowhere near where they should be for 100-octane fuel. Boost levels are wrong, as is rate of turn, roll, and climb, frankly the fm performance data is less sim and more arcade atm, that, or the in game instruments and behaviour are wrong.

I gave up trying to evaluate anything else, as frankly far too much is broken, or not working as intended to make reasonable assessments, until the basics are fixed, it's back on the shelf.

[JG53Frankyboy]

..............I gave up trying to evaluate anything else, as frankly far too much is broken, or not working as intended to make reasonable assessments, until the basics are fixed, it's back on the shelf.

very good summary !!
i also gave up...

[ICDP]

I took a Spitfire MkII on a seal level speed test, quick mission over the channel. With a well trimmed and slightly open radiator I was able to get about 311mph IAS. This speed would indicate the Spitfire MkII is indeed using 100 octane fuel.

Make sure to adjust your prop for best speed, this isn't IL2 where you leave it on 3000 RPM at all times. I found the best to be around 2600 - 2800 RPM.

Inidentally, the boost guage only goes up to 8lb but that doesn't mean that is the bost we get. Spitfires in BoB still had the old boost guage and when pulling full boost the needle was off the guage with 100 octane fuel.

As I said, the speed seems to match a MkIIa with 100 octane fuel.

[fruitbat]

I took a Spitfire MkII on a seal level speed test, quick mission over the channel. With a well trimmed and slightly open radiator I was able to get about 311mph IAS. This speed would indicate the Spitfire MkII is indeed using 100 octane fuel.

Make sure to adjust your prop for best speed, this isn't IL2 where you leave it on 3000 RPM at all times. I found the best to be around 2600 - 2800 RPM.

Inidentally, the boost guage only goes up to 8lb but that doesn't mean that is the bost we get. Spitfires in BoB still had the old boost guage and when pulling full boost the needle was off the guage with 100 octane fuel.

As I said, the speed seems to match a MkIIa with 100 octane fuel.

i think you may be right, figures i have (P 7280 test Boscombe Down sept 1940) show spit MkII top speed at 290mph at sea level on 9lbs boost.

@25 mph is about right for the diff between 87 octane and 100 octane fuel at sea level according to my sources, so pretty close.

Spit MkII according to this test, makes 354mph at 17554ft.

[Kurfürst]

Make sure to adjust your prop for best speed, this isn't IL2 where you leave it on 3000 RPM at all times. I found the best to be around 2600 - 2800 RPM.

Inidentally, the boost guage only goes up to 8lb but that doesn't mean that is the bost we get. Spitfires in BoB still had the old boost guage and when pulling full boost the needle was off the guage with 100 octane fuel.

As I said, the speed seems to match a MkIIa with 100 octane fuel.

Looks like it's only a faulty boost gauge Than.. :)

Anyway it seemed to me that Oleg modelled the MkII as CSP+100 octane, the Mk Is are with two pitch props and 87 octane. Good choice IMHO.

The thing about rpm is odd though. I believe you have to fly 3000/+12 to get max speed, less rpm should yield less power.. CSPs seem buggy too, far from being "complex", as in RL, where u had to operate throttle and rpm in set sequence to avoid over/underboosting, right now they work like German automated throttles, where u operate a single lever and görget about the rest..

[reflected]

Not to mention that the Spit MK Ia should have a CS prop as well...

[41Sqn_Stormcrow]

I fly the Spit 2a frequently and did some tests. With max boost without cut out and max rpm I get about 290- mph (about 6kft) and almost 300 mph with all out. Radiators fully open as to avoid water overheating.

10 mph win for all out? That's quite little I'd say ...

[ICDP]

I just checked again and the MkII does only show 8lbs boost according to the no cockpit guages. It does however get 311-315 MPH at sea level, so it is getting 100 octane 12+Lbs boost SL speeds.

The MkI is woefully underperforming right now, 260MPH at sea level.

The Me109 is also getting way less speed than it could in reality at SL. I can get 450kph, this is 40-50kph too slow.

It seems that the poor performance is not just limited to the graphics engine. In all honesty the fact that people are getting stutters and poor FPS has deflected away from the fact that there is a lot more wrong with CoD. People are only just starting to notice the other serious issues.

It is a good sim, it just needs a lot of work... to be continued.

[ICDP]

I fly the Spit 2a frequently and did some tests. With max boost without cut out and max rpm I get about 290- mph (about 6kft) and almost 300 mph with all out. Radiators fully open as to avoid water overheating.

10 mph win for all out? That's quite little I'd say ...

Make sure to go to no cockpit view for a much more accurate reading. The little info bar on the IAS inside the cockpit only reads in increments of 10. So 315 will still read 310 for example.

[fruitbat]

the Mk Is are with two pitch props and 87 octane. Good choice IMHO.



lol, would have to seriously disagree with this, one of them yes but both is stupid imo, since the mkI was the mainstay of the battle and theres so much evidence of lots (note not all) of them on 100 octane fuel, which even you have to admit.

[Kurfürst]

lol, would have to seriously disagree with this, one of them yes but both is stupid imo, since the mkI was the mainstay of the battle and theres so much evidence of lots (note not all) of them on 100 octane fuel, which even you have to admit.

You are right (posting from an iPhone was pain.. ). There should be be a 2-pitch version, and a CSP with armor, both 87 octane. The Mk. II could then be used as a stand in for Mk. Is with 100 octane as well. Of course a third Mark I with 100 octane and CSP would be great as well, but IMHO redundant as its the same thing really as the current Mk. II performance wise.

I was just testing one Mk I (dunno Mk I or Mk Ia so I am not sure, but evidently at least one of them is with 2 pitch screws), as I was curious about how the CSP works in COD.

Il-2 was a serious disappointban the way it modelled CSP. Still is.. you don't seem to select RPM with it, as you should, you select "relative to maximum allowed rpm for given boost".

Speaking of which, "Mk Ia" is also a bit weird. AFAIK there was no such actual designation, it was Mk I. Mk IA is an ex post facto "designation", maybe born in post-war literature, like "Erla G-10". Hell some books even state the "Mk. I" was with four guns only..

[b101uk]

The thing about rpm is odd though. I believe you have to fly 3000/+12 to get max speed, less rpm should yield less power..

max RPM would have more power but less torque, a slightly lower RPM e.g. 2600 to 2800 rpm would have less power but more torque.

Engines are at there happiest when ran ~2/3rd & 4/5th of the way between peak torque RPM and rated power RPM, so for the sake of maths lets say rated power is 3000rpm and peak torque is 2000 rpm then 2/3rd would be 2666rpm and 4/5th would be 2800rpm, as this is ware you get a good balance of actual torque and notional power.

You did now that power is a notional figure derived from force vs. speed so e.g. 1HP = 550lbft/sec or 33000lbft/min or anything that amount to the same, so both 1lb @ 550ft/sec & 550lb @ 1ft/sec are equal to 1HP. ;)

[fruitbat]

disagree with the mkII and mkI being the same performance.

mkI is marginally faster down low, mkII quicker up high, and more importantly, a higher service ceiling, which put them 3000ft above the 109's, at least according to one German fighter pilots book i've read (Spitfire on my tail). In October he described it 'as regular as the German railway' for spits to be waiting for them well above there service ceiling.

figures i have list service ceiling for mkII as 37,600ft (P7280), vs 34,700ft for mkI (N3171), figures i have for E3 34,550ft.

Thats why it makes much more sense to me to have one spit MkI at 9lbs, one at 12lbs and the spit MkII at 12lbs, along with an E1 and E4 of course. Then we can actually start having a Battle of Britain.

agree re the mkIa thing, its just plain weird!

[Redroach]

I dare anyone to fly the Spit MK2 faster than that. It's supposed to make 350mph, but no matter how I adjust my prop, it jsut wouldn't go faster. The max speed I can reach in the MKI is about 250. What am I doing wrong? Full real except for temp.effects. :(
I know, it was at sea level

Heh, sorry, but I had to smile about that for a long time ;)
Being a test pilot is not just "fly around somehow" and then bash the developers. You also have to get your physics right. You have to be the absolute master over your machine (and I seriously doubt anyone has already mastered CEM to the full extent) - and you have to be able to set reproduce-able conditions.

Well, the third point is not even conceivable right now from what I read here, but the first two... Guys, I'd respectfully suggest doing a lot more "flight schooling" before you jump to conclusions like "Plane XX is woefully undermodelled" or "They've got to get their flight models right". No, it's the other way round - people got to get their test flights right, judging from what has been written here.
I hope the devs don't jump to overly nervous conclusions... but, seeing they are all battle-hardened veterans with own flight experience, I shouldn't be too scared, I hope :)

P.S.: Oh, and as always on the internet: Screenshot or it didn't happen! ^-^

[reflected]

Heh, sorry, but I hat do smile about that for a long time ;)
Being a test pilot is not just "fly around somehow" and then bash the developers. You also have to get your physics right. You have to be the absolute master over your machine (and I seriously doubt anyone has already mastered CEM to the full extent) - and you have to be able to set reproduce-able conditions.

Well, the third point is not even conceivable right now from what I read here, but the first two... Guys, I'd respectfully suggest doing a lot more "flight schooling" before you jump to conclusions like "Plane XX is woefully undermodelled" or "They've got to get their flight models right". No, it's the other way round - people got to get their test flights right, judging from what has been written here.
I hope the devs don't jump to overly nervous conclusions... but, seeing they are all battle-hardened veterans with own flight experience, I shouldn't be too scared, I hope :)

OK master test pilot, go ahead and fly it at 350 mph level! ;)

[Kwiatek]

The most common Spitfire MK1-MK2 version should be:

Spit MK1 Merlin III ( pre BOB version) - 2 stage DH prop pitch, +6 1/2 lbs (87 octan fuel), no armoured windshield and no pilos armour ( the fastest SPit Mk1 at FTH but worse climb rate )

Spit MK1 Merlin III ( BOB version -could be MK1A) - CSP DH , +12 lbs ( 100 Octan), armoured windshield ( the fastest Spit MK1 at low level, good climb rate)

Spit MK2 Merlin XII - CSP Rotol, +12 lbs ( 100 Octan), armoured windshield and pilot armour)



Similar should be with Hurricanes:

Hurricane MK1 ( early) - 2 stage DH prop, +6 1/2 lbs ( 87 octan fuel)

Hurricane MK1 ( late) - CSP DH2, +12 lbs ( 100 Octan), armoured windshield ( pilot armour)

[41Sqn_Stormcrow]

The spit 2a should have a Merlin XII which ran at 9 lbs/ sq.in without boost cut-out. I believe that no plane would be fitted with a boost indicator that even doesn't show the nominal max boost. Currently the clock only shows 8 with boost cut-out. Also you have to have boost cut-out to exceed 6.2 lbs /sq.in

I think this is a bit strange. I think our Spit 2a is no Spit 2a but a Spit 1a with small modifications.

[fruitbat]

The most common Spitfire MK1-MK2 version should be:

Spit MK1 Merlin III ( pre BOB version) - 2 stage DH prop pitch, +6 1/2 lbs (87 octan fuel), no armoured windshield and no pilos armour ( the fastest SPit Mk1 at FTH but worse climb rate )

Spit MK1 Merlin III ( BOB version -could be MK1A) - CSP DH , +12 lbs ( 100 Octan), armoured windshield ( the fastest Spit MK1 at low level, good climb rate)

Spit MK2 Merlin XII - CSP Rotol, +12 lbs ( 100 Octan), armoured windshield and pilot armour)



Similar should be with Hurricanes:

Hurricane MK1 ( early) - 2 stage DH prop, +6 1/2 lbs ( 87 octan fuel)

Hurricane MK1 ( late) - CSP DH2, +12 lbs ( 100 Octan), armoured windshield ( pilot armour)

sounds perfect.

[reflected]

sounds perfect.

+1

[lane]

The most common Spitfire MK1-MK2 version should be:

Spit MK1 Merlin III ( pre BOB version) - 2 stage DH prop pitch, +6 1/2 lbs (87 octan fuel), no armoured windshield and no pilos armour ( the fastest SPit Mk1 at FTH but worse climb rate )

Spit MK1 Merlin III ( BOB version -could be MK1A) - CSP DH , +12 lbs ( 100 Octan), armoured windshield ( the fastest Spit MK1 at low level, good climb rate)

Spit MK2 Merlin XII - CSP Rotol, +12 lbs ( 100 Octan), armoured windshield and pilot armour)

Similar should be with Hurricanes:

Hurricane MK1 ( early) - 2 stage DH prop, +6 1/2 lbs ( 87 octan fuel)

Hurricane MK1 ( late) - CSP DH2, +12 lbs ( 100 Octan), armoured windshield ( pilot armour)

+1
(Although I don't really see much point in the 87 octane set up except maybe for Hurricanes in France during the phoney war period).

[*Buzzsaw*]

Looks like it's only a faulty boost gauge Than.. :)

Anyway it seemed to me that Oleg modelled the MkII as CSP+100 octane, the Mk Is are with two pitch props and 87 octane. Good choice IMHO.

Good choice for those who want the British to have aircraft with 1938 performance.

The facts are out there, despite the disinformation you post, and it is clear 100 octane was in predominant use, with 100% of the sector airfields in No. 10, 11 and 12 Group, showing clear use of 100 octane during the battle.

It is also very clear the two pitch De Havilland props in the Spitfire I were upgraded to constant speed in early July. In addition, all new Spitfires, (which were 50% of the aircraft on strength by September) coming off the production lines had constant speed props.

The facts have been shown on posts on this board, you have provided ZERO proof to the contrary.

By the way, the Spit 1A in the game is modelled graphically with a CSP Rotol prop, as historically it was, who knows why Luthier suddenly reversed the Flight Model. Who knows what false information was directed his way.

[*Buzzsaw*]

The spit 2a should have a Merlin XII which ran at 9 lbs/ sq.in without boost cut-out. I believe that no plane would be fitted with a boost indicator that even doesn't show the nominal max boost. Currently the clock only shows 8 with boost cut-out. Also you have to have boost cut-out to exceed 6.2 lbs /sq.in

I think this is a bit strange. I think our Spit 2a is no Spit 2a but a Spit 1a with small modifications.

The graphics model is of a Spit II. It has the six exhaust stubs per side instead of three, and there are other elements.

However, it doesn't even have the performance of a historical BoB Spit Ia at +12.

[ICDP]

The graphics model is of a Spit II. It has the six exhaust stubs per side instead of three, and there are other elements.

However, it doesn't even have the performance of a historical BoB Spit Ia at +12.

The Spitfire II did not have six exhaust stubs per side, it had three. Have you tested the MkII in CoD yet? At SL it is getting correct speeds even with only 9lbs boost, I haven't tested all other altitudes yet but so far it looks like only the boost is being reported wrong.

So far the indications are that the MkIs are not modelled correctly and the CSP is broken on the MkIa, they both underperform quite badly.

The 109E is also performing well below its actual real performance.

It seems there is a lot of work required on getting the FMs and performance fixed on most aircraft.

[reflected]

I tried to fly the Spit MKI with full CEM. If you give enough throttle to climb a little the oil temperature goeas above 90 and your engine dies. Incredible...:confused:

And no, I'm not a sim noob, I know what's what in an aeroplane.

[lane]

Good choice for those who want the British to have aircraft with 1938 performance.

The facts are out there, despite the disinformation you post, and it is clear 100 octane was in predominant use, with 100% of the sector airfields in No. 10, 11 and 12 Group, showing clear use of 100 octane during the battle.

It is also very clear the two pitch De Havilland props in the Spitfire I were upgraded to constant speed in early July. In addition, all new Spitfires, (which were 50% of the aircraft on strength by September) coming off the production lines had constant speed props.

The facts have been shown on posts on this board, you have provided ZERO proof to the contrary.

By the way, the Spit 1A in the game is modelled graphically with a CSP Rotol prop, as historically it was, who knows why Luthier suddenly reversed the Flight Model. Who knows what false information was directed his way.
-----
The graphics model is of a Spit II. It has the six exhaust stubs per side instead of three, and there are other elements.


Good posts. Two minor quibbles though; I've seen late June into early July for DH conversions (earlier for Rotol) and what photos I have of Spitfire IIs shows 3 exhaust stubs per side. Nice photo attached of a No. 19 Squadron Spitfire II at Fowlmere during September 1940.

[winny]

You are right (posting from an iPhone was pain.. ). There should be be a 2-pitch version, and a CSP with armor, both 87 octane. The Mk. II could then be used as a stand in for Mk. Is with 100 octane as well. Of course a third Mark I with 100 octane and CSP would be great as well, but IMHO redundant as its the same thing really as the current Mk. II performance wise.

I was just testing one Mk I (dunno Mk I or Mk Ia so I am not sure, but evidently at least one of them is with 2 pitch screws), as I was curious about how the CSP works in COD.

Il-2 was a serious disappointban the way it modelled CSP. Still is.. you don't seem to select RPM with it, as you should, you select "relative to maximum allowed rpm for given boost".

Speaking of which, "Mk Ia" is also a bit weird. AFAIK there was no such actual designation, it was Mk I. Mk IA is an ex post facto "designation", maybe born in post-war literature, like "Erla G-10". Hell some books even state the "Mk. I" was with four guns only..

All 8 gun RAF fighters were retrospectivley given the A suffix sometime in late 1940. Up till then they were just Mk 1s.

I'm wondering if the 'Early' Mk1 is just exactly that, early (Pre June '40). More of a Battle of France Spitfire, 2 speed De Hav and 87 octane. That would make more sense.

Here's an interesting pont. The first Modified (ie the cannons worked) Mk IB into action in the BoB was R6889, 19 Sqn . It was, to quote Spitfire, The History "Not an outstanding sucess, it was underpowered, even with the Merlin III and had to be flown at maximum power just to keep up with the browning armed Spitfires"

[Deadstick]

Hahaha, more Spitfans complaining because it is not über like in IL 2. :-P

Actually, even though I mainly fly Blue, I agree. I found this in a nother thread :

Of course, the Spit I's in the game, both the standard and Ia are completely porked. Both have the dual speed props, which is not accurate. 100% of the Spit I's with De Havilland dual speed props were converted to De Havilland constant speed props, most by the end of the first week of July, the rest by the end of August. Plus all new models coming out of the factory had Rotol constant speed props factory installed.


I'm not saying it proves they are not modelled correctly, but if they have not even got the props right, what else is wrong?

[ICDP]

Well after some more testing of the Mk IIa I must say it is modelled perfectly on a real +12 lbs boost Spitfire Mk IIa for top speeds.

These numbers are taken at full CEM and engine overheat enabled. *Warning* Disabling CEM or overheat results in a Spitfire Mk IIa capable of 390MPH. Do not use CEM or overheat OFF for speed testing.

http://i17.photobucket.com/albums/b58/ICDP/CoDSpitfireMkIIaSpeeds.jpg

As can be seen the Mk IIa speeds are spot on when compared to a +12 lbs boost Spitfire Mk Ia. The speeds are around 20-25mph faster than the 9 Lbs boost Mk II a speeds which would put them about right for 12 lbs boost. Also at the full throttle height of around 18,000 ft the boost there should be no speed difference between 9 lbs or 12 lbs boost.

The Mk IIa in CoD (at least in speed for altitude) is definately a 12 lbs boost version. The guage in CoD is broken. I will add climb tests later.

[Peril]

Looks like it's only a faulty boost gauge Than.. :)



The thing about rpm is odd though. I believe you have to fly 3000/+12 to get max speed, less rpm should yield less power..

Not less power 'to the air' if your prop is entering compression FX due to high tip speeds. Power to the engine is one thing, transferring this to the prop/air another. The larger props in Targetware also had the same effect where props became inefficient in this manner at high RPMs..

Perhaps the props data/size is wrong if this is incorrect here?

Food for thought.

[41Sqn_Stormcrow]

Can you tell me how I get the 317 at SL in COD with CEM? My procedure is:
All out (max rpm, max boost with boost cut out) then trim aircraft. Optimize rpm (slightly lower seems to improve speed), let it settle, retrim aircraft, then close radiator just as much to stay at water temperature still acceptable (120°C). Retrim if necessary.

I only get 300 mph at sea level. And this with several trials.

[ICDP]

41Sqn_Stormcrow,

Make sure you use the no cockpit view. The internal speed guage jumps aroung quite a bit and the little info box only shows increments of 10.

So if you use the info box (move your mouse over the instruments) your speed might be showing a 300 but in reality it could be 309. My top speed has ranged from 311 to 317, there doesn't seem to be any reason for the difference apart from my varing flying skills :)

I open the radiator 5 or 6 clicks from fully closed for optimum cooling and speed. I am not sure if it is modelled in CoD but the real Spitfires would give slightly better speeds with the radiators slightly open. This position was known as the minimum drag position and was marked by a red or white triangle on the map box beside the radiator lever. Open the radiator further than the triangle and the increased drag would slow the aircraft down. Close the radiator further back from the read triangle and the decreased cooling would cause the engine to overheat, thus requiring a reduction in power.

Unfortunately the CoD Spitfire has the radiator lever slightly forward from the correct position so it wouldn't line up with this red triangle even if it did exist on the CoD Spitfire.

[Viper2000]

Not less power 'to the air' if your prop is entering compression FX due to high tip speeds. Power to the engine is one thing, transferring this to the prop/air another. The larger props in Targetware also had the same effect where props became inefficient in this manner at high RPMs..

Perhaps the props data/size is wrong if this is incorrect here?

Food for thought.

Typical tip Mach numbers were around 0.9ish (column #6); typical prop efficiencies were around 70-80% (column #12/13), and shock losses were assumed to be about 7% (column #14).

http://www.spitfireperformance.com/spit2prop-b.jpg

[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.

[Viper2000]

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:

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 ;) .
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.
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...
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! :-P

[IvanK]

Point 1 yes agree but thats as I flew the test on the day.
Point 2 Yes aware of that, there is a pretty reasonable chart of this in the AP2095
Point 3 No PEC as I don't think (but will confirm) its modelled in the game (No in game data)
Point 4 Not yet

[Viper2000]

Point 1 yes agree but thats as I flew the test on the day.
Point 2 Yes aware of that, there is a pretty reasonable chart of this in the AP2095
Point 3 No PEC as I don't think (but will confirm) its modelled in the game (No in game data)
Point 4 Not yet

Various observations in no particular order:

I've been trying to replicate your test with overheat enabled, and the results are somewhat "interesting".

Even if I climb somewhat fast and open the radiator all the way, there's quite a high probability of something breaking by the time the aeroplane gets to 15000' indicated.

I am using the free flight over the channel QM.

It isn't a standard day; setting 1013 millibars on the altimeter and then flying suicidally low & slow results in an indicated altitude of 500 feet.

The standard guess of 30'/mb gives QNH of 996 mb, which checks out in the sim. I don't know how to work out OAT or humidity to perform a density altitude calculation, and at this stage I also don't know whether the ambient pressure is global or local. I was planning to test this by flying low over the sea in the south-west and north-east corners of the map, but that's a long way to fly in a Spitfire, especially given the problems with setting cruise power correctly.

Come to think of it, I should probably copy some of this stuff over to my flight testing thread at some point...

Interestingly, the "no cockpit" altimeter displays true altitude above the sea "out of the box".

Likewise, the "no cockpit compass" displays true heading, whilst the compass in the aeroplane appears to suffer from quite a lot of magnetic variation (almost 20 degrees West; I was expecting more like 10 for 1940, though it's really hard to read the compass in 720p resolution...). [There is no compass card in the cockpit, so I assume that the difference between indicated and must be entirely due to magnetic variation.]

Looking at the engine exhaust, it seems that we only get a sensible mixture at sea level, and the sim doesn't understand auto rich & auto lean.

Negative g rich cut also seems to get worse at higher altitudes, which would support this hypothesis.

I also note with interest that leaning the mixture affects the boost pressure, which I don't understand...

[IvanK]

I was running 997mb.
Pretty sure Magvar is not modelled. 10W is what it was in 1943

There is an OAT gauge in the HEIII up over your right shoulder. A similar one in the JU88 on the right side wall.

[Xiola]

I dare anyone to fly the Spit MK2 faster than that. It's supposed to make 350mph, but no matter how I adjust my prop, it jsut wouldn't go faster. The max speed I can reach in the MKI is about 250. What am I doing wrong? Full real except for temp.effects. :(

It only goes 350mph at its fastest height.

If you are at sea level, I believe the top speed is 292mph

[Redroach]

Finally! The first one to realize that! *cheer*

[ICDP]

It only goes 350mph at its fastest height.

If you are at sea level, I believe the top speed is 292mph

292 at SL is Correct for a Mk IIa running +9 lbs
For a +12 lbs boost it should (and does) get around 310-315mph


Finally! The first one to realize that! *cheer*

Well spotted... I pointed out that the Spitfire Mk IIa was a +12lbs boost version on the first page of this thread. :)

[b101uk]

Likewise, the "no cockpit compass" displays true heading, whilst the compass in the aeroplane appears to suffer from quite a lot of magnetic variation (almost 20 degrees West; I was expecting more like 10 for 1940, though it's really hard to read the compass in 720p resolution...). [There is no compass card in the cockpit, so I assume that the difference between indicated and must be entirely due to magnetic variation.]


perhaps the 20 degrees West is some confusion between magnetic North vs. NAD27/OSGB36/WGS84/ETRS89 ellipsoid OSGB/UTM and other 2d geographic projections based on a cylinder

i.e. the map system and the location of magnetic North is plotted in 3d space using a 2d geographic projection (the distance between 1deg latitude at the equator is show the same as 1deg latitude near the poles) however the game world uses an ellipsoid so the more north/south you are from the equator the shorter the distance between each 1deg of latitude.

The above would cause magnetic north to appear hundreds of KM further west than it was, this could also account for some speed errors as to get a “speed” you must be travailing relative to something and the problem could come if it’s a distorted geographic projection vs. a true representative ellipsoid dependent on if your in the south or north of the map travailing east><west.