Inaccurate performance data for BOB fighters in COD comparing to RL data

[bongodriver]

Originally Posted by Crumpp

Where does it clearly say that?

It does not, the General Operating Notes clearly say he can use it.

Yes but only with 100 octane.

p.s. who did you quote?

[NZtyphoon]

Originally Posted by Crumpp

Where does it clearly say that?

It does not, the General Operating Notes clearly say he can use it.

Read the Merlin Operating notes again; "It is emphasised that high boost for emergency may only be employed with 100 Octane fuel..."

The Pilot's Notes General were to be be used in conjunction with the aircraft's Pilot's Notes, and with any limitations pasted into those notes using supplementary slips, and with the Merlin Engine operating notes: the Pilot's Notes General were never specific to any particular aircraft type.

[Seadog]

Originally Posted by Crumpp

No Seadog, it was possible as we can see from the Operating Notes. I am sure that engine was trashed after overboosting to +16lbs but it was definately possible on 87 Octane fuel.

It definately was not good but it was possible. Pulling the tit and overboosting the engine is not proof of the use of 100 Octane fuel.

Pulling the boost override with 87 octane would be equivalent to committing suicide; even if the engine didn't fail immediately, it would lose power due to premature detonation. Why in God's name would any sane pilot "pull the plug" if it resulted in loss of performance?

Yet, in all the combat reports of the pilots pulling the plug, the aircraft responded with increased performance; there are no reports where the engine began to suffer detonation and/or failed...

[Kurfürst]

... will it make 2000?

[Ernst]

Originally Posted by klem

Well a key point about the spitfireperformance website is it gives us data collected at the time in reports written at the time. It is unlikely that Russian test organisations would have got any nearer to the true performance figures than the companies building the aircraft and engines and their prime user the RAF and its test organisations.

Yes, but the companies wants to sell the aircrafts. That tests were made with unique prepared aircrafts for sure. A front line fighter would perform different. Some aircraft were easier to maintain and repair and were most of time more "combat ready" and "trimmed" than others, or even the perfomance downgrade by wearing should be much less. Even the way the aircraft is painted or waxed made a big difference in performance. Do you think 30km/h or 60 km/h should be a great difference? An 110 nightfighter with 52 victories, named Martin Drewes, stated that it was possible to fly 30km/h faster if they do not wax their aircraft or even removing the camouflage. He says: Better to fly faster than have a better looking aircraft.

Conclusion: There are many variables in the performance showed in this tests. For sure that aircraft were prepared or used advantageous methods of analysis to match the performance requiriments in the contracts. Problaby if an aircraft had more difficult mainentance in front line it ll be most of time deviated from that "original" performance.

[klem]

Originally Posted by Ernst

Yes, but the companies wants to sell the aircrafts. That tests were made with unique prepared aircrafts for sure. A front line fighter would perform different. Some aircraft were easier to maintain and repair and were most of time more "combat ready" and "trimmed" than others, or even the perfomance downgrade by wearing should be much less. Even the way the aircraft is painted or waxed made a big difference in performance. Do you think 30km/h or 60 km/h should be a great difference? An 110 nightfighter with 52 victories, named Martin Drewes, stated that it was possible to fly 30km/h faster if they do not wax their aircraft or even removing the camouflage. He says: Better to fly faster than have a better looking aircraft.

Conclusion: There are many variables in the performance showed in this tests. For sure that aircraft were prepared or used advantageous methods of analysis to match the performance requiriments in the contracts. Problaby if an aircraft had more difficult mainentance in front line it ll be most of time deviated from that "original" performance.

Most of the tests were undertaken by the RAE, the bona fide testing organisation for the British Airforce testing on behalf of the government, these were not "manufacturer's tests". Manufacturer's test results were not the way aircraft gained approval. The RAF would not have accepted aircraft designs without the RAE's input and it was not in the RAF/Air Ministry's interest to generate false results when they were trying to determine the capabilities of their fighters to defend the country. These were production standard aircraft. Yes they may have been fairly new but where would you like them to have started? With clapped out front line aircraft?

As for wax/no wax/wear/trimmed etc., how would you like 1C to set up the Spitfires and Hurricanes, oh, and of course, the 109s? Worn/degraded to 90% performance? Or do you want 100% condition 109s and 85% condition RAF aircraft?

1C can only begin by assuming production standard aircraft, take data from genuine contemporary tests and use that. If they want to model in wear thats fine. For Axis aircraft too of course.

Some of these arguments are becoming ridiculous.

[KG26_Alpha]

Originally Posted by Seadog

Pulling the boost override with 87 octane would be equivalent to committing suicide; even if the engine didn't fail immediately, it would lose power due to premature detonation. Why in God's name would any sane pilot "pull the plug" if it resulted in loss of performance?

Yet, in all the combat reports of the pilots pulling the plug, the aircraft responded with increased performance; there are no reports where the engine began to suffer detonation and/or failed...

Probably because they never had the good fortune to make a combat report.



The ridiculous arguments are valid of course, as everyone has thier opinion of how it should be in CoD.

None of it matters because as soon as the RAF get 100 octane there will be a new axe to grind here.

Most likely ammunition effectiveness with a forum full of graphs and charts showing pretty much what we have now,
peoples opinions on how CoD should be.


Carry On







.

[Skoshi Tiger]

Originally Posted by Seadog

No, the engine couldn't run at 10.5lb boost with 87 octane fuel.

I was just going by those test certificate posted previously. Noting in the documents stated that their power curve had been extrapolated, So I can only assume that the figures were obtained by testing.

Originally Posted by Seadog

The story about the pilot modding his engine with a match stick pertained to a Merlin III using 100 octane fuel and an unauthorised mod to obtain 16lb boost at low altitude

I stand corrected.

Cheers!

[Skoshi Tiger]

Originally Posted by Seadog

Yet, in all the combat reports of the pilots pulling the plug, the aircraft responded with increased performance; there are no reports where the engine began to suffer detonation and/or failed...

Could that be that when the pilots 'pulled the plug' the boost was still at a level before detonation occurs.

One of the pilot stories (show in this thread) before did mention black smoke comming from the exhaust and the plane vibrating a lot. Sound like he was pushing it a bit too far. But none of the others mentioned it.

[TomcatViP]

Well, I can found dozens of 70+ smokers that did not get any Cancers and makes them testify about how safe was the cigarettes for them.

Would you then believe that Smoking is good for your health ?