Looks very bad for low altitude even only for 6 1/2 lbs performacne :(

Not mention of absense 100 Octan fuel performacne :(

So thats why we didn't get full altitude speed polars of British fighters on graph?

Comone 1C i belive you could do it much closier to RL data the same you could make +12 lbs boost implement for British fighters!

Idea with blocked/unblocked Boost Cut-Out depend of using type of fuel octan is really not bad. Try it before patch relase plz !!!

This IS about being accurate. You can't say you want it accurate and then on the other hand imply that klem is being pedantic. 28mph is a lot of speed.

I did not, maybe you need read my post again.


Edit:

I did a edit for better compression.

This trial: http://www.kurfurst.org/Performance_...w_109V15a.html

certainly suggest that it is so. They were running the plane at 1,31-1,33ata, and radiators were only 1/4 open (streamline position), yet coolant temperature could be maintained at constant 90 degrees Celsius, an optimum for the engine., so in practice it means that the aircraft should not overheat with the coolant in level flight and max power. (though it may reach somewhat higher temps in climbs).

The oil cooler was also closed (in practice its slightly open as it physically cannot close completely IIRC), yet oil temp remained at 62/82 Celsius. Its maintainable indefinietely for the 601A.

Of course the outside temperature during the test was somewhat low, at 5 Celius, so at higher temps we get somewhat higher temps, but not by much, and probably well within limit. The DB 601A could maintain a bit over 100 degrees Celsius coolant temperature indefinietely.

I have not seen one yet. But the performance is easily estimated with reasonable accuracy, as power requirements increase with the cube (ie. for 10% higher speed you need 33% more power). We know what the 109E did on the 5-min 1.35ata (497 km/h) and how much power 1.35 ata meant (1045 PS).

From that the 1-min 1.45ata (which gave 1175 PS, +12.44% power) is easy to calculate, that at +12.44% power the plane will be around 3.98% faster.

That's around 517 km/h at SL, on the 1-min WEP.

Yes, the 109E even with the patch will be still a little bit slow, but I think its much better than previously, when it was 40 km/h slower than it should be... I hope the devs will eventually find some time to polish it further. OTOH the serial produced planes had a certain tolerance.

The 109E type specification sheet (http://kurfurst.org/Performance_test...chreibung.html) where is taken from does not say the power rating. However given the the results of the first test posted, which gave 497 km/h at 1.35ata, and this list 500 km/h, its 95% certain that this page is for the 5-min rating (1.35ata), and not including the boosted 1-min rating. Unless one wants to believe that +135 PS gave a speed boost of 3 km/h...

In short to make 'perfect' 109E model, it should make ~500 on the deck with 1.35, and ~515 with the 1-min WEP.

Coolant temperature should stay around 90 (indefinitely maintainable, ie. no overheat) at high speed flight with the radiator flaps 1/4 open, and oil temperature should stay around 60-80 Celsius with the oil cooler fully closed.

In addition, the radiator drag should be correctly modelled (I believe it does not given much if any drag on all planes in the current model). In reality fully opening it slowed down the plane by about 50 km/h - of course given the above, its a rather theoretical consideration, given that could perfectly maintain the aircraft cool in flight. The same was not the case on the ground however!

I absolutely agree, we need a +12 lbs version of the Spit I next to the existing 87 octane version. The Spit II I am afraid is correct, the type was limited to +9 lbs during the BoB, even with 100 octane, which meant 460-470ish top speed at SL, and was considerably slower than the +12 Spit I version or the 109E.

What is so 'unhistorical' about it?

28mph is a lot of speed, yes, but that´s with Boost.

The performance line posted by B6 is the base performance line, meaning without Boost.

If you make a base performance line with the performance of Boost line then you will have a aircraft with the Boost on all the time, and that´s obviously unrealistic.

You should make the base line performance and then model a Boost behavior that provides the performance of Boost performance line.

And that mean model a high altitude, overheating and damage behavior for Boost too, that´s not easy but they are on it.

I´m full for historic accuracy and for the correct Boost implementation, of course.

I love how Kurfurst posts data with 'calculated' and 'estimate' figures but no actual flight tests. This would be fair enough but for the fact that it's the opposite stance he takes when dealing with RAF data.

Just thought I'd throw that out there before people start to actually believe this guy, just in case you aren't aware of his reputation.


At present the 12lbs boost is simply not modeled, so even applying it is not possible. Nobody here is suggesting that 12lbs needs to be available for unlimited times, but for the historically accurate times. Please see bug 174 in my sig......and vote for it :)

That base performing line B6 posted is 28mph slower at sea level than it should be for a spit running on 87 octane fuel at max power ie 6 1/4 Lbs, there is no 'boost' to add to it with that fuel, let alone the extra 25 mph at sea level that running 100 octane fuel and 12Lbs boost would get you.

I am genuinely intrigued by this, and not messing around, on what is that based?

I've seen this obviously, dated july 1940

http://www.spitfireperformance.com/spit2pnfs3.jpg

and as Crump has pointed out in the other thread that all Spit MkII's were using 100 octane fuel in June 1940.

So what have you got that proves they were only on 9Lbs boost during BoB?

Most know German data for test of serial production 109 E-1/E-3 claimed for 1.3 Ata (5-minutes emergency power) with 1/4 radiator open: 467-475 km/h.

http://www.wwiiaircraftperformance.o...109e3-1792.jpg

http://www.wwiiaircraftperformance.o...109E1-1791.jpg

And serial Swiss 109 E-3 corensponded very well with German charts above:

http://www.wwiiaircraftperformance.o...109E-Swiss.jpg

Hmm even with US test ( 290 mph at the deck)

http://www.wwiiaircraftperformance.o...e-109E3-US.jpg


So for serial 109 E-1/ E-3 speed at the deck for 1.3 Ata (5 minut emergency power) should be between 467-475 km/h

So i think 500 km/h would be really absolutly limit for serial 109 E version - if so it could be do at 1.45 Ata (1-minut emergency power) and radiator close for very short time ( below 1 minut).

Actually we will have it in incoming beta patch.

But looking at British fighters speed polars in beta patch there is not acurrate speed drop at lower alts even for 6 1/2 lbs power settings. Not mention there is lack of +12 lbs emergency boost which was significant adventage in low alts fights.

I read 303 Sqn pilots combat raports from Battle of Britain day's when they wrote about using +12 lbs boost in their Hurricanes MK1. It really make a difference at low alts fights.

Life must have treated you so unfairly, Osprey.