difference between the spitVb and the spitLF V??

[IceFire]

Originally Posted by illegalBeagle

Unless I'm mistaken, I don't think the original question has been answered. My understanding is that the games Spit Mk Vb without the LF or HF suffix is supposed to represent a slower Spit exported to USSR using less powerful Russian fuel. Someone correct me if I'm wrong here please.

Swiss answered it... simply the F is the medium altitude (regular) model while the LF models are optimized for low altitude flight and the HF model is for high altitude.

With the Mark Vb it's a bit more confusing because the modeling also represents different years. So ... we have different engines with different supercharger settings and then you throw in the clipped wing versions too (which have an overall performance impact).

The Vb has RAF level performance for 1941 (actually I believe it's a bit better than it should be in the climb). The VVS didn't receive lower performing models... although by the time they got them and employed them performance may have been lower due to lower quality field conditions (fuel, oil, dusty conditions, etc.). The Spitfire was a bit more sensitive than some of the Russian birds. This doesn't seem to be represented in the game.

So to recap: The regular Vb has higher performance at higher altitude while the LF.Vb has higher performance at lower altitude and drastically reduced performance at higher altitude.

Spitfires are confusing because there are many modifications made to them over the time that they were used and not all of these are represented by a model number change. In comparison to the Bf109 we have the G series with G-1 through G-14 each representing some sort of significant change. With the Spitfire they would probably have been all under one Mark number with very little to identify. The RAF was slow to even classify the modified aircraft (some publications and log books refer to the Mark IX-B which is really a Mark LF.IX ).

Confusing

[illegalBeagle]

Fuel quality is the issue I mean, not derated engines. My understanding is the first Spit we got for this game, the MkVb, was intended for Eastern front maps in USSR service not Western theater. Lower quality Russian fuel resulted in lower performance, and this is modeled somewhat. For years the game was primarily Eastern front. This is from years ago and my memory is fuzzy.

[David198502]

hey thx to all of you guys.but now im curious.swiss where do i get this il2compare tool???

[Kwiatek]

Octan fuel is very important for engine performance. British used 100 octan fuel before BoB time in their Merlin III engines which allowed to got more boost preassure - 12 lbs instead 6 1/2 lbs ( for 87 octan fuel). These significantly improved low alt performacne (below FTH) of Spitfire MK 1 and Hurricane Mk1. ( I wonder if it would be correctly moddeled in Oleg BoB?).

So Merlin III engine ( Spit MK1 and Hurricane MK1) with 100 octan fuel changed boost preassure for engine ----> 9 lbs - Max. for climbing (normal rating)(1 hr. limit)
and 12 lbs - Max. for all-out level in special emergency ( climb and combat 5 min limit).



Spitfire MK V initialy appeard with Merlin 45 engine. Normal rating was + 9 lbs ( 1 hour). The question is if it was allowed from the begining emergency rating +12 lbs? I got manual for Spifire MK II with Merlin XII engine and there were +9 lbs - normal rating and +12 lbs -emergency rating. I got also manual for Spifire MK VA-B-C with MErlin 45,45M,45, 50,50M,55,55M engines. There is ratinging for engines:
+12 - take off,
+9 - normal ( max climbing 1 hr limit),
+16/+18 - emergency combat 5 min limit ( +18 is for M engines - low alt)

These manual is rather late version for all type of Spitfire MK V and engines. I dont have early manual only for Spitfire MK VA and VB with Merlin 45.
Still i think that Merlin 45 like any other Merlins with 100 octan fuel ( like MerlinIII, Merlin XII, Merlin XX or late Merlins 61,66, 70) has both normal rating ( +9) and emergency rating ( +12). Later in 1942 year emergency rating for Merlin 45 was rised for +16 lbs and for Merlin 45M ( crop supercharger - LF version) for +18 lbs rating. Shortly speaking Merlin 45 was standart Spit MKV engine, Merlin 46 was for higher alt supercharger settings and engines with "M" like Merlin 45M or 50M was with cropped supercharger for low alts.



If we speak about VVS Spitfires and any other lend lease western planes like Hurricanes, P-40, P-39 and others these all planes need for full performance 100 octan fuel. Probably Russian used only 87 octan fuel which casue derated performacne of these planes and lower boost preassures. Thats why Russian opionion about such planes wasnt positive. Some Russian planes have similar performacne with lower octan fuel.

[swiss]

Originally Posted by David198502

hey thx to all of you guys.but now im curious.swiss where do i get this il2compare tool???

http://ultrapack.il2war.com/index.ph...3.0;attach=956

[David198502]

thank you very much swiss!!!!

[swiss]

no problem.

Are you already registered on sturmovik.de?

[David198502]

ähm yes why???