SPIT MK I/II and over boost

[Osprey]

Originally Posted by 41Sqn_Banks

The point is the following: If you use 87 octane fuel you are not allowed to apply a higher boost than +6.25, if 100 octane fuel is used the maximum allowed boost is +12.

Thus 100 octane fuel doesn't give you more power directly, however it allows you to apply more boost - which will give you more power.

Exactly, and I even spelled that out for him in the reply which he then quoted. Wierd.

[TomcatViP]

Juts to remind the expert here that the Spit I/II (especially the II) hve UFO flight model for now.

They can run away if you dive on them
Past you at 450 and turn 180 to engage the fight that you want to deny running flat out straight
Turn indefinitely at 90 bank angle
Hve a nose up attitude that will make shy a dolphin in a marine park (yuck yuck)
ETc.. etc..

Let's start at the beginning. 100 octane fuel was not candies FC give away to Fighter pilots !

[Kurfürst]

Originally Posted by fruitbat

Which by the way don't tally with your dates, mine are from there own ops book, where are yours from?

Hi, they were simply copied over from the RAF.mod site. I guess some differences are possible.

[CaptainDoggles]

Originally Posted by 41Sqn_Banks

The point is the following: If you use 87 octane fuel you are not allowed to apply a higher boost than +6.25, if 100 octane fuel is used the maximum allowed boost is +12.

Thus 100 octane fuel doesn't give you more power directly, however it allows you to apply more boost - which will give you more power.

Yes, this is true. But you can't just "apply more boost" unless the engine has specifically been designed to allow it. If your engine only has enough compression ratio to make use of 87 octane you will need to make modifications.

[CaptainDoggles]

Originally Posted by Osprey

Exactly, and I even spelled that out for him in the reply which he then quoted. Wierd.

Yeah but it was couched in a bunch of nonsense about 1946 and il2compare that I really couldn't care less about so I probably only half-read your reply.

[Osprey]

Originally Posted by CaptainDoggles

Yeah but it was couched in a bunch of nonsense about 1946 and il2compare that I really couldn't care less about so I probably only half-read your reply.

But you quoted it. And now you're saying it's nonsense but you only half read it....probably.

Make up your mind CD, don't comment on it if you haven't followed the context.

[Faustnik]

Originally Posted by CaptainDoggles

nonsense about 1946 and il2compare.

I use HSFX5 IL-2 as well as CoD. HSFX5 Compare looks pretty good. Spit 1 looks like 87 oct and Spit IIa looks like 100 oct. There is a early Hurri 1 with 87 oct and a later Hurri 1 +12 oct. HSFX5 is a not nonsense.

This is what I was trying to say before, 1940 should have different versions for 87 oct amd 100 oct. Hopefully CoD will have Spits and Hurris with several versions. You can't just say that all 1940 Spit and Hurris used 100 oct, and you can't say that all used 87 oct.

[Al Schlageter]

Originally Posted by Faustnik

I use HSFX5 IL-2 as well as CoD. HSFX5 Compare looks pretty good. Spit 1 looks like 87 oct and Spit IIa looks like 100 oct. There is a early Hurri 1 with 87 oct and a later Hurri 1 +12 oct. HSFX5 is a not nonsense.

This is what I was trying to say before, 1940 should have different versions for 87 oct amd 100 oct. Hopefully CoD will have Spits and Hurris with several versions. You can't just say that all 1940 Spit and Hurris used 100 oct, and you can't say that all used 87 oct.

Not very smart of the British to not use 100 octane fuel when they had so much of it in an region where it was definitely required.

The only concern should be the RAF bases that are on the CloD map.

[41Sqn_Banks]

Originally Posted by CaptainDoggles

Yes, this is true. But you can't just "apply more boost" unless the engine has specifically been designed to allow it. If your engine only has enough compression ratio to make use of 87 octane you will need to make modifications.

Below full throttle height every supercharged engine has more boost available than allowed. The problem is to prevent the pilot from applying more boost than allowed by mistake. The boost control does that. The Merlin engine has a provision to disable the boost control (so called boost control cut-out).

[CaptainDoggles]

Originally Posted by 41Sqn_Banks

Below full throttle height every supercharged engine has more boost available than allowed.

Sure, but this isn't because of the fuel. That's all I'm saying.

The reason higher boosts aren't allowed is because the fuel will ignite prematurely, usually before top dead centre and at best this saps your available power. At worst it will wreck the engine.