Huricane Mk I 100 Octane perormance tests 1.07.18301

[Igo kyu]

Originally Posted by klem

Just did a quick comparison of Hurricane Mk I 87 Octane vs 100 octane at 1000, 5000 and 10000 feet.

Seems the old 87 octane is faster than the 100 octane

Your figures are without boost. The difference was AIUI (which may or may not be correct ) that 100 octane allowed more boost at low level. So figures without boost shouldn't show a difference, and with boost only up to FTH.

[Bounder!]

Originally Posted by Igo kyu

Your figures are without boost. The difference was AIUI (which may or may not be correct ) that 100 octane allowed more boost at low level. So figures without boost shouldn't show a difference, and with boost only up to FTH.

I think that's precisely the point (or problem) that there shouldn't be a difference ingame between the 87 and 100 octane without boost but there is. All I hope is that the devs had said that the FM were still WOP and so data like this is good as it can highlight problems with the current ingame FMs.

[Igo kyu]

Originally Posted by Bounder!

there shouldn't be a difference ingame between the 87 and 100 octane without boost but there is.

There will be variations between runs at exactly the same settings (unless they are flown by utterly flawless autopilots). If the variation between runs with different settings is in about the same range as the difference between runs with the same settings, then that's the best that can be expected, and that graph looks as if it might be the case. If more tests show similar variations between runs at the same settings, it's probably alright, if with the same settings you come up with identical numbers time after time, and there is a significant (in the technical statistical sense) difference between settings, then there might be a cause for concern.

I shan't bother to do any testing myself.

[Bounder!]

Originally Posted by Igo kyu

There will be variations between runs at exactly the same settings (unless they are flown by utterly flawless autopilots)....

Oh absolutely and the difference in the graph between 87 and 100 tested in game appears small - repeat tests may well show the difference is due to random variation between tests rather than a real difference between the models in game. Perhaps I misread your post, I was merely pointing out that there should not be a real difference between 87 and 100 octane without boost.

Something that does seem off in the Spit 1a 100Oct vs 87Oct is engine overheat, particularly in the climb and at altitude (not using boost) where the Spit 1a 100Oct is far more sensitive to overheating and so I find I have to use lower power settings in the 100Oct version currently than in the 87Oct version. I haven't done much testing in the Hurricane versions but it wouldn't surprise me if it was a problem here also. It's important to have people testing the new FM as they are WIP and so they can be modeled properly and it's great that people are doing so.

The big cause for concern at the mo is the difference between the modeled ac and rl performance which is off in both the Spit 1a and Hurricane, I haven't seen much data for the 109 but would love to as it's important that all aircraft in game are modeled as accurately as possible and it may well turn out that the 109 is also suffering under-performance.

[Crumpp]

But Seadog, Crumpp says the Pilot's handbook says nothing about 12lb boost.

No Milo,

I said the Notes on a Merlin Engine does not list 100 Octane as the specified fuel. That points to the extent of use and service.

By January 1942, 100 Octane was common enough for the Notes on a Merlin Engine to distinguish 100 Octane as the fuel for operations and 87 Octane for training.

I can see why you would be confused.

[Seadog]

Originally Posted by Crumpp

No Milo,

I said the Notes on a Merlin Engine does not list 100 Octane as the specified fuel. That points to the extent of use and service.

By January 1942, 100 Octane was common enough for the Notes on a Merlin Engine to distinguish 100 Octane as the fuel for operations and 87 Octane for training.

I can see why you would be confused.

The extent of use and service is pointed to by the expenditure of thousands of tons of 100 octane fuel, numerous RAF documents stating its use during the BofB, numerous combat reports, and pilot accounts of 12lb boost and a complete lack of evidence of the same for 87 octane...but this is an argument long past now.

This issue now is that 87 and 100 octane performance in CLoD is completely FUBARed.

[TomcatViP]

Originally Posted by Seadog

The extent of use and service is pointed to by the expenditure of thousands of tons of 100 octane fuel, numerous RAF documents stating its use during the BofB, numerous combat reports, and pilot accounts of 12lb boost and a complete lack of evidence of the same for 87 octane...but this is an argument long past now.

Tht's only your interpretation. It wld be more honest to point it in the right manner.

As for an example and as already said, an article of "Flight" reviewing just after the war's end and written at the occasion of the Merlin anniversary list all Merlin version with the type of fuel used. It does not state any Fighter powered with Merlin using 100oct before 41/42.

More can be said of course. But if all this has been alrdy written it does not mean that it could be swapped out like you did summing it up.

And frankly thinking seriously about it I wonder how you can imagine that a fighter aircraft designed to be operated above the cold seas of the Channel and the North sea would have seen is fuel swapped with as much technical care as a Ford Hotrod boosted for the quarter mile.

[Al Schlageter]

Originally Posted by Crumpp

No Milo,

I said the Notes on a Merlin Engine does not list 100 Octane as the specified fuel. That points to the extent of use and service.

By January 1942, 100 Octane was common enough for the Notes on a Merlin Engine to distinguish 100 Octane as the fuel for operations and 87 Octane for training.

I can see why you would be confused.

It is like this Eugene: no 100 octane fuel, no 12lb boost.