View Full Version : Tach & MAP gauges in IL-2?

03-06-2007, 01:40 AM

Now it seems that the engine gauges in many planes are totally screwed, but are there any that have them working correctly? I'm asking because I've this strange whim of doing some by-the-book flying (or at least approximation thereof) for a change http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

S! again.

PS. I think the IL-2 itself might have them in working order but I'm not sure - gotta check.

03-09-2007, 05:38 PM

03-10-2007, 10:45 AM
I hope that in BoB all the gauges work correctly.. and all the switches and levers are assignable.... it it is a function I hope to see it settable.. although I doubt tat will be the case.. since from what I have heard full engine startup procedures will not be possible.. but it would be good if there were multiple levels of CEM from none to you better not flood that engine if you want to get off the ground.

03-10-2007, 11:45 AM
Did Oleg really say full engine start-ups are impossible? I thought he said, they won't be implemented by Maddox Games. I sincerly hope, that 3rd party planes will have this feature and planes will finally be flyable by-the-book.
It sucks that one must start MSFS to have correct procedures.

03-10-2007, 12:46 PM
http://forums.ubi.com/images/smilies/agreepost.gif & that's for both of you guys... would just love to see this implemented myself too... S!

03-10-2007, 12:58 PM
Hi msalama

F6F Hellcat:
Take off: 2700 (100%) 50" (91%)
Climb and cruise: 2550 (95%) 44" (77%)
Best climb: 122 knots IAS
Economy Cruise: 2250 (75%) 34" (54%)
Combat: 2700 (100%) 52.5" (94%)

(Blower settings:
SL to 7000' (approx) : 44"
Shift gear when mp falls to 41.5" at full throttle (100%)

7000' to 18,000' (approx) : 49.5"
Shift gear when mp falls to 47" at full throttle.

18,000' to 22,000 (approx) : 49.5"
22,000' upwards : full throttle

As I recall, I took these from the manual, and they appear to work fine in the game, as do most of the other settings for other planes I've put together. Not bad, all things considered.

There's a terminal problem with MP and RPM guages?

03-10-2007, 03:01 PM
There are a lot of requests for realistic startup procedures, and picture perfect RPM/MAP/Fuel consumption/pitch/power ratios.

I don't understand it, really. I mean, it'd be cool and all if the engine startup was exact the same as the real engine, and if the gauges showed the exact correct numbers, but how could the developer possibly know these things? It seems difficult enough to find out the basic speeds and performance characteristics of a plane, never mind all the minutia of how the engine works in ever possible circumstance.

They would literally need their own authentic aircraft to test. And for each and every aircraft in the game!

And even if they did somehow get precise and comprehensive tables for these things (which probably don't exist for 1 plane, never mind 11), the game engine might not allow the combination of engine settings to give the correct result. The interrelations of throttle, MAP and pitch to create thrust are not linear, nor can it be expressed by any simple math.

I expect we'll still see the throttle % as a fraction of max power in BoB.

I would love to see realistic startup too, but I don't know how it would ever be possible given the scope of the game. The best one could hope for is some generic made-up switchology that covers every plane. Like WOV, people would say it's 'realistic', but really have little to do with engine starting.

03-11-2007, 04:12 AM

Thank you for your answers and opinions. The engine gauges are screwed in that they don't show correct values in relation to the MAP & RPM percentages in many planes. A good example is the Hurricane Mk.II, where - IIRC, haven't flown the bird for a while now - in order to maintain a cruise speed of some 140-150MPHIAS or so you have to constantly run it at +4lbs boost / 2000+ RPM, whereas the real thing cruised at 0lbs / 2000RPM yielding an airspeed of approx. 180MPHIAS.

Handsome: so the Hellcat has its gauges in order in relation to the HUD percentages? Thanks, have to try it out then http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Fritz: I see no reason to implement approximately accurate engine gauges in this game, too. Remember that f.ex. the MSFS series has had them for ages now...

S! guys. Good points and notions all http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

03-11-2007, 06:34 AM
The Hurricane MkII field mod happily hums along at 200 knots (230 mph) indicated at 16,000' (just under 5000 metres), stage 2 blower, +7 boost (77%), 2650 rpm (75%), which is the continuous operation limit set in the manual (I don't know if the actual speed is realistic or not).
I'd say that you can fly by the gauges in most of the planes, rather than in just a few of them.

03-11-2007, 08:22 AM
Ok Hand, then try to cruise the bastage at 0Lbs / 2000RPM - which IIRC is the recommended economy cruise setting - and report back please http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

03-11-2007, 08:45 AM
OK, tried it out myself just to be sure -

I loaded the v4.08 Hurri Mk.IIC up on the Crimea map and found out that 0 Lbs of boost corresponds with a percentual throttle setting of 22%. This setting is so low that the prop governor can't keep up anymore, so the resulting RPM was around 1800 or so. These power settings then resulted in my airspeed bleeding off to a point where I stalled out...

So something's a bit funny there I'd say. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

03-11-2007, 10:34 AM
Wow! This game can be such an eye opener!

The manual says: 13 ECONOMICAL FLYING (ii) Cruising:
"For maximum range fly in 'M' ratio (stage 1 blower, stage 2 being 's' ratio) and at maximum obtainable boost not exceeding +4 lb/sq.in. and reduce speed by reducing rpm which may be as low as 1,800, but check that the generator is charging... ...If at 1,800 rpm (or 2,000 if necessary)the speed is higher than that recommended, reduce boost. 's' ratio should only be used if at 2,600 rpm ('normal' cruise)the recommended speed cannot be obtained in 'm' ratio."

The recommended speed for a clean configuration is 160 mph (139 knots)

So if I've read that right, all things being equal:
For maximum Range
Use stage 1 blower
Use full throttle (not exceeding +4 boost)
Lower rpm to achieve 139 knots

At 16,000' again, 100% throttle in stage 1 blower shows +4 boost at 2600 'normal' cruise rpm, giving about 165 knots IAS.
Start reducing the rpm to slow down to the recommended cruise speed, and at 2000 rpm the manifold pressure drops to +1, with the speed holding (trimmed level) at about 136 knots IAS.

Not bad!

I think I've read all of this right...

03-11-2007, 10:51 AM
Ah-ha, I see... OK, gotta try that out myself as well. I'll report back later - tomorrow at the latest. S!

03-11-2007, 02:57 PM
The plot thickens... Here's maybe why cruising in the Hurricane is the way it is.

From 'Pilot's Notes General', 2nd Edition, 1943:

"The best I.A.S for range is, in general, the same at all heights; for the drag is least when flying at the best angle of attack, which is the same at the same I.A.S. at every height (at the same load)."

"For economical flying... the mixture control must be set to weak... If there is no manual mixture control, weak mixture will be obtained automatically by setting the boost at or below the weak limit." (+4 in the Hurricane II)

"In Merlin Engines the throttle valve cannot open fully unless the throttle lever is moved forward of the setting which gives maximum weak boost at the lowest altitudes. Therefore, at higher altitudes the lever must be set forward - up to the climbing position if necessary - in order to get maximum permissible, or obtainable, boost for economical cruising."

The Hurri notes clearly state 'maximum obtainable' rather than 'maximum permissible'.
Apparently, fuel consumption is significantly greater in 'S' ratio than in 'm' ratio.

At low altitudes, it's also apparently generally better to go with whatever higher speed is achieved with max. +4 boost and low rpm, rather than throttle back to the recommended speed. Specifically, for the Hurri, below 5000', 10mph should be added to the recommended speed.

Merlin engines... Same sort of thing for the Spit then, and the Mosquito, and the P51, and the Lanc (curses! No Lanc...)

I've no idea if all of this is intentionally modelled or what, but it's fun flying using settings like these.

03-12-2007, 02:00 AM
http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif Indeed. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Tried it out again as per the suggestions written out above and this is what I found out:

A prop setting of 20% w/ a throttle setting of 37% correspond with gauge readouts of slightly over 1800 RPM & 0Lbs which then - combined with some kinetic energy left over from the climb settings - gives you a cruise speed of about 130MPHIAS or so. So not that badly - if at all actually - off after all...

***EDIT*** Bearing in mind that this flight was conducted at a low altitude of approx. 3000ft. ASL! See my post below as well... ***EDIT***

At low altitudes, it's also apparently generally better to go with whatever higher speed is achieved with max. +4 boost and low rpm, rather than throttle back to the recommended speed.

Yep, this exactly is what got me there... ah well, so it's the man not the machine _again_ it seems http://forums.ubi.com/images/smilies/35.gif

Thanks m8 http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

03-12-2007, 02:02 AM
Manifold is before the air intake to cylinders and after supercharger.
In between is a plate that restricts air flow from manifold to cylinders.
That plate is controllable, it is the throttle plate.
And the gas changes with it.
Only there are interconnections between all of those specific to both engine and plane.
P-51 supercharger is not Spitfire supercharger as far as I read, neither is as Hurricane.
The engines of each may share interconnections but for sure not adjusted the same and
possibly not all of those are shared.
How much of that is a Merlin of Spit V share with Merlin of Spit IX that was not made for
fighters at all but Spit IX was long-nose adapted?

How many pilots in the war knew all these things beyond being exposed to them and not enough
time to absorb and practice them to where they automatically used all in coordinated fashion
even through the heat of combat? How many died sooner when mastering such things can be the
difference between veteran and ace? I see that only some players even care to know and my
hat is off to you guys! By compare I only fumble around mindful there is more I don't know
yet and maybe never will, so it is good to read threads like this one!

03-12-2007, 03:44 AM
Thank you for your interest Gunz http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif Yep, these things have always fancied me because there surely is more to these beasts than just flying around at max. RPM & flooring the throttle when one sees a dot in the horizon!

This test (? well more like tinkering with the machine truth be telt) were conducted down low, i.e. I took off from a grass field near Leningrad and climbed to approx. 3000 ft. ASL, so I'm not drawing any definite conclusions whatsoever yet before taking the bird to altitude for a longer flight. I also played around with the P-400, too, for a while and found out that a power setting of 32" / 2000RPM (corresponding w/ HUD values of 35% / 35% if memory serves) gave me a cruising speed of approx. 175MPHIAS down low - a reasonable ballpark figure I'd imagine for this bird.

Next on the list is the Rata of course http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif Bear in mind, though, that I'm definitely not attempting to get down to the nitty-gritty with this - ballpark figures are IMHO sufficient!

To be continued...

03-12-2007, 04:32 AM
Ah, and let's also bear in mind that all this tinkering should probably be carried out in standard atmospheric conditions as well before saying anything definite about, well, anything... Was it the Crimea map that had these?