Ki 84

[Krusty]

and if you stick a jet engine on a car you can get it to 300mph on land... ifs and what ifs are a terrible basis to model historic WW2 aircraft upon. Every other plane in this game uses historic WARTIME performance, not what-ifs and wishful thinking or unsubstantiated numbers. 427 is unsubstantiated in that it was only done on a post-war captured airframe with high octane fuel. The Japanese mostly barely had 87 octane at the end of the war.


Delayed EDIT follows:

Just to put some more nails in the 427 mph coffin (for the TL;DR crowd)

"Most "published" performance come from the TAIC manuals which are usually engineering estimates.  The fellow I talked to that was one of the engineers said that he didn't know of cases where actual data was incorporated into the actual TAIC Manual."

Somebody doing comparison math on other aircraft actually proven to meet 427mph:

"By the way, using other 'comparative' examples I've seen: the 363mph@S.L. speed would be quite normal for any fighter maxing at 427@@20,000ft, wheras, merely 325mph@S.L. would seem abnormally slow."

"in a perfect world, it would have.  But as things actually were, the Ki-84 never was able to realize these performance numbers."

I'd say that "perfect world" pretty much hits the nail on the head.

My father was 11 when WWII ended.  In 1945 he had been sent to live with relatives in Ibaraki prefecture NE of Tokyo.  In addition to going to school, he told me that he dug up a lot of pine tree roots.

Why?

To be used as raw material for turpentine to be used as aviation fuel.

It goes without saying that Hayates did not fly at 400 mph on mixtures including turpentine.

While you can play with the arguments within a certain range, you could say it was a little over 400, under 410 to be sure, that all depends no your arguments of whether you believe certain engines or exhausts were in use during certain tests, and ignoring the fact that prototype speeds are rarely met by heavily ladden combat production models, it could be even SLOWER still. Regardless of the wiggle room you care to play around in, the 427 rubbish is a TAIC computed estimate and was never actually tested. It was an estimate that got reproduced too many times. Like the MG151/20 cowl guns comment on the Bf109K-4 or the DB603G engines on a Me410. It just never happened, based on the finer details and facts available.

[morfiend]

WRONG!!! Ki84 does not shed until about 475...I have flown it for many many years....Also I read somewhere that the ki84 was capable of keeping speeds with the p51D......

  The Ki84 will shed parts at 475 without pilot inputs but get her above 430,say 435/440 and pull on the JS see what happens!


  Not that it matters much because as someone already said a faster KI wont make anyone a better pilot!


  YMMV.




   

PS: I have read many times that when allied pilots saw them over fly they were told"thats a frank dont bother trying to chase it"!   Much like the mossie it was fast enough that to chase it would mean you would never catch it! Which makes sense because climbing up at about 170 mph to catch a plane doing around 400 mph just doesnt make sense.

[Devil 505]

Krusty, the problem as it pertains to AH is that no other plane is handicapped based on "lack of optimum fuel". Is the 109K-4 or TA-152 limited because of the rarity of C3 fuel? I think not.

Every other plane is rated as close to intended factory performance as reasonably possible.

[Krusty]

Devil, that's a false argument to make. Overall the situation with Japanese engine performance was so bad, so deplorable, that a large number of them actually crashed into the trees at the end of the production plant runway, and those that made it to units couldn't be sure that if they could take off at all they'd be able to stay with the rest of their unit and even climb to the enemy. It was BAD. Very bad. Actual wartime combat power was very low. What we already have is the BEST case scenario. We have the early version of the Ki-84-Ia, which had the best reliability and the best performance numbers. The later production batches were so bad that the Ki-61 was more reliable than them.

Furthermore, Bf109K4s and Ta152s had C3 gas. They flew combat sorties on it, using it to its full potential, and making full power during that use. Japanese fuel was just part of the equation, but it had impurities mixed in it, thinners added and other things that made it knock and detonate at very low manifold pressures. It could never make 427mph on the Ki-84 airframe and engine, not with the utter shambles of production quality at the time. We actually have a version in AH that was probably better than 90% of all Ki-84s ever produced or flown. Not just in reliability (though I have a BONE to pick about shedding of control surfaces at an absurdly low speed!!!!), but in speed as well. Much like our Bf109K-4 is an ideal version, with the best finish and smoothest construction. Many were built roughly at the end of the war and the speed range could vary based on finish, assembly, and gaps in surfaces. We have the same "ideal" wartime performance of the Ki-84, but it is that. It's wartime performance.

[Karnak]

All Japanese planes are modeled using Japanese performance numbers and, thus, crappy fuel.

All Allied planes that used 150 octane later in the war are modeled using 100 octane for balance purposes.

The Bf109K-4 couldn't fly on anything other than C3 so there isn't an option, nor would it be realistic, to model it on poorer fuel.

I am more suspicious of the shedding parts aspect of certain aircraft, including the Ki-84.

[Devil 505]

Krusty, it is your argument that is false. No other plane has manufacturing defects or common engine reliability issues modeled in to their game design - otherwise, Me-163's would be frequently exploding on takeoff and B-29's, Me-262's, and Ar-234's would have their engines burning up often as well.

The defects seen in the Japanese manufacture are the result of manufacturing under the strain of frequent bombing of factories and other infrastructure along the supply chain - just as Germany suffered. It's not like the engines were being built to run poorly on purpose.

Furthermore, if the aircraft tested postwar by the U.S. was a combat aircraft when captured, then I am of the opinion that the test would accurately represent the actual performance of a well built airframe. Remember that a fuel's octane rating is referring only to it's ability to resist predetonation, it has no power boosting effect on it's own. The HA-45 engine was designed to run with 92 octane or higher, thus the 100 octane U.S. fuel would make no difference on a 92 octane rated engine.

The Bf109K-4 couldn't fly on anything other than C3 so there isn't an option, nor would it be realistic, to model it on poorer fuel.

The HA-45 was not designed to run on anything less than 92 octane either - but it was out of necessity. And a DB605 could run on a lower octane fuel than C3(93 octane) - only poorly - just as our Ki-84 is modeled.

[Karnak]

Devil,

The Ki-84's unreliability isn't modeled.  The engine generates full power at all times.

Also, as noted, all Japanese aircraft are modeled to Japanese test results.  The N1K2-J has the same engine as the Ki-84 and only makes 369mph at max.

[bozon]

if the ki84 is modeled to top imaginary performance of 427mph, I want my Mossie VI rated at the very real +25 boost to make KI84 players weep.
 

ps,
that is +25 boost to both engines

[Mister Fork]

Are we limiting Japanese plains on their performance due to poor fuel and not German planes?

[Lusche]

Are we limiting Japanese plains on their performance due to poor fuel and not German planes?

AFAIK the German planes in game are using the power setting and fuel grades available for them in RL. They didn't suffer from poor fuel as such but generally from not having enough. Each german plane in game has a performance level which mirrors actual german flight testing and operational procedures.
The Japanese had much more quality problems (not limited to fuel, either).

[Karnak]

The only aircraft that are restricted to using less than their best available fuel, so far as I know, are the Allied aircraft that used 150 octane by the end of the war but in game are using 100 octane.  This is reasonable for balance purposes as it would make horrible monsters out of the P-47s, P-51s, Mosquitoes, Spitfires and Tempests that used 150 octane.

[JunkyII]

I always found that 360 is the cut off for speed I want to enter a fight at as far as maneuvering...if I'm going faster I'm zoom climbing to shed some E before starting more angles.

I just want to see the KI84 updated....

 

[FBKampfer]

It was BMW 801's that needed the synthetic C3 100 octane fuel. The DB 605's, 603's and Jumo 213 could both run on either C3 or the refined B4, though as the B4 was reliant on oil, quality issues did pop up towards the end of the war, mostly related to engine fouling, rather than any significant drop in octane rating, though still resulting in a loss of power.

However the Luftwaffe's jagdgeachwaders and to a lesser extent the panzerwaffe had top priority on fuel, so they typically got the best of what was available. This would have mitigated the problem to some extent, but it's still interesting to consider.

[Lusche]

AFAIK the German planes in game are using the power setting and fuel grades available for them in RL.

A short article on that:  http://gasolinefuels.blogspot.de/2011/06/world-war-ii-and-octane-ratings.html

After the war, the US Navy sent a technical mission to Germany to interview German petrochemists and examine German fuel quality. Its report entitled “Technical Report 145-45 Manufacture of Aviation Gasoline in Germany” chemically analyzed the different fuels, and concluded that “Toward the end of the war the quality of fuel being used by the German fighter planes was quite similar to that being used by the Allies.”

[bustr]

Here is the link to the NAVY document.

http://www.fischer-tropsch.org/primary_documents/gvt_reports/USNAVY/tech_rpt_145_45/rpt_145_45_toc.htm