ki84 speed????

[Ack-Ack]

"what we have here is plainly that no axis ride will ever be modelled faithfully if it is superior in performance to an allied model. hence the flap BS and so forth.  Storch"


 

Flap B.S.?  Do you realize that the auto-retracting flaps has the most negative impact on the P-38 which is an Allied plane?  Time to readjust your tin foil hat.



ack-ack

[Karnak]

Originally posted by TequilaChaser
Karnak,
Do you feel like with out the speed you do not have an equal chance of being competitive?

Because everybody runs away unless in a horde and if it is a horde I am not good enough to fight them all, so I need enough speed to try to survive.  The Mosquito, an aircraft that was renown for its speed, is slow as molasses here and I'm sick of having the chicken****s either run from me or gangbang me.

I was hoping the Ki-84 would narrow (not eliminate) the speed disadvantage and provide a platform that was also reasonably manuverable for fighting, something the Mosquito is poor at.

As it turns out the Mosquito is better at manuvering than the Ki-84 and is faster than the Ki-84 and massively outguns the Ki-84.  In summary, the death trap Mosquito looks downright easy and safe compared to the Ki-84.  I'd be better off switching to the N1K2.  It still can't survive, but at least it can fight back before it dies.


It feels like I am 0 and 8 or so in the Ki-84 as I post this.  I have hit the ground so many times it's not funny.  It stalls out as bad as the Mossie, it gets heavy on the elevators worse than the A6M.  I haven't been abble to dodge anything in it.  Everything that I've tried to fight I could never get anywhere near gunnery range and it is incradible fragile.  The Mosquito is incredibly easy comparitively.  Of the two fights I've had in the Mossie tonight I won the one against a P-38L and lost to an La-7.  In both cases I was heavy with bombs.  I can't win a fight in the Ki-84 without bombs.


Kweassa,

You underestimate the Mossie.  It is true that a co-alt fight is a bad thing for it, but it can do a lot with a little altitude and it dives like an anvil and maintains controlability the whole time.  I have won some insane fights in it, and it is the only aircraft I've ever gone more than 15 and 0 in a row with.  I got 31 kills in the Mossie before colliding with a Spitfire that I was trying to make victim #32, and no it wasn't an HO or front quarter shot.

The problems the Mossie has is that it is slower than crap, a huge target and everybody knows it so they want the free kill.  Most Mossie drivers don't even try to fight.

[Kweassa]

Hmm..

 What engine does our Ki-84 use anyway?

 Is there any possibility that our Ki-84-Ia does use the Ha-45-21, but doesn't use the WEP?

 This is all very confusing.

 If the early Ki-84s with Ha-45-11 had already recorded 392mph, then wouldn't they have reached that speed with some kind of WEP engaged?

 Or, does it mean that the early Ki-84s with a 1800hp reached 392mph max speed with just military power?

 Then, how fast are they supposed to be with WEP?

 
 So my questions are;

1) how fast is the Ki-84 with Ha-45-11 on military power only?

2) how fast is the Ki-84 with Ha-45-11 with emergency power engaged?

3) how fast is the Ki-84 with Ha-45-21 on military power only?

4) how fast is the Ki-84 with Ha-45-21 with emergency power engaged?

5) how do we know our Ki-84 has the Ha-45-11?

[JB42]

Wasn't the Ki-84 a high alt fighter?

[Wotan]

What engine does our Ki-84 use anyway?

Ha-45/11

See Mitsu's post and graph.

HA45-SP means HA-45-Toku (Special in English), aka HA-45-11.

Is there any possibility that our Ki-84-Ia does use the Ha-45-21, but doesn't use the WEP?

Nope, the Ki-84 in AH2 is an early Ki-84 with a Ha-45/11 engine.

If the early Ki-84s with Ha-45-11 had already recorded 392mph, then wouldn't they have reached that speed with some kind of WEP engaged?

No, you are only talking 4 mph. The AH2 Ki-84 has a max power setting at 250mmHg @ 2900rpm. (standard maximum speed).

Or, does it mean that the early Ki-84s with a 1800hp reached 392mph max speed with just military power?

Actually from what I read the 1800hp was take off power running at 400mmHg @ 2900 rpm.

At 250mmHg it should have less then 1800hp.

AIREVIEW's General View of Japanese Military Aircraft In ThePacific War, Vol.1,pg.320:

Ha-45/11 NK9-B(IJN-nomenclature)
HP(T.O.): 1,800 @ 400mmHg & 2,900rpm
HP(2,000m/6,562-ft): 1,650 @ 250mmHg & same-rpm
HP(5,700m/18,701-ft): 1,460 @ 250mmHg & same-rpm

The Ki-84 as modeled in AH isn't mis-modeled. It hits the numbers it's supposed to (for the most part). Karnak is questioning why model a Ki-84 with a Ha-45/11 and not a later war Ki-84 with a Ho-45/21 and water methanol.

Most likely the answer is that HTC went with the data they have.

Then, how fast are they supposed to be with WEP?

Wep is mis-leading. You want to know what was the highest possible mmHg that the Ho-45/11 could run at and its time limit.. ie emergency power.

Take off power as I quoted above and have read else where is 400mmHg @ 2900hp. In AH the Ki-84 max power setting is 250mmHg @ 2900rpm.

The 388 mph (624 kph) figure is for "standard maximum speed" at +250 boost.

Clearly the Type 4 fighter could fly faster than 388 mph if the pilot increased power above +250. The question then becomes, how much faster. The manual doesn't answer that question.

HTC has data for a 250mmHg @ 2900rpm Ho-45/11 and thats what they modeled it.

1) how fast is the Ki-84 with Ha-45-11 on military power only?

288-392 mph (this could be max allowable boost for this version)

2) how fast is the Ki-84 with Ha-45-11 with emergency power engaged?

I don't think any one has come up with that data. As Pyro said:

The WEP issue is a confusing one. Busa has been doing a lot of research for me over in Japan on the N1K and also the Ki-84. It's not very clear-cut as the engine had various restrictions placed upon it at various times and the IJA and IJN did not treat the engines the same. His research leaned toward the Ki-84 not making use of WEP while the N1K did, but again, it is not a clear-cut situation and is the source of much debate.

Busa and Fdutchmen are looking into it.

If take off power is @ 400mmHg then clearly the Ki-84 could run about 250mmHg. The question is how much and how long and how much of a speed gain do you get..

3) how fast is the Ki-84 with Ha-45-21 on military power only?

about 410mph

4) how fast is the Ki-84 with Ha-45-21 with emergency power engaged?

Well at maximum boost and water methanol about 420mph (see the US test with 100 octane avgas)

5) how do we know our Ki-84 has the Ha-45-11?

Because that�s the most prolific data. And by comparing the power settings.

The AH2 Ki-84 is for an early version with a Ho-45/11.

[Wotan]

Frank's Top-Speed:388 or 427mph...):Case Closed?

[humble]

Karnak...

We must be playing a different game. I have no problem finding some decent fights...obviously the horde is an issue at times but not always. As for the mossie its a marginal plane unless you have alt & E...basically you have to fight it from the advantage. It seems to me from your comments that your primarily focused on fighting from "the perch" Tiffie/D-9/109-G10/P47-40/P51 are all primarily E fighters...simply seems you want a plane that can outrun and outturn almost anything in the game....gee we have that already...its called a Yak-9U.

[Karnak]

Humble,

If the Ki-84 had a top speed of 392mph and a top deck speed of 345mph I'd have been satisfied.  That is hardly faster than everything in the MA.

This 323mph is just too hard to get over.  The high speed handling that is as bad as an A6M is kinda shocking too, as is it's fragility.

[busa]

Hello, all.

I want to give easy explanation about the performance of Ki84.

I submitted the official performance of Ki84 to Pyro.
The maximum speed is not <583km / 6000m>, and <631km / 6120m>.

Japanese planes are carried out performance measurement by Military power.

The engine which Ki84 installed is equipped with water methanol injection.
But Japanese engine of WEP is not related to water methanol injection.
The equipment operates automatically by MP higher than normal power.

There is no WEP of Japanese engine with output increase equipment.
It is an operation concept.

WEP was enacted in IJN in October, 1944.
But there are no data of having enacted WEP by IJA.
Also in the same engine, in IJA and IJN, operation restrictions differ in many cases.

I also proposed a possibility that takeoff power could be used for 1 minute.
But I think that this was equally treated by HTC with other airplanes without WEP.

The engine which KI84 installed is neither Homare21 nor Homare11 (Ha45sp).
The engine is Homere21 with documents.
But special operation restrictions are carried out.
The performance of the engine is completely the same as Homare12 (NK9 H-B).

The performance is as follows.

1820H.P. of takeoff power. (MP+350 RPM2900)
1670H.P/ 2400m of military power. (MP+250 RPM2900)
1500H.P./ 6550m of military power. (MP+250 RPM2900)

Ki84 prototype was installing Ha45sp with documents.
But the prototype of IJA installs the engine which is not usually government-issued supplies.
Ki84 prototype also had the engine which the development department assembled specially installed.
I concluded that the engine of the prototype of Ki84 was unknown.
The reason is because the prototype carried out performance measurement by MP+350 RPM3000.
These operation restrictions are the same as Homare21.
And the altitude which carried out performance measurement is too high for Ha45sp.
This fact is contradictory to the reduction ratio of the supercharger of Ha45sp.

The early production model of Ki84 may have installed Homare11(Ha45sp).
But the early production model  of Ki84 may have installed Homare21 (Ha45).
The reason is that IJA tended to operate this engine by MP+350 RPM3000.
However, MP has not increased to +350.

Finally on documents, the engine which Ki84 installed is Homare21 (Ha45).
But operation restrictions were made the same as Homare11 and Homare12 (NK9 H-B) around April, 1944.
This fact can be checked till around April, 1945.

Ki84 in AH is installing Homare12(Homare21 derated engine).
Ki84 of a genuine article is installing Homare12 (Homare21 derated engine).
The prototype of Ki84 demonstrates 624 km/h by MP+350R PM3000.
Ki84 of AH demonstrates 624 km/h by MP+250 RPM2900.
This thinks that it is never the performance reduced unfairly.

These investigations are conducted based on the manual of N1K2-J, the manual of Ki84, the manual of Homare, INTERMIM REPORT NO.2, other manuals, and related 80-volume books of grade.

And even now, investigation is continued.

By the way,  The climb rate of Ki84 greater than official performance now.
Isn't this thing more serious?

To FDutchman
I have translated the data of WEP, Homare, Ki84, and others.
Since other data were too extensive, I had you help.
It will be my responsibility if a defect is in data.
Thank you, FD.

I want my translation software to do good work.

Thank you all.

[Zanth]

Originally posted by busa
By the way,  The climb rate of Ki84 greater than official performance now.
Isn't this thing more serious?

I agree with you.  I am surprised this has not gathered much attention.  KI84 as currently modelled is among the best climbing of aircraft in the game.  The rate of climb is something more than the rate of climb gauge is able to display (which is to  say the aircraft's guage is buried at maxium reading - struck me as odd at the time - but I am not studied in this).

[Karnak]

Thank you for your efforts Busa.

I did note the climb performance, but I think people are overstating it a bit.  To me it is only off by a two or three hundred feet per minute, not the thousand feet per minute that some claim.


Is the top sustained sea level speed of the Ki-84 correct at 520km/h?  That seems very slow to me.

What about the exhaust ejector stacks that were added to the later prototypes and the production models?  Did your data mention them?

Last I wonder if you have data about the Ki-84's poor roll rate and elevator heaviness.  It is surprising that the IJA would except an aircraft for service in 1944 that is as bad as the IJN's 1940 A6M fighter in regards to control heaviness.

I had understood that the Ki-84 represented a recognition by the IJA command that speed was required for modern fighters.  If the flight model in Aces High is correct that cannot have been so as the Ki-84 is incapable of attaining or fighting at medium and higher speeds.

[Mitsu]

I think everyone is confusing about definition of the War Emergency Power.
Running the engine at over-boost is also WEP.

IJA Ki-84 Flight Manual by P-kun shows example:

Engine "Ha45-21" r.p.m/ manifold pressure
   Emergency(1 min):      3000rpm/+400mmHg
   Militery(30Min):      2900rpm/+250mmHg
   Normal Max(long time):      2000rpm/+100mmHg
   Crusing:         1800�`2000/-100mmHg�`-200mmHg
   Permission maximum(30sec):   3200rpm/-200mmHg

[Mitsu]

Karnak, as you know, this is the TAIC Ki-84's speed curve graph. The leftmost graph is recorded at the lower military power (around 1800HP at SL).

it fits HA-45-11's power curve too. So we can suppose the Ki-84 performance which had HA-45-11 from it.
324mph at SL, it is not strange.

[Mitsu]

I love current AH Ki-84, but I hope to equip true HA-45-21 engine to Ki-84-1-Ko to get a clear-cut answer (luckily, we have TAIC Ki-84 data to simulate HA-45-21 engined Ki-84).

Over 3000 Ki-84s are built in RL. At least one hundred Ki-84-Is equipped with HA-45-21 engine like a N1K2-J in the late war, didn't they? Oh well, at least Ki-84-I-Otsu recorded 660km/h in the flight test in the late stage of the war, Japanese researchers are thinking it is highly possible that its Ki-84 is tested with HA-45-21 engine.

[Pyro]

Mitsu, the problem with the TAIC performance is that it was just an early estimate of what this new plane could be capable of doing and provide some intelligence to commanders and pilots.  A blurb that accompanies this performance states:

"Drag analysis is based on areas and dimensions and the assumption that the plane will have lines similar to OSCAR.  Dimensions given are similar to those of OSCAR and it is quite certain this plane is of Nakajima design.  Performance figures should be taken as estimates but they do give an indication of the expected performance of new Japanese fighters."

Busa, thanks for your help.  I'll have to take a look at the climb rate.  It may be that it's not falling off fast enough with altitude.  

As far as the takeoff power, I left it out under the impression that it was restricted from use.  That's what I still have a point of confusion about.