Ki-84 performance data

[Vermillion]

TAIC reports were issued at various times, and peridodically updated throughout the war as more information became available.  The biggest problem with the Planes of Fame book is that it doesn't provide the date of which reports its using.

The Ki-84 tests were not done at Clark Airfield, they were performed at Dayton Ohio at Wright Patterson Airforce Base, and in Pennsylvania at a airfield who's name escapes me at the moment (I'm at work and all my resources are at home).  This is a subject I've done quite a bit of research into.

[butch2k]

Verm the March 1945 version i have seems a bit more complete than the one in the plane of fame book but the data is revision A so i'm a bit at a loss.

[gripen]

Vermillion,
The Ki-84 was tested at Clark field, this is well documented in several sources (actually two examples were tested there at spring 1945, TAIU-SWPA numbers S10 and S17).Check for example "War Prizes" by Phil Butler. Also some primary sources on these tests are easily available if you mind to do some work...

gripen

[brady]

Help me out here gent's, we have a slugish N1K2-J, the Ki 84 has the same engine, won't we have a slugish Ki 84?

[Vermillion]

Easily available?  You must know something I dont.

I have been in contact with the US Air Force Musuem several times concerning the flight test data for both the N1K2-J and the Ki-84 (both of which were tested  there at Dayton). On the telephone, by email, and by letter.

I talked directly with a guy named Menard, who was the chief researcher at their data archives.  He told me that according to their records and he said he also talked directly with several of the leading authors/historians/researchers in the US on Japanese aircraft.  

Basically according to him, the data for those planes just doesn't exist anymore.  He told me its commonly requested though.

Maybe he's full of it, but I know he's helped me and several other members of the AW/WBs/AH communities find quite a bit of flight test data in the past on other aircraft.  He retired within the past year or so though.

I made similar data requests of the US Naval Aviation Musuem (they have the only other existing N1K2-J, beside the USAF Musuem) but I never got a response from them.

I haven't contacted NASM yet, but I do have a contact person there.  I just got busy, when my life got turned upside down, while I was on this search about a year and a half ago, and never finished talking to them.

So please fill us in.  Where is it easily available?

[gripen]

Vermillion,
You can find some of that stuff from the PRO, it takes just couple of minutes to find them if you know what to look for...

BTW they also tested couple N1K1s in the Clark field.

gripen

[wells]

Go here:

http://catalogue.pro.gov.uk/

Search for 'ADM 1/17474'

This is the trials of captured japanese planes against the Seafire III.   The online order form is here:

https://www.pro.gov.uk/recordcopying/orderform/orderform.asp?bhcp=1

It costs 10 pounds for an estimate.  It's cheaper to get paper photocopies than to get scans sent by e-mail.  If you decide to go ahead with the order (after finding out how many pages are involved and how much it will cost), they deduct the 10 pounds from the cost.

[joeblogs]

Probably the best source of data is Rene Francillon's book  Japanese Aircraft of the Pacific War (1989).

According to Francillon, the Ki-84-1a topped out at 392 MPH at 20k ft, a match for the f6-5.

These numbers assume the equipment worked, which it often did not, and does not reflect the substitution of inferior materials in production as the war dragged on.

[gripen]

wells,
Actually you can find even more... a hint: Intelligence reports.

gripen

[-=Silo=-]

Originally posted by Pkun
excuse me.

Do you know?
Ki84 is Max speed in Japan is 624km/h.
But, It's increase ��rototype value.
Its engine is not Ha45-21(2000hp), Ha45-11(1800hp) is.
but, Ha45-21 have limitter(1800hp) on front.
This limitter was not removed at war finish.
But,I heard a few N1K2-J and Ki-84 was removed limitter.
For example,
Ki84-Ib(otu type) recorded 660km/h in Japan.
But,�@this is private value.

This is same on N1K2-J's engine "homare type21(1990hp)", too.
But, I think AH's N1K2-J is reflected it.

I thiink ,TAIU value is removeing limitter Engine value.

TAIU-SWPA's Japanese Plane at Clark field  is J2M3 Raiden(Jack),too.


sorry poor english.


Pkun : Tainannkuu/Overdrive
I want J2M3 Raiden!!!!!!!!!

Pkun, why did the Japanese put limits on the engines?

Interesting that the Ha45-11 was upgraded to a Ha45-21, but then regulated to the -11 horsepower.

Why then did they even use thrust augmentation exhaust to improve performance, so it could be regulated??

Strange.

[Pkun]

hi silo
Its answer is written this book.
"kyokuchi senntouki shidennkai" this is published from "gakkenn"

This is Japanese Book.

Prototype Shidenkai Operation reference book exist in this book.
Its original source was compilated by IJN Aviation headquarters.

Following extract and translat from Japanese
(sorry,my English is poor.May be There is an error in English probably.)

"~~ As a result in experimentation in the sky,some problems clarified.
Those is ,imperfect combustion, Engine over heating, and damage to kelmet.
Spec of NK9H(This is prototype name for Homare type21) is made
same spec of NK9B(This is prototype name for Homare type11).
This named NK9H-B.

~~~Omission~~~

Recently, NK9H-B finally be practical engine, and This could use as NK9H.
But, Some problems clarified.
Those happen in secound gear of super charger.
Those problem is tendency over heating, insufficient of electric system capability.

As a result, NK9H's capability in Altitude is not believed.
Present, NK9H is reserching these problems.
AMC is testing in shiden.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Homare is name in IJN.
Homare is called "Ha45" in IJA.
Homare type 11 is Ha45-11.
Homare type 21 is Ha45-21.

This was written in Jan 1945.

AMC could not complet until war piriod.
I could not find to settle these problem and remove limitter.

I read ,TAIU's Ki84 was changed plug made in USA.
And, I heard ,tendency over heating is settled by up quality of fuel in Japanse test report.

I think ,cause of defferent Japanse value to TAIU value is these problems.

sorry poor english.

Pkun : tainannkuu/overdrive

Originally posted by -=Silo=-



Pkun, why did the Japanese put limits on the engines?

Interesting that the Ha45-11 was upgraded to a Ha45-21, but then regulated to the -11 horsepower.

Why then did they even use thrust augmentation exhaust to improve performance, so it could be regulated??

Strange.

[Pkun]

Sorry ,I forget.
Over Hieating is happened in cylinder.

Its cauce  is proper ratio of mixture air between  fuel to air.

Ha45's proper ratio is short range.

but,IJA and IJN tested N1K2-J or Ki84 having limitter engine or Ha45-11 and gross weight.

Its value is not 2000hp's value.

[Spritle]

A thrust augmenting exhaust wouldn't have too much of an adverse affect on an engines tendency to over heat.  

I would imagine that the overheating was caused by detonation and that the limiter was probably just limiting boost.  Of course this is pure speculation.  Many other factors could have caused it as well, like too small of an oil-cooler, or poorly designed cooling fins and/or air circulation inside the cowl.  But limiting boost would limit the ultimate horsepower and limit the amount of heat.

As to the tests of the Frank at Clark Field.  I doubt very much if the aircraft were really put through their paces there.  More than likely the aircraft were given a quick flight evaluation against PAC Theater US aircraft for comparison.  All of the documentation I have on the Frank lists the tests being performed after the war 1946 (read that as being at Dayton).  

Francillon's book is a really good book, however what were his sources?  Most of his pictures list US Navy Department, USAF or MARU, but as far as his aircraft specs he gives very little information as to their source.  I can't remember if it was this forum or another, but I know that attempts have been made to contact him for more information and all have met dead ends.

Spritle

[gripen]

Spritle,
They certainly did at least rough performance tests at the Clark Field, see for example "The Mustang Story" by Ken Delve. Anyway, accident and failure rate at Clark Field tests appear to have been very high.

Writers tend to protect their sources because many times they have put lot of effort to find them.  And it's same for everyone  if you want to find something, easy stuff is allready found.  In most cases you must go through truck load of papers before you found something you have been looking for.

gripen

[funkedup]

Pretty much all WW2 fighters had a boost limiter of some sort.  Generally WEP was just running the engine beyond the normal boost limits.