Recent content by qaz

I have been looking into the strangeness around the Sakae 31 and Ha-115II recently. Based on my research I believe that: Sakae 31 and Ha-115II had the same settings as Sakae 21 and Ha-115. Their outputs at rated power were comparable to the previous engines. The main purpose of WM injection in...

I definitely do not mean to say my vague guess there should be considered reliable. Assessing the real top speed of planes with Ha-45/Homare is nightmarish because there were so many varying factors and very few actual test records. Mainly I just want to caution against the use of high Allied...

It's a common myth that the TAIC performance numbers are derived from US tests with high octane fuel. In most cases, they're just calculated estimates using data that was often dubious. The ones that are derived from actual test data are much tamer. Reasonably, they would rather overestimate...

Very high speed values for Japanese planes are usually pulled from the TAIC calculations of wartime, and those shouldn't be taken at face value. Usually these planes never actually demonstrated such performance. However, in terms of Homare/Ha-45, Japanese speed values are often in a de-rated...

Hi, here's the performance numbers I could quickly find from the documents I can verify. Document 1: 「キ八十四」操縦法 (1/1944) Ki-84 Operation Manual Army Document, Ha-45 (Ha-45-21) Takeoff: 1850hp @ 3000rpm, +400mm Nominal 1st Speed: 1860hp @ 2900rpm, +250mm 2300m Nominal 2nd Speed: 1500hp @...

Hello, sorry for my lack of activity. A little busy and I forgot about the discussion for a while. I finally left a comment on the Flight Model Review video now, in case the author wants to comment on this thread. I'll post the values I have for the Ha-45-21 by the end of today, surely :V. I'm...

It is indeed a very great video. I was surprised to see that such a video like this already exists, and the thorough overview of all the relevant US documents. I don't know if the video's creator has an account here, but I will leave a comment. All fighters used constantly variable pitch at...

@AerialTorpedoDude69 , Because TAIC was able to dimensionally measure the airframe by no means determines that they obtained the correct drag. And even Japanese performance calculations with wind tunnel drag data, correct power numbers, prop efficiency and so on were often at disparity with...

Hi everyone, I'm trying to gather varying Japanese performance data on the Ha-45 so we can get a better idea of its output in different conditions. I'm not sure I can quite keep up with the discussion but I already outlined my position on it well enough probably. In the mean time I just want to...

The full-pressure alt of the Ha-45 changed over time as the engine was developed. It seems that the final number of actual fully-rated engines may have been 6,100m full pressure for mil power, rather than 6,500-6600m range, but it's on sparse data I would not consider conclusive. Basically...

Hi, I'm aware that TAIC had flying Ki-84s during the war. However, this calculation was done by March 1945 as written in the TAIC Manual. It's quite doubtful that any comprehensive max performance test was performed on a captured Ki-84 by this time, and the TAIC manual makes no note that it is...

Certainly, based on this material I agree with the convincing theory written on warbirdperformance's blog: http://warbirdperformance.livedoor.blog/archives/8606170.html That the compression ratio of mass produced/service Ha-45-21 was reduced to 7.17 by diverting the pistons of the prior...

Adding the materials in question: TAIC Manual No.1 https://dl.ndl.go.jp/pid/4009755 T-2 Report on Frank-1: http://www.wwiiaircraftperformance.org/japan/T-2_Report_on_Frank_I_Ki-84.pdf 'Ki-84 Middletown Test'...

I certainly know that Greg is more knowledgeable of the technical aspects than I am, but I just disagree with the use of the 687 km/h number as an accurate reference for a 'best case' Ki-84 for these reasons. The 1946 'test data' that gave 687 km/h is an exact reprint of the TAIC early 1945...

The Type 4 Fighter was mass produced with the Ha-45, but the engine was restricted at the beginning of service to perform almost the same as Ha-45 Special. All service planes with that engine model were also subjected to this. The RPM and CR were both reduced. (IJA Ha-45 Special = IJN Homare...