Conslaw
Senior Airman
The Japanese Navy's J2M "Jack" fighter and the Japanese Army's Ki-44 "Tojo" fighter were similar in concept and similar in overall performance. Was one better than the other? Why?
Jack vs. Tojo - Which was better? Why?
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Greg Boeser
1st Sergeant
I'm going with the Jack.
Better armed, better climb, better top speed, better ceiling. Just better. And it was a newer design. Ki-44s were being replaced by Ki-84s about the same time the Jack was coming online.
Better armed, better climb, better top speed, better ceiling. Just better. And it was a newer design. Ki-44s were being replaced by Ki-84s about the same time the Jack was coming online.
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Conslaw
Senior Airman
I'm going with the Tojo. It was ready for service a year earlier. They made twice as many of them. The top speeds were similar. They both had a good climb rate, though Jack was better. The Tojo was starting to be phased out in latter 1944 because the Ki-84 Frank was a supurb aircraft that was producable and could perform multipl roles. The navy's (post-zero) general purpose fighters, the A7M and the N1K1, were either not ready for production at all (A7M) or defied mass production (N1K - peak production 106 units/month in Sept. 1944). (Ok, in part I picked the Tojo just to be contrary. I admit it.)
Early Tojo, powered by Ha-41, was not as fast as the later Tojos powered by Ha-109 engines. Once Jack arrived, it looked as a better fighter to me. BTW - Tojo was produced in small monthly quantities, monthly average being less than 50 examples.
Shortround6
Major General
Hmmmm , 2 years newer, engine over 20% more powerful, Looks like the Jack has some definite advantages.
GregP
Major
I think the J2M was the only IJN fighter capable of reliably intercepting the B-29. But they didn't make many, around 670 or so. Also, the quality declined as raw materials became scarce. In good trim, the J2M was formidable.
alejandro_
Airman 1st Class
- 281
- Jul 4, 2005
On paper the Jack was superior, but Tojo was far more reliable. 302 Kokutai reported that no more than 30% of Jacks were usually available. Jack had very serious production issues.
GregP
Major
Mostly engine and landing gear issues, more engine than LG. Haven't heard of any propeller issues.
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Conslaw
Senior Airman
Both the Jack and the Tojo were interceptors. Having a good radio is important to an interceptor. Of course, the Zero is known for having a nearly useless voice radio. Were the radios in the Jack and the Tojo better?
By most book listings, the Ki 44 and J2M were pretty comparable in speed, but the TAIC tested a J2M2 Jack 11 at 407 MPH maximum speed and a J2M3 Jack 21 at 417 MPH which makes the J2M a much faster aeroplane. My understanding is that the typical 370 MPH maximum speed for J2M is for "Overload Fighter" which meant it was carrying a drop tank. The pilot reports also gave the J2M pretty high marks for maneuverability and general handling. I don't have corresponding information on Ki 44 but don't think it was as good.
My vote is for Raiden.
- Ivan.
My vote is for Raiden.
- Ivan.
I would say that the J2M is the better choice as, from what I've found on WW2 Aircraft Performance it has the P-51 beat in climb all the way up to 25000 feet (escort configuration, pylons on wings, tanks punched off), and could get up to around 407-408 mph, with other sources listing around 417 (that said, the P-51B using 75" of MAP to 17900', followed by switching to 67" above that point would keep the P-51 on top from sea level to around 3000-4400; then somewhere between 15000-20000' and up)
They planned to put a turbocharger in the J2M4 from what I read, and if so, it would have been a royal bastard to face off against.
They planned to put a turbocharger in the J2M4 from what I read, and if so, it would have been a royal bastard to face off against.
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Hello Zipper730,
The fuel issue with J2M was the same one that affected other high performance Japanese engines.
Their best fuel standard that was commonly available was either 91 octane for the Army or 92 octane for the Navy.
To compensate for this, most of the late war Japanese fighters carried a LOT of Water-Methanol as an anti-detonant and would use it at settings barely above cruise.
The J2M3 as an example which could carry around 570 liters of internal fuel would also be carrying 120 liters of Water-Methanol.
This was when things were working as intended. As the war progressed and their shipments of oil were interrupted, the fuel quality got worse.
Some of the older engines such as on Ki 43-II and most A6M didn't need ADI to make their maximum power but they also were using lower manifold pressures.
- Ivan.
The fuel issue with J2M was the same one that affected other high performance Japanese engines.
Their best fuel standard that was commonly available was either 91 octane for the Army or 92 octane for the Navy.
To compensate for this, most of the late war Japanese fighters carried a LOT of Water-Methanol as an anti-detonant and would use it at settings barely above cruise.
The J2M3 as an example which could carry around 570 liters of internal fuel would also be carrying 120 liters of Water-Methanol.
This was when things were working as intended. As the war progressed and their shipments of oil were interrupted, the fuel quality got worse.
Some of the older engines such as on Ki 43-II and most A6M didn't need ADI to make their maximum power but they also were using lower manifold pressures.
- Ivan.
31.5 gallons of water methanol. How much did we carry in the US?
Hello Zipper730,
The P-47D-3 through P-47D-25 carried 15 Gallons
After the P-47D-25, this was increased to 30 Gallons.
For internal fuel, before the D-25, total was 305 Gallons.
D-25 and later had 370 Gallons.
- Ivan.
Shortround6
Major General
The F4U and F6F carried closer to 10 gals.
CORSNING
Tech Sergeant
Unfair comparison!
I am agreeing with Wes on this one. The Demon Vanquisher (Ki.44-II) was
first delivered to the JAAF in Nov./Dec. 1942. The god of thunder/lightning
(J2M2) was not delivered to the JNAF until Dec. 1943. During wartime, that
is a like Wes said, a half-generation apart.
Like comparing an Emil to a Spit 14.
Not quit, maybe a Bf 109F-4.
Half a generation apart.
How about a KI84?
Agreed, Ki 84-1a (late model) vs. J2M3 m21 would be way closer in performance.
The only complete performance figures I have been able to come up with for
Japanese fighters is the TAIC reports. On any comparisons that I post, these are
the figures I use. However it must be kept in mind that the TAIC reports are
based on using 92 octane fuel and a well tuned aircraft engine. By 1944 both
were in extremely limited supply for Japan.
A quote from "Aircraft of the Aces No. 129".
" The performance of the Homare engine continued to be lower than expected. Fuel
quality was down to 85 octane because it was mixed with an oil extract from pine tree
roots - this proved to be very volatile. Pilots in the front line still claimed that the
Shiden-Kai's performance was good up to 30,000 ft."
Jeff
Hello Corsning,
While it is true that the Ki 44 Shoki came out earlier, it and J2M Raiden were both were designed for the same role (Interceptor) and both were in service for their respective air services at the same time.
While the Ki 84 was a more contemporary design to J2M, it was more of a general purpose fighter than an interceptor.
The naval equivalent would have been the N1K2-J Shiden-KAI.
As GregP pointed out, there were some problems with the engine installation in the J2M, but perhaps they were not what one might expect.
The engine was the Mitsubishi Kasei. It was a "Bomber Engine".
It was not the more troublesome Nakajima Homare.
The Mitsubishi Kasei was a pretty well proven and reliable engine design unlike the Homare.
The Homare was a small diameter engine (nearly the same as Nakajima Sakae) but with about twice the power if it worked right.
The Kasei was a very large diameter engine with a bit less power and typical installations were on bigger aircraft such as the Kawanishi H8K Emily where the streamlining wasn't so important. Power output and RPM were also much lower.
The big issue was that in order to get a nice pointy nose on the J2M, the Kasei needed an extension shaft and a cooling fan and that setup resulted in a few problems initially. There were other changes with fuel injection and such to raise the output of the engine but I am not sure if those resulted in any significant problems.
In general, allied reports praised the flying qualities and construction quality of the J2M. I don't have equivalent information on Ki 44.
- Ivan.
While it is true that the Ki 44 Shoki came out earlier, it and J2M Raiden were both were designed for the same role (Interceptor) and both were in service for their respective air services at the same time.
While the Ki 84 was a more contemporary design to J2M, it was more of a general purpose fighter than an interceptor.
The naval equivalent would have been the N1K2-J Shiden-KAI.
As GregP pointed out, there were some problems with the engine installation in the J2M, but perhaps they were not what one might expect.
The engine was the Mitsubishi Kasei. It was a "Bomber Engine".
It was not the more troublesome Nakajima Homare.
The Mitsubishi Kasei was a pretty well proven and reliable engine design unlike the Homare.
The Homare was a small diameter engine (nearly the same as Nakajima Sakae) but with about twice the power if it worked right.
The Kasei was a very large diameter engine with a bit less power and typical installations were on bigger aircraft such as the Kawanishi H8K Emily where the streamlining wasn't so important. Power output and RPM were also much lower.
The big issue was that in order to get a nice pointy nose on the J2M, the Kasei needed an extension shaft and a cooling fan and that setup resulted in a few problems initially. There were other changes with fuel injection and such to raise the output of the engine but I am not sure if those resulted in any significant problems.
In general, allied reports praised the flying qualities and construction quality of the J2M. I don't have equivalent information on Ki 44.
- Ivan.
CORSNING
Tech Sergeant
Hi Ivan, good to hear from you sir.
Pick your poison Zipper and I will see what information I have.
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