Here's a consolidation of the information I've found so far.
Komatsu B78 IFV
Built by Komatsu, the JSDF in the late ’70s started a project to design an Infantry Fighting Vehicle that would aid troops in the field while also providing armored fire support. Mitsubishi and Komatsu both built their own prototypes. Komatsu B78 is an IFV prototype not much taller than the Type60 APC, and was expected to mount a stabilized Oerlikon KBA 25 mm Autocannon, a 7.62 coaxial machine gun and a missile launcher mounted on the side of the turret. Type 79 Jyu-MAT seems to be the ATGM candidate. The prototype was built to be compact, giving it a low silhouette. The B78 boasted a top speed of over 72kmh on flat roads.
The prototype used a Cummins VTA903T engine. But it’s probable the production version would have used a Japanese-made engine. Probably the same as the Type 89, the Mitsubishi 6SY31WA Water-cooled 6-cylinder diesel 600 hp at 2,000 rpm.
The B78 completed testing in 1983 and was evaluated by the Japan Ground Self-Defense Force. However, the prototype had insufficient mobility in its turning. Compared to the Type 89, the B78 had a better p/w ratio and a lower silhouette. It made it very small and not very comfortable for the occupants. It also had reliability issues, with engines prone to frequent failures.
Specifications:
Komatsu 105 GSR
A tank destroyer based on the B78 was also proposed to replace the old Type 60 Self-propelled 106 mm Recoilless Gun. Development began in 1981, and by 1984 a single prototype was built. It was equipped with an uninhabited small-size turret with a 105 mm gun mounted in it. Even if it looks comparable to Teledyne AGS and the future Stryker MGS, not much information is available about it. Except that it was planned to be jointly developed by Mitsubishi and Komatsu, it was obviously an unmanned turret with autoloaders, compatible with all 105 mm. The prototype used a 105 mm JSW GSR recoilless gun (license production of the British 105 mm L7 gun) and used on the Type 16 MCV.
Sources:
View: https://www.reddit.com/r/Warthunder/comments/7gpcwc/b78_prototype_ifv/
View: https://www.reddit.com/r/TankPorn/comments/hb1fy6/an_obscure_cold_war_ifv_the_komatsu_b78/
View: https://www.reddit.com/r/Warthunder/comments/x2pkb7/gaijin_please_the_komatsu_b78/
View: https://www.reddit.com/r/TankPorn/comments/14aw92t/komatsu_b78_infantry_fighting_vehicle_remastered/
View: https://twitter.com/NAMELESS_JSDF/status/1596682533277679616
View: https://www.reddit.com/r/Warthunder/comments/x0tug4/gaijin_please_komatsu_105gsr/
View: https://www.reddit.com/r/TankPorn/comments/o69h8q/komatsu_105_gsr_prototype/
View: https://twitter.com/Ninja998998/status/1408278462088060930
https://raigap.livejournal.com/804422.html
Komatsu B78 IFV
Built by Komatsu, the JSDF in the late ’70s started a project to design an Infantry Fighting Vehicle that would aid troops in the field while also providing armored fire support. Mitsubishi and Komatsu both built their own prototypes. Komatsu B78 is an IFV prototype not much taller than the Type60 APC, and was expected to mount a stabilized Oerlikon KBA 25 mm Autocannon, a 7.62 coaxial machine gun and a missile launcher mounted on the side of the turret. Type 79 Jyu-MAT seems to be the ATGM candidate. The prototype was built to be compact, giving it a low silhouette. The B78 boasted a top speed of over 72kmh on flat roads.
The prototype used a Cummins VTA903T engine. But it’s probable the production version would have used a Japanese-made engine. Probably the same as the Type 89, the Mitsubishi 6SY31WA Water-cooled 6-cylinder diesel 600 hp at 2,000 rpm.
The B78 completed testing in 1983 and was evaluated by the Japan Ground Self-Defense Force. However, the prototype had insufficient mobility in its turning. Compared to the Type 89, the B78 had a better p/w ratio and a lower silhouette. It made it very small and not very comfortable for the occupants. It also had reliability issues, with engines prone to frequent failures.
Specifications:
- Length: 6.16 meters
- Width: 3.14 meters
- Height (top of the turret): 2.15 meters
- Height (chassis only): 1,155 meters
- Weight: 20 tons
- Armament:
- 1x Stabilized 25 mm Oerlikon KBA
- 2x ATGM’s (most likely the Type 79 Jyu-MAT)
- 1x 7.62 coaxial machine gun
- Top speed: 67 kph
- Engine: Cummins VTA903T
- Engine power: 600 hp
- Power-to-weight ratio: 30 hp/ton
- Suspension: torsion bar
- Undercarriage: 6 rollers
Komatsu 105 GSR
A tank destroyer based on the B78 was also proposed to replace the old Type 60 Self-propelled 106 mm Recoilless Gun. Development began in 1981, and by 1984 a single prototype was built. It was equipped with an uninhabited small-size turret with a 105 mm gun mounted in it. Even if it looks comparable to Teledyne AGS and the future Stryker MGS, not much information is available about it. Except that it was planned to be jointly developed by Mitsubishi and Komatsu, it was obviously an unmanned turret with autoloaders, compatible with all 105 mm. The prototype used a 105 mm JSW GSR recoilless gun (license production of the British 105 mm L7 gun) and used on the Type 16 MCV.
Sources:
View: https://www.reddit.com/r/Warthunder/comments/7gpcwc/b78_prototype_ifv/
View: https://www.reddit.com/r/TankPorn/comments/hb1fy6/an_obscure_cold_war_ifv_the_komatsu_b78/
View: https://www.reddit.com/r/Warthunder/comments/x2pkb7/gaijin_please_the_komatsu_b78/
View: https://www.reddit.com/r/TankPorn/comments/14aw92t/komatsu_b78_infantry_fighting_vehicle_remastered/
View: https://twitter.com/NAMELESS_JSDF/status/1596682533277679616
View: https://www.reddit.com/r/Warthunder/comments/x0tug4/gaijin_please_komatsu_105gsr/
View: https://www.reddit.com/r/TankPorn/comments/o69h8q/komatsu_105_gsr_prototype/
View: https://twitter.com/Ninja998998/status/1408278462088060930
https://raigap.livejournal.com/804422.html
