B17A, B18A, J22A, J22B, J21(All prop variants), J21R, A21RB: Need Engine Power Adjustments (+1.4% to +5.6%)

Machinery of War Discussion Aircraft
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Several Swedish aircraft currently appear to be modeled with lower maximum engine output than specified in Swedish documentation and factory blueprints. The differences are generally small, but they affect historical accuracy across multiple aircraft rather than being isolated cases.

This post has four parts:
1. Propeller Driven Aircraft:
2. Jet Driven Aircraft:
3. Sources, Overview Blueprints + Litterature:
4. Bug Reports:

1. Propeller Driven Aircraft:

Aircraft Current Historical Difference
B17A 1x (STWC3) 1,050 hp 1,065 hp +15 hp (+1.4%)
B18A 2x (STWC3) 1,050 hp 1,065 hp +30 hp total (+1.43%)
J22A 1x (STWC3) 1,050 hp 1,065 hp +15 hp (+1.4%)
J22B 1x (STWC3) 1,050 hp 1,065 hp +15 hp (+1.4%)
J21A-2 1x (DB 605B) 1,450 hp 1,475 hp +25 hp (+1.7%)

The B18B, T18B and T18B(57) all have 1,460 hp for the “DB 605B”

This would result in +1.03% total engine power (2920 → 2950 hp)

Top speed: 570 km/h → 571–572 km/h
Climb: 11.5 m/s → 11.6 m/s
Takeoff run: 400 m → 396–397 m
Service ceiling: 10,000 m → 10,050–10,100 m
Turn time: 27 s → 26.9–26.8 s

The J21A-2 (And likely the J21A-1, A21A-3, since they all used the DB 605B aswell) would gain +1.7% of total thrust. Not alot just a marginal boost.

2. Jet Driven Aircraft:

Aircraft Current Historical Difference
J21R 1x (RM1 / DH Goblin 2) 1,290 kp 1,360 kp +70 kp (+5.4% Added kgf)
A21RB 1x (RM1A / DH Goblin 3) 1,420 kp 1,500 kp +80 kp (+5.6% Added kgf)

The J21R with +5.4% Added kgf and A21RB with +5.6% Added kgf. They are the next most viable changes that can be made.

J21R: Fix Results
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+5.4% kgf
Top speed: 799 km/h → 804–812 km/h
Climb: 21.0 m/s → 22.0–22.3 m/s

A21RB: Fix Results
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+5.6% kgf
Top speed: 850 km/h → 855–865 km/h
Climb: 24.5 m/s → 25.8–26.2 m/s

Sources, Overview Blueprints + Litterature:

“STWC3” is a Swedish-Designed improvement of the “Pratt & Whitney, 14cyl. Twin-Wasp” that was used on the (B17A, B18A, J22A, J22B) that put out 1065 hp

"Det bevingade verket" - "Väsentliga områden inom flygsystem" - page. 235

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SAAB J 21A-2

J21A-2 Ritning
J21A-2 Ritning1440×1047 135 KB

SAAB J 21A-2 (1947)

SAAB J 21R + J 21RB

J21RB Ritning
J21RB Ritning1440×1033 99.9 KB

SAAB J 21R: J 21R + J21RB

4. Bug Reports:

SFA STWC-3 Too low Horsepower (Rejected)

Now i made a Bug report for the STWC3 already but it was shut down due to being within the acceptable error margin.

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So i wont try to argue with that further seeing as it was a dev decision. Wont get anywhere with that.

J 21A-2 + J21RB Incorrect Power Output: (On the way)

J 21R Incorrect Engine Output (Open)
J21RB Incorrect Engine Output (Open)

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10 Likes
2

I have now made bug reports for the:

J 21R Incorrect Engine Output (Open)
J21RB Incorrect Engine Output (Open)

Kindly go and support em^^

3

They think i used AI and shut it down :(

Bruh i tried to make it better structured and it got tagged AI

1 Like
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Generally marginal but would be nice to fix yeah but an overall horsepower graph would be much better as atm its flat 1050 for quite a while and would get you somewhere

It both reaches and exceeds that amount of horsepower, you’d need to clarify the conditions it meets that amount

Well within the rated channel loss percentages which can be as high as 10% of thrust lost and again what conditions

What is meant to be the difference with these? You have listed the Jet powered J21 twice in two different reports on the same thing lmao

5

its not AI generated lol but secondary sources are usually ignored. Channel losses are also a gaijin way to make up thrust values a lot of the time.
image

1 Like
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This very much is generated by AI

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image1165×669 93.3 KB

8

You can’t handle the fact that someone actually likes to put time and work into something they love.

1 Like
9

This is litterarly how i wrote it… The bug report site just didnt make it look like i wanted…



* Issue:
RM1A (DH Goblin 3) engine thrust is too low compared to real-life performance, resulting in slightly reduced speed and climb.

* Current in-game values:
Engine: RM1A (DH Goblin 3) — 1,420 kgf
Max speed (2,000 m): 850 km/h
Climb rate: 24.5 m/s
Turn time: 24 s

* Correct real-life value:
RM1A (DH Goblin 3) should produce ~1,500 kgf

* Expected adjustment (+~5.6% thrust):
Max speed: 850 km/h → ~854–856 km/h
Climb rate: 24.5 m/s → ~25.8–26.0 m/s
Takeoff run: 850 m → ~800–810 m
Service ceiling: slight increase → ~12,250–12,350 m
Sustained performance: improved energy retention in climbs and turns

* Source:
    Two Blueprints, SAAB J 21R. J21RA + J21RB
    From
    "Flygplansritningar. 3 : Svenska Flygvapnets Bomb-, Attack- och Torpedflygpl:"
    ISBN: 9185496251
    Author "Björn Karlström" (1921-2006) (Technical Illustrator / Designer for SAAB)

  • Issue:
    RM1A (DH Goblin 3) engine thrust is too low compared to real-life performance, resulting in slightly reduced speed and climb.

  • Current in-game values:
    Engine: RM1A (DH Goblin 3) — 1,420 kgf
    Max speed (2,000 m): 850 km/h
    Climb rate: 24.5 m/s
    Turn time: 24 s

  • Correct real-life value:
    RM1A (DH Goblin 3) should produce ~1,500 kgf

  • Expected adjustment (+~5.6% thrust):
    Max speed: 850 km/h → ~854–856 km/h
    Climb rate: 24.5 m/s → ~25.8–26.0 m/s
    Takeoff run: 850 m → ~800–810 m
    Service ceiling: slight increase → ~12,250–12,350 m
    Sustained performance: improved energy retention in climbs and turns

  • Source:
    Two Blueprints, SAAB J 21R. J21RA + J21RB
    From
    “Flygplansritningar. 3 : Svenska Flygvapnets Bomb-, Attack- och Torpedflygpl:”
    ISBN: 9185496251
    Author “Björn Karlström” (1921-2006) (Technical Illustrator / Designer for SAAB)

2 Likes
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that is the same format as myself and many others do my reports. not some clanker trash

We write it like that to make it clear enough for a four year old to understand, because otherwise the CBR mods wont always understand it and then notabug us

3 Likes