Covered previously by others before. However I'll repeat what info I have.
It's not that the finns reduced the weight, it's the US added a bunch of weight instead. According to Dean's AHT, empty weight of the B239 was only 3744 lbs. By contrast the F2A-3 empty weight was 4765 lbs. Where did all that come from? +280 lbs on the airframe, +547 lbs for a new version of the Wright Cyclone 1820 engine, +215 lbs for fixed equipment. The wing weight went up 172 lbs with no change in area. That's just empty weight.
Add the additional fuel and ammo etc etc. and voila you get 5276 lbs vs. 6906 lbs. Looking at the math, that's actually 23% lighter than the F2A-3.
Nice figures.
The finns removed the tailhook and other carrier type equipment but didn't they run 4x50 caliber guns while the original f2A1 was armed with 1x30 and 1x50 guns?
This thread is way off track from it's original intent which is to discuss the I15/I153 biplane being in game.
It's numbers exceed the B239 and many other planes in game at this time.
I only mentioned the brewster because I feel it's flight model most closely resembles how the I15/I153 would fly.....but with a bit of speed removed.
Karnak.......from another thread......
This.
Giving the Allies the B-239 in Pac scenarios isn't very fair to the Japanese as it gives the Allies a fighter that can turn with the A6M when there shouldn't be an Allied fighter there that can turn with the A6M.
They delivered 3437 of these planes.
The I153 were armed with 4x7.62 shkas or 2x12.7 bs.
The I153BS had 4x12.7 and another model had 2x20mm shvak.
They also flew with 6xRS82 rockets.
26 were delivered with pressurized cockpits and turbocharged engines.