Author Topic: To whoever asked me and didn't believe the P-38J is faster than the P-38L... (Read 798 times)

Ack-Ack · « **on:** July 01, 2005, 12:28:16 AM »

P-38J
crew: 1
wingspan: 52' 0"
length: 37' 10"
height 12' 10"
wing area: 328 sq ft
powerplant: 2 x Allison V-1710-89/91 Vee-12 liquid-cooled engines
max speed: 420 mph at 26,500 ft
weight, empty: 12,780 lbs
weight, loaded: 17,500 lbs
weight, max: 21,600 lbs
service ceiling: 44,000 ft
armament: One 20mm cannon /w 150 r. four 0.50 cal mgs /w 500 rpg
# built: 2970

--------------------------------------------------------------------------------
P-38L/M*
crew: 1
wingspan: 52' 0"
length: 37' 10"
height 12' 10"
wing area: 328 sq ft
powerplant: 2 x Allison V-1710-111/113 Vee-12 liquid-cooled engines
max speed: 414 mph at 25,000 ft
weight, empty: 14,100 lbs
weight, max: 22,000 lbs
service ceiling: 44,000 ft
armament: One 20mm cannon /w 150 r. four 0.50 cal mgs /w 500 rpg
# built: 3923

Told you so. And as you can see, it's the lighter weight of the J that gives it the marginal speed over the L, despite the newer and better Allisons the L had. Now does this translate to an advantage for the J? I guess in a level chase, the J would eventually catch up if both planes stay on a level plane. Other than that, I can see no real advantage of 6mph.

ack-ack

Wolf14 · « **Reply #1 on:** July 01, 2005, 01:00:31 AM »

would the 1500ft difference in alt make a 6mph difference in speed as well?

Schutt · « **Reply #2 on:** July 01, 2005, 06:20:24 AM »

In a lvl chase they would both be on the same lvl... the max speed of the J is at higher altitude though.

Also i heard the J had less drag due to the diffrent engine cowlings, is that true?

If so then i would guess most of the speed advantage comes from the reduced drag?

Wilbus · « **Reply #3 on:** July 01, 2005, 07:15:42 AM »

Which one has the highest deck speed?

rod367th · « **Reply #4 on:** July 01, 2005, 07:40:27 AM »

p38 j 200ft no wep 332mph in ah2.......................... .p38l 200ft no wep 333mph ah2.

Both had 50% fuel

Balsy · « **Reply #5 on:** July 01, 2005, 07:55:06 AM »

Weight has nothing to do with maximum speed. If you dont believe me, take any plane up with 100% fuel and then 25% fuel.

Balsy

Keiler · « **Reply #6 on:** July 01, 2005, 08:18:25 AM »

That would be in Aces High 2?... which surprises me.
More weight means more drag due to higher AOA thus lower speed.

Balsy · « **Reply #7 on:** July 01, 2005, 08:28:05 AM »

Im no aeronautical engineer but.. .in level flight/maximum speed isnt the AOA the same?

If I take a 727 up to 20K empty, will it fly faster at level flight than a full one?

jon · « **Reply #8 on:** July 01, 2005, 08:36:43 AM »

i was just at the bong memorial in superior wisconsin(about 15 miles frome his home town of Poplar WI.)and the info there said that the 38L had a top speed of 414 and the 38J i cant remember the exact number but its top speed was around 385

[/IMG]

dtango · « **Reply #9 on:** July 01, 2005, 09:50:45 AM »

Keep in mind AOA / coefficient of lift is not only dependent on weight but also changes with the square of velocity. Increasing velocity means reduced AOA.

For max level speeds the change in AOA and resulting induced drag due to a change in weight are very small. The impact on max level speeds would be imperceptible unless you're comparing speeds stabilized over a long duration.

For example a Beech Bonanza E33A with a max level speed of about 215 mph, the impact due to weight is about 1 mph per 100 lbs of weight.

Tango, XO
412th FS Braunco Mustangs

slimm50 · « **Reply #10 on:** July 01, 2005, 09:52:50 AM »

My only concern is, which one can I live the longest in?

Wilbus · « **Reply #11 on:** July 01, 2005, 10:13:51 AM »

Thanks Rod, could have done the test my self but was too lazy, appriciate it

Slimm, as for your only concern... the J I'd say.

Deck speed is the most important speed for any plane in AH. The J acording to Rod367th's test is only 1 mph slower at the deck compared to the L and it turns quite a bit better then the L.

The J is most likely the one you can live longest in. BUT it performs worse in high speeds and it doesn't have dive flaps.

slimm50 · « **Reply #12 on:** July 01, 2005, 10:38:22 AM »

Quote

Originally posted by Wilbus
...and it doesn't have dive flaps.

Heh, that's ok. I gave up long ago trying to get higher than everyone else. There was always someone higher than me. So I play below 4K agl, usually.

rod367th · « **Reply #13 on:** July 01, 2005, 12:12:05 PM »

25k no wep p38J 400mph 25k p38L no wep 401 mph

what i found out is j climbs faster and can pull out vertical dive from 25 to 4k hit x and st8 and true flying L model crashed same test.

eilif · « **Reply #14 on:** July 01, 2005, 08:29:01 PM »

Quote

i was just at the bong memorial in superior wisconsin(about 15 miles frome his home town of Poplar WI.)and the info there said that the 38L had a top speed of 414 and the 38J i cant remember the exact number but its top speed was around 385 [IMG]

alot of ppl seem to forget that each plane made in a series is different, depending on the mechanic, and how well he tuned it, how well each part was machined, rivet job, time of year, tempurature, ectra.

the japanese planes had a wide area of performance because they were thrown together so fast and ran on such bad fuel.

i bet some day one of the ubber real sims will have a randomizer that will give each model of plane a unique tuning range.