P-38J with V-1710-89 engines, rated at 1575 hp and 66 in. Hg at 10,000 feet.
Altitude - RoC - Time - TAS Mph
0 - 4000 - 0 - 160.0
5000 - 3960 - 1.25 - 170.0
10000 - 3820 - 2.54 - 183.5
15000 - 3550 - 3.89 - 198.0
20000 - 3190 - 5.37 - 214.0
23400 - 2900 - 6.49 - 224.0**
25000 - 2665 - 7.06 - 229.0
30000 - 1830 - 9.32 - 243.5
35000 - 980 - 12.99 - 259.0
** = Full throttle height.
This isn't DIRECTLY applicable to a P-38L, but it's close.
P-38Ls after the very first production examples had the V-1710-113 rated at 1600 hp WEP, or just an extra 25 horse power per engine than the P-38J. However, they could hold this power for longer periods and at higher altitudes than the V-1710-89s on the J model.
P-38Ls were heavier and slightly draggier than Js because of extra equipment and the fitting of the dive brakes. Top speed was down about 6 mph, climb was slower down low, but better beyond 22,000 feet.
Later in the war (mid to late 1944) the USAAF increased the engine rating up to 66" Hg with War Emergency Power, with British 150 octane in the ETO or 115/145 in the Pacific. Horsepower jumped by about 125 hp per engine, to around 1725 hp.
Speed and climb were increased by about 5-10% over the P-38J. According to Lockheed test data at 66" Hg, top speed lept up to around 441 mph and climb was better than 4,400 fpm initially. 20,000 feet could be reached in about 5 and a quarter minutes.
Getting good P-47N data is harder than nailing jelly to a wall, so I don't have anything solid.
What I do have is some P-47D performance charts with the R-2800-95(W) and A-17 type turbosupercharger, rated at 70" Hg and 2,535 horsepower, which was introduced from late 1944. P-47 crews were notorious for pushing the big radials harder than the were supposed to. I have one report of a crew chief who pulled the stops on the turbosupercharger, allowing his pilot to push the R-2800 up to 90-100" Hg for about 30 seconds. This was an early D razorback, without water injection as well
At 70" Hg, a P-47D-27 with a paddle bladed prop, would climb at 3,200 fpm off the deck and maintain that RoC all the way up to about 16,000 feet. After this, climb began to fall off.
20,000 feet: 3,000 fpm
24,000 feet: 2,550 fpm
28,000 feet: 1,950 fpm
32,000 feet: 1,400 fpm
Top speed was 444 mph at 23,200 feet. Climb was about 5,00 fpm better than at 56" manifold, and speed was about 19 mph better at full throttle heights.
The Jug was never one of the great climbers of the war . In fact, at war standard 56" manifold pressure and 2,300 hp you'd be hard pressed to find a comprable plane that was any slower in the vertical until that bloody great supercharger made itself felt around 28,000 feet.
The P-47N had a R-2800-73 or -77, both with water injection, and both able to push out about 2,800-2,900 horses. The wing was redesigned and enlarged. The sape was refined slightly and the tips squared off, which increased agility and manouverability. Roll and turn performance were superior to the P-47D and M. It was quite a deal heavier than wither od the D or M though, with new wing, increased fuel, more equipment and strengthned undercarriage all adding up to i ncrease take off weight to over 20,000 lbs.
Best climb for the P-47N is usually given as 2,700 fpm. However, given the increase in power and wing area, as well as performance, of the P-47N, this is probably for 'normal' power of 2,100 hp, not War Emergency Power of 2,800 hp or more. More than likely, performance would of been around or slightly better than that of a P-47D at 75" manfold pressure and 2,535 hp.