Author Topic: P40E vs Bf109E4 (Read 410 times)

funkedup · « **Reply #15 on:** October 29, 2002, 06:01:36 PM »

Do you know the boost and rpm and durations for those outputs?

GRUNHERZ · « **Reply #16 on:** October 29, 2002, 06:27:13 PM »

The 1175hp is take-off power. Another figure I have is 1000hp at 12,140ft. This is the motor in Bf109E3 and E4.

I think HoHun could have more detailed info than that for some of the earlier DB601 variants as used in the E1 but not the exact type as used in the Bf109E4.

GRUNHERZ · « **Reply #17 on:** October 29, 2002, 06:45:15 PM »

I have also been looking around for info on the Allison V1710-39 as used on the P40E and all find is the 1150hp.

The ~1300hp 1710 variants only show up on the P40K but this was the V1710-73. The P39D used a V1710-63 producing some 1300hp. But again thats not a -39.

So it seems the 1300hp figure would be innacurate and too high for a P40E, if thats what these figures show in your calculations.

I really wonder whats up with these climb numbers....

AKDejaVu · « **Reply #18 on:** October 29, 2002, 06:49:30 PM »

So the charts show the P-40E outclimbing the 109E up to 9k and only with WEP. Is this that hard to believe?

AKDejaVu

GRUNHERZ · « **Reply #19 on:** October 29, 2002, 07:13:25 PM »

Well apparently yes, the known AH weight and well known accepted hp figures for the specific aircraft dont really match the AH performance.

funkedup · « **Reply #20 on:** October 29, 2002, 07:22:23 PM »

Keep in mind most of the published ratings for the Allisons are not WEP figures. As HoHun was alluding to, they could be overboosted. That's where the 1325 hp on the P-39D comes from, even though the nominal figure of 1150 hp is usually given for that type. The engine in the P-40E was almost identical, differing mainly in the prop drive arrangement, so it seems that it would be capable of overboost as well.

Without seeing some kind of documentation of the testing it's all speculation though.

GScholz · « **Reply #21 on:** October 30, 2002, 01:06:19 AM »

There should be plenty of info on both planes out there ... somewhere. If HT has modeled a 109E4 with lower hp than the most prolific production model, and a P40E with more than average hp ... why?

Blue Mako · « **Reply #22 on:** October 31, 2002, 12:06:08 AM »

Apples and oranges.

HoHun · « **Reply #23 on:** October 31, 2002, 01:13:42 PM »

Hi Blue Mako,

>Apples and oranges.

Aerodynamics are a science, not an art, so there's certainly something to be gained from a thorough comparison.

Since it obviously is a difficult topic, any constructive comments would be highly welcome! :-)

Regards,

Henning (HoHun)