Author Topic: Bf109G-6 with MW50 .. what the heck ... (Read 1807 times)

gatt · « **on:** November 16, 2001, 03:15:00 AM »

Take a look at climb times and max speed at altitude (from "Close-Up" series by Thomas H. Hitchcock):

HoHun · « **Reply #1 on:** November 16, 2001, 04:02:00 AM »

Hi Gatt,

thanks for the post!

There seems to be a typo in the "maximum emergency speed at maximum altitude" column for the Bf 109G-6/R2, it probably should read 666 km/h instead of 566 km/h.

Too bad there's no climb chart provided for WEP! From a quick calculation, I'd estimate the Me 109G-6/R2 climb rate with MW50 injection at about 28 m/s at sea level.

Regards,

Henning (HoHun)

HoHun · « **Reply #2 on:** November 16, 2001, 06:11:00 AM »

Hi again,

>From a quick calculation, I'd estimate the Me 109G-6/R2 climb rate with MW50 injection at about 28 m/s at sea level.

Talk about typos! My estimate is 25 m/s.

Regards,

Henning (HoHun)

gripen · « **Reply #3 on:** November 16, 2001, 06:16:00 AM »

Well, Hitchcock's data is quite questionable. Just look those speed and climb curves, the DB605 had variable speed supercharger so why there are those steps in the curve?

gripen

mw · « **Reply #4 on:** November 16, 2001, 06:49:00 AM »

I noticed that too gripen, looks more like Spitfire curves.

Porta · « **Reply #5 on:** November 16, 2001, 07:41:00 AM »

Hitchcock's data comes from official Luftwaffe charts, as mentioned on the top of the image.

Other german charts (captured documents now stored at IWM) show similar "steps" in speed.

[ 11-16-2001: Message edited by: phantasma ]

Vector · « **Reply #6 on:** November 16, 2001, 10:45:00 AM »

Quote

Originally posted by gatt:
Take a look at climb times and max speed at altitude

I just did some rough climb tests:
Climb time to 20k 25% fuel
109F-4: 5'53 / WEP: 5'05 (average ft/min: 3399/3934)
109G-2: 5'41 / WEP: 5'01 (average ft/min: 3519/3987)
109G-6: 5'53 / WEP: 5'11 (avegare ft/min: 3399/3859)
109G-10: 5'36 / WEP: 4'27 (average ft/min: 3571/4494)

seems to be similar to that data, with more fuel, it'd be over 6 mins.
Note: considering my ablility to do math, above numbers are prolly BS

vector

[ 11-16-2001: Message edited by: vector ]

gripen · « **Reply #7 on:** November 16, 2001, 12:22:00 PM »

phantasma,
well, It does not matter where from that data is. There is no such steps if the supercharger is variable speed system. That data is clearly wrong.

gripen

funkedup · « **Reply #8 on:** November 16, 2001, 12:38:00 PM »

Yep those are curves for an engine with a 2-speed supercharger --> Not a DB 605.

funkedup · « **Reply #9 on:** November 16, 2001, 12:42:00 PM »

NM

[ 11-16-2001: Message edited by: funkedup ]

Regurge · « **Reply #10 on:** November 16, 2001, 12:45:00 PM »

Looks like that climb/speed chart is from a FW190A.

wells · « **Reply #11 on:** November 16, 2001, 01:41:00 PM »

The gear ratio for the supercharger in the DB605 was 10.07:1. How is that variable speed?

funkedup · « **Reply #12 on:** November 16, 2001, 02:08:00 PM »

Wells, they used a clutch to control blower speed. Clutch slip was controlled barometrically. Below rated altitude the clutch slipped, reducing the blower speed. At rated altitude and above the clutch was fully engaged and there was no slip.

If they quote a gear ratio for this mechanism then it is based on tooth counts and would only apply at or above rated altitude.

[ 11-16-2001: Message edited by: funkedup ]

butch2k · « **Reply #13 on:** November 16, 2001, 02:15:00 PM »

This data is definitely wrong, it fits better a 190 or a Spit than a 109. The data i have on various 109 versions is definitely diferent from this one.
here is one for the K4, notice the difference, other 109 speed graphs are similar in shape.

and one for the G.

[ 11-16-2001: Message edited by: butch2k ]

funkedup · « **Reply #14 on:** November 16, 2001, 02:28:00 PM »

Boy those Rooskies sure captured a crappy Fw 190A-5!

Hey Waffles you guys want HTC to use this "authoritative" Rooskie data instead of the "biased" USAAF data they have now?

[ 11-16-2001: Message edited by: funkedup ]