Dora vs Tempest

[Soren]

Well then we really can't use it for much. We need to be sure that the a/c were equipped with MW-50 & C3. If the Dora was running at increased boost pressure alone (1,900 PS @ 3,250 RPM) it would allow the Tempest to slowly escape.

With MW-50 & C3 the Dora-9 had a top speed of 615 km/h at SL.

[Jank]

I happened to come across this. Some may find it interesting - Tempest Performance:

Tempest V Performance

[Obsenderunser]

Coffee makers have evolved like everything else in the world of technology. Unfortunately I'm too friggin stupid to even begin to know how to wipe my butt, so i go on websites spamming them with useless gibberish....

[evangilder]

[Boemher]

Originally Posted by Soren

Boemher,

I'm using SonderNotleistung figures (MW-50 & C3), thats 2,100 PS @ 3,250 rpm.

I'm not using the SonderNotleistung Mit A Lader als Bodenmotor figures, in this configuration speeds of over 640 km/h could be reached at SL.

Hi Soren,

With SonderNotleistung Mit A Lader als Bodenmotor the Dora achieves the speed of the Tempest V 11lb Sabre II B. This was the normal Tempest model in service from late 44 onwards.

Some Tempests were modified in 1945 with Rotol propellor blades and Sabre IIC engines at 13lb boost. Closterman famously talks of this plane in his book. He states it had 2800 HP and near enough 3000 HP at overboost and 4000 rpm.

This plane probably saw as much action as the SonderNotleistung Mit A Lader als Bodenmotor Dora if not a little more but imo I dont think it should be used as a yardstick.

Fairer to both the Dora and the Tempest would be to use the main production variants for late 44 and most of 45 which imo give a performance edge to the Tempest V 11lb Sabre IIB at low to medium altitude. The Dora 9 with C3 and Mw 50 was a rare beast was it not? C3 was restricted by 1945 to types which could only run with it ie BMW 801 engined planes. Jumo 213 engined planes like the Dora could use B4, the MW50 was to help improve the Jumo's performance with B4 fuel because obviously B4 was lower octane than C3 fuel so without the use of MW50 B4 fueled variants would be slower than normal C3 variants.

[HoHun]

Hi Boemher,

>This plane probably saw as much action as the SonderNotleistung Mit A Lader als Bodenmotor Dora if not a little more

Do you have any data on the number of thus equipped Doras seeing action? I've love to see that!

Regards,

Henning (HoHun)

[Kurfürst]

Originally Posted by Boemher

The Dora 9 with C3 and Mw 50 was a rare beast was it not? C3 was restricted by 1945 to types which could only run with it ie BMW 801 engined planes.

I have seen much speculation about this in the past, but so far nothing supported the notion that C-3 would be specifically rare, in fact, all the fuel shipments for late-war LW units I`ve seen show a roughly 50-50 B4/C3 ratio, even if most of the planes did not neccesarily required C-3 (which itself appears to be the greater volume of German avgas production, which kinda explains why units, not in dire need of c-3 actually got it instead of B4)

So, I`d like to see some evidence to this C-3 thing you said. I don` buy it, to me this thing born solely out of a desperate partisanship towards certain issues some simply don`t want to accept, and in that process, only the arguements (incl. amongs others, the allaged C3 shortage) change, but the conclusion is always the same.

There`s a very straightforward, two-letter Americanism for that kind of thing, the expression itself probably originating from Texas.

[monsieurmonkey]

One of my Favorite memories from childhood is my Grandfather stradling the nose of a Five propelered Tempest (My Northern Irish Mother's side.) The simple answer is speed. The armaments were similar and both of the planes have been over shadowed by the Spitfire and the 109, even though they were both better planes. They were too expensive for each nation to produce after USA offered such reliable and inexpensive planes for and against.

[Boemher]

As far as I know no squadrons were equipped with the type and it or they only existed in very few numbers. So iirc there was no recorded use of the type or if there was it would be one sortie or something similar.

The C3 fuel issue is not BS as far as Im aware. The reason the MW50 was added to the Dora 9 was to restore performance eroded by downgrading from C3 fuel to B4 fuel. Ofcourse if a Gruppe could get their hands on C3 they would use it but their was definately a fuel issue in Germany and there were certainly limitations on what aircraft could use what. BMW 801 equipped aircraft could ONLY use C3 so obviously they had priority. With Bf 109 squadrons C3 and B4 supplied units existed at the same time but this depended on location and supply. There would be a fair chance that by 1945 you would not encounter a C3 fueled D9 - it was by no means the normal opposition.

This still leaves us with even the best inservice D9 (MW50 + C3) being slower than the standard Tempest (Sabre IIB 11lb) serving with the 2nd TAF.

[Soren]

Boemher,

No Dora in service ever flew with the A Lader als Bodenmotor configuration (2,240 PS).

And no Tempest in service reached 640 km/h at SL either.

The SL speed of the MW-50 equipped Dora's and the Tempest was virtually the same.

[Boemher]

Hi Soren,

There is a performance chart at WW2 Aircraft performance that says a Tempest reached 404 mph at sea level. So just over 640 km/h. I think this may have been a V1 chaser. The 9lb Sabre II A Tempest could reach 377 mph at sea level and 405 mph at 6000ft. The Sabre IIB 11lb variant using 100/130 octane fuel reached 410 mph at 4,500 ft.

How fast at sea level, was the fastest D9 variant that saw service? 613 km/h?

The earliest Tempest V that saw service (April 44) achieved 607 km/h at sea level.

The normal Tempest V - the 11lb version that fought the D9 was faster than this. It had over the earlier Tempest an extra 240 HP at sea level and 230 HP more at 13,000ft and had cleaner lines thanks to the Mk V Hispannos which fitted entirely within the wing structure (estimate increase in speed between 3/5 mph for this improvement alone)

So I still believe the Tempest was usefully faster than the D9 at low altitude.

[Boemher]

Originally Posted by Soren

The SL speed of the MW-50 equipped Dora's and the Tempest was virtually the same.

That should read the SL speed of MW-50 + C3 Doras. I also strongly believe that the few 13lb boost Sabre II C Tempests could readily exceed 400mph at sea level. But I dont think they were active enought to warrant comparison

[Soren]

Boemher,

Yes I know about the chart at Mike Williams site, problem is it's a estimate and doesn't represent the performance of the a/c in service. The top performance of the Tempests in service was ~378 mph (604 km/h) at SL.

The Dora-9's in service with the MW-50 system and C-3 fuel had a top performance of ~615 km/h (384 mph) at SL. With the far more present Oldenburg system the Dora-9's had a performance of ~590 km/h at SL.

[Boemher]

Soren the top speed of a Tempest in April 44 was 607 km/h I agree, but the Tempest in service from Autumn 44 onwards was faster than this. From 625 kmh to 640 kmh.
607 kmh is the SL speed of the Tempests that were facing Fw 190 A8s and Bf 109 G6s not D9s.

This is the difference between a low boost model and a high boost model or in German terms a derated model and a normal model

The Tempest V recieved two major blanket speed increases the 1st was the increase from Sabre IIA 9lb to Sabre IIA 11lb when chasing V1s and the second was Sabre IIA 11lb to Sabre IIB 11lb when operating as part of the 2nd TAF from bases in Europe.