Jackpot of new data!!!

[F4UDOA]

Gents,

I have just received a 30 page report from a contact at the Vought archieves.

It features detailed comparative information on such A/C as the P-47D, P-51B, P-38J, F6F-5, F8F-1, F7F and all F4U varients including drag coefficients!!

I am scanning this data now. Should have it posted soon.

Just as a tease. The P-47D could really benifit from this data. And the Drag numbers in AHT are way off.

Later
F4UDOA

[Rocket]

Any chance I could have you snail mail me a photocopy of this?  

S!
Rocket

[Hooligan]

Coolness!!! You da man!!!!!

Hooligan

[F4UDOA]

Rocket,

I will post it so it can be downloaded. If you want I'll email it to you directly.

Hooligan,

Dude, the speeds at sea level are real interesting. According to the chart the P-47D is as fast at sea level as the F4U-1. It doesn't specify the model but it does list the engine and the fact that it has 2600HP. So that limits the varient possibilties. On the other side the F4U-1 Cd is listed at .020 with the P-47D at .022, F6F-5 at .023. There is so much data I have to finish digesting it all.

Will update soon.

[Daff]

F4U, the P-47D-30 had 2600hp using WEP.
It uses the same engine as the P-47D-25 (P&W-R2800-59), but max MAP was increased.
 As a side note, this was done in the field on all the 56th's 47's from the C-5 and upwards.
 The drag numbers sounds interesting..can't wait for you to get them scanned  

Daff

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CO, 56th Fighter Group
"This is Yardstick. Follow me"

[M.C.202]

Keep digging, this sounds like GOOD stuff.
I would love to have a copy of the full report, e-mail, snail mail, pont express...


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M.C.202
Dino in Reno

[This message has been edited by M.C.202 (edited 02-27-2001).]

[Sundog]

Alright F4!!! Please, if you don't post it all, e-mail it to me. I would really appreciate it. Thanks.

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Sundog
VMF-111 Devildogs
MAG-33

'Criticism is always easier than craftmanship.'

[F4UDOA]

Daff,

The engine listed is the R-2800-63 rated at 2600HP at 64" man. in combination with the Curtiss 12" prop. not the HS. It is very specific about the HP, even including several charts on specific conditions ie climb max speed etc. The chart is dated Oct. 1944.

However is list the max speed for the P-47D as being

14,087LBS
Sea level 354MPH
20,000FT 419MPH
26,500FT (critical alt) 441MPH

With an initial rate of climb of
3,170FPM
7.6 min to 20K

Stall speed 87MPH at 11,949lbs

This is a Vought document with more data on other A/C than I have seen in any one place other than AHT. To bad no foreign A/C listed.

[funked]

Hmm where is that missing MP on the AH D-30?  

[Daff]

Hmm I got the P&W R-2800-63 as being used on the P-47D-11 to -20. (From AHT)..I'll have to look through my other books to confirm this.
(Although since engine changes were very minor from the R-2800-21 and upwards, I dont know how strict they were about using same serial #'s?)
 If it is a D-11/-20), it has probably had the MAP increased post-factory.
Weight indicates it's a D-25 or higher (with aux. main intl fuel tank).
Max speed is a good 20mph better than the D-25 data I have, whereas Sealevel speed matches.

Daff


------------------
CO, 56th Fighter Group
"This is Yardstick. Follow me"

[Widewing]

 

The engine listed is the R-2800-63 rated at 2600HP at 64" man. in combination with the Curtiss 12" prop. not the HS. It is very specific about the HP, even including several charts on specific conditions ie climb max speed etc. The chart is dated Oct. 1944.B]

I believe that they have mis-identified the propeller. Only the early P-47s used the 12'2" Curtiss Electric prop. All D models were fitted with either the 13' or 13'2" Curtiss or Hamilton Standard.

The Curtiss props used the same C642S hub assembly, with the early P-47s using the 714-1C2-12 blades. After the switch to paddle blades, the Curtiss props swung the #836 blade, which measured 13'2".

Now, the engine: Some P-47C models and all P-47D models up through the D-20 were fitted with the -63 engine. However, the power rating, with water injection was 2,300 hp @ 54 in/Hg in WEP. Later version of the -59, which were fitted to the P-47D-27 through the P-47D-40 were rated at 2,600 hp @ 64 in/Hg in WEP. So it's obvious that the aircraft tested by Vought had its original engine replaced with a later varient (although it carried the lower dash number of -59). This was not unusual as the engines were interchangable from the P-47D-5 on. Indeed, this illustrates one of the many reasons that cause performance to vary considerably from published numbers. Hanging
a 2,600 hp engine on a Razorback will produce some pretty impressive speeds given the lower drag associated with the earlier models as compared to the bubble canopy aircraft.

However, it does appear that Vought lists the wrong output for the -63. I suspect the plane they tested was actually fitted with the -59. Either that or they over-rated the power output.

My regards,

Widewing

[eddiek]

Should be interesting to see how this one plays out.
No doubt you guys have access to reference materials that I can only dream of, but can you honestly call a test document from that era wrong?
Just a supposition, but is not most if not all of the "Biblical"(i.e. America's Hundred Thousand) data everyone quotes based on tests conducted back then?
These guys put their hands on, laid eyes on, the planes.  I am sure they knew what engine and prop the birds had.
What gets me the most about topics like this, is there is always someone saying "nope, that is wrong.  I have numbers from (insert info source) that says differently."  Sounds to me like F4UDOA has stumbled onto a treasure of info, and some don't like what they are hearing.
Since the Jug is my plane of choice, any historical info on her is welcome, pro or con.  I have seen accounts of the pilots themselves discounted as unreliable, men who flew these birds in combat and knew what they could and could not do.  "Give us hard numbers, real test data" is always the reply.
Well, here are those numbers.
As a Jug lover, what I would love to see is how many of them received the "in the field" MAP tweak.  Robert Johnson was quoted in another thread on the BBS as saying that his Jug could put out 72" MAP.  If this was a common field mod, and I have little reason to doubt that it was, why not include it in AH, maybe as a perk mod or something of the sort.
Widewing, Daff, if I ticked ya off, I apologize.  This, the Jug, is a sore spot with me.
BTW, what books/documents are you getting your numbers from?  Just curious........

[This message has been edited by eddiek (edited 02-28-2001).]

[Zigrat]

sounds great f4udoa, the p47 d30 definitely seems a bit underpowered to em too.

i dont understand why even have a d25 in the gameee, would have eben better to include a d-5 or a 47-c imo, something with a razorback

[Vermillion]

Eddiek, yes alot of the data these guys are quoting from are original test documents and not commonly available reference books you can pick up at Amazon or Barnes & Noble.

Some of us go to great lengths to get such information and documents.

And in regards to the data from AHT, yes it is based upon original test data from that period. Just look at the reference list at the end of each chapter.

I also don't think anyone is saying that the data that F4UDOA is posting is "wrong", I think everyone is just trying to figure out why it is different from other data that is commonly available.

For one, there is just a normal variability of performance from aircraft to aircraft, even from the same production line, due to quality of finish and other factors. Another is cases similar to what may be happening here, where you basically have a non-standard aircraft (if Widewing is correct). A later model engine in an earlier model airframe, or an engine that has been "hotroded" by boosting the supercharger pressures, are just two examples.

That the thing about test data, you can have two different sets of tests, that show different results. Sometimes significantly. Thats where Pyro eventually has to make a judgement call on what is the "best" set of data.

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Vermillion
**MOL**, Men of Leisure

[Daff]

Oh, I'm not saying that what F4U has is wrong..I'm merely trying to figure out what kind of P-47 it is  .
I often seen test reports just refer to the P-47 as a "P-47D"..and as you know that's kinda vague with 20-odd variations of the D-model  .
 Most of my info is from reference books, with a few pilot-reports, NACA-documents and pilots manuals thrown on top...unfortunatly none of them are "complete". Even "The P-47 Thunderbolt, From Seversky to Republic" has big gabs in it, despite being the "bible" about P-47's.
 I read the Johnson Interview..there's also a WB player who has had contact with a P-47 pilot (Might have been family, cant remember) and said the same and that they used 150 octane gas...but for "sim" purposes, I dont believe in modelling "field mods"...it would simply never end. Modelling them as they were when they rolled out of the factory, is the only reasonable way of doing it.
(Imagine the whining if they modelled a C-5, with waterinjection, 72" MAP, 150 octane gas and paddlebladed prop that did 470mph@30k? )
 As for the prop, the Republic kept on experiementing with various types, even after the paddlebladed Hamilton/Curtiss ones. It could be a typo, but it could also just be yet another variation .
Does it mention where they got the plane from, F4U?.

Daff

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CO, 56th Fighter Group
"This is Yardstick. Follow me"