HT crew, some interesting things about Fw190 A-3

[HABICHT]

hi all, with the 190a5 coming lets bring in some new infos. taken from best 190 book!

on 23.06.42 a 190 A-3 (801d1 engine) from JG2
(ups) landed on airfield "pembry" ,wales.
they tested & compared it with lots of planes
spitVb, spitIX,p51-A , p-38f & against typhoon.
FW vs Spit5b: (short terms only)
190 min. 19mph faster at nearly all alts
at 20k the FW was between 19-37mph faster than spitV.
the 190 had a better climbspeed of +450fpm
up to 20k!!!.

190 vs SpitIX (book only tells merlin MK61)
surprisingly the planes were nearly the same
in CLIMB & LvL speed up to 20K!!!
at higher alt the spit was getting better
(we all know).

comparing the FW vs Spit is very interesting.
these stats are, like mentioned above, from
a FW190A-3. it has the same weapons as the A5 and the same engine.

SO, HT, PYRO and others!!!
will we get a plane with the performance the
BRIT's gave us???
IF not, well i'll be very unhappy.

------------------
 
JG2 "Richthofen"

[This message has been edited by HABICHT (edited 05-29-2000).]

[RAM]

BTW the BMW801 engine was faulty and was underrated on power.

Anyway I've seen this before. Lets see the flames rage!!!

Round 1:

GONG!!!

[funked]

Habicht, throw out your book.    

I'm pretty sure HTC has the original AFDU report, which you can find here:
 http://www.geocities.com/spades53.geo/prodocs.htm

Check out the manifold pressures used in the test, and check the manifold pressures you can get in AH.  They are different.  So I don't know if we will get the same performance as this test.

Also note that the A-3 is only 7-8 mph faster than the Spit IX at 2000 feet.  In AH it's more like 25-30 mph!


[This message has been edited by funked (edited 05-29-2000).]

[funked]

I checked the manifold pressures:

In the AFDU test:  
A-3:  1.42 atm
Spit V:  12 psi
Spit IX:  15 psi

Aces High
A-3:  43" Hg  (about 1.43 atm)
Spit V:  16 psi
Spit IX:  18 psi

This is a significant difference in power.  For some reason the AFDU did not operate the Spits at full power.  Or Pyro got the manifold pressures wrong, which I doubt.

Also Fw 190A-3 is a little lighter than Fw 190A-5 which is significantly lighter than Fw 190A-8.

So to do an AH test to compare with the AFDU test, you will need to operate the A-5 at reduced weight (less than maximum fuel), and operate both Spits at the reduced power settings.

Please do this test before you decide whether to be very unhappy or not.    


[This message has been edited by funked (edited 05-29-2000).]

[wells]

Climb power settings were even less than those.  The test reports that sustained climbs were done at maximum continous climb settings.

1.35 for 190
+9 for SpitV (from manual)
+12 for Spit IX (from manual)

Looks like our Spit IX doesn't have the Merlin 61 engine, but rather a 66 or 70 if it's gettin' +18 for combat!  

I suspect the MkV's were limited to +12 due to lower than 100 octane fuel???  It certainly looks like that's the case for the P-38 as well (only 42" for speed run?)  Looks like 87 octane was being used.  The Max Man pressure for a P-38 with 91/96 fuel was 47" and 54" with 100/130 fuel.  Perhaps the engine troubles on the Fw-190 were due to the lower octane as well.  Seems to me the 801D2 with it's higher compression ratio required 96 octane.  Maybe it was detonating at 1.42 ata with 87 octane???

[funked]

Wells, 1.42 ata is beyond the max pressure for the 801C, so yeah I think the D would need better fuel.  I've read other stories of rough running and fouled plugs on other captured 190's that performed better than factory specs(!), so I don't know what to make of that.  I wish AFDU had said what the fuel was...

Notice also that there is a note saying the Spit V was later cleared for operation at 15 psi.  "Cleared for operation" sounds to me like there was not a question of fuel octane, rather some reliability question that was answered favorably.

I don't have a lot of information on Spitfire engines, but our plane performs better than Merlin 61 test data I have seen, so it makes sense if it is a 66 or 70.


[This message has been edited by funked (edited 05-29-2000).]

[HABICHT]

funked, i read the report,
and like i said, there are only little
differences between fw190 and spitIX.

i'd only liked to say, that i want a a5
which is possible to climb with a spitIX
up to 20k. not like our a8 is now!
(couldn't climb with a bomber..lol)
the HUGE speed differences were between
the FW and the SPIT5, and thats ok.

------------------
 
JG2 "Richthofen"

[funked]

Habicht, read the stuff Wells and I are saying about the manifold pressure.  This is CRITICAL to the comparison.  Fw 190 was operating at full power but the Spitfires were not.

[Nashwan]

The Spit IX was an early one. They were later cleared for +18lbs, +25lbs with 150 octane. We have the standard Merlin 61.
I remeber some time ago the debate over the Spit IX cutting under negative G, and this test was refered to. If this plane didn't have the pressure carb, could that be why it was limited to +15lb boost? I'm no engineer so I would know wether the pressure carb would allow higher boost pressure.

[This message has been edited by Nashwan (edited 05-29-2000).]

[funked]

Thank you for clarifying that.

[juzz]

The first of the Mk IX(Merlin 61) were actually inferior in performance to the Mk V(Merlin 45) at about 17-20k.(wells was kinda right.   ) The Air Ministry or someone kicked up a bit of a stink about it at the time.

Part of the reason is the Merlin 45 is at its peak(FTH) around 18-20k, while the Merlin 61 is in a performance "hole" between the MS and FS supercharger speeds. See the speed/alt charts here to see what I mean(Even though the Mk IX is shown as faster).

Erm... do you reckon we will ever see a Fw 190A-2? How many Fw 190A's were produced with the 801C engine?

[This message has been edited by juzz (edited 05-30-2000).]

[wells]

426 A2 were supposedly produced.
509 A3
894 A4
723 A5
1334 A8
674 D9

[jmccaul]

Thers also an intresting pilots comparison between the spit 9 (merlin 66) and 190. I think it's on the last page.

[funked]

Hmm jmccaul thanks for pointing that out.

So he found the climb inferior to the Spit IX with Merlin 66, even though he was at low altitude where the 190 should be at its best.

Also at the end he finds the Merlin 66 Spit fire "much superior at all levels".

I don't think this issue is as clear-cut as many Eric Brown readers would like us to believe.

We know the AFDU speed runs were made with the Spits using considerably less pressure than is available in AH, while the Fw used the "takeoff/emergency" rating.  The climb runs were made at "maximum continuous climbing conditions" which are not stated for the Spits and are stated as 1.35 ata / 2450 rpm for the Fw.

So once we get the A-5, we will be able to make a pretty close comparison for speeds, but climb comparison is not possible unless we know what manifold pressure was used for the Spits.

You following this Habicht?  

[This message has been edited by funked (edited 05-30-2000).]

[Hristo]

 

Originally posted by wells:
426 A2 were supposedly produced.
509 A3
894 A4
723 A5
1334 A8
674 D9

If I fly A-5 instead of A-8 in 1944, would I be gaming the game. I mean, would it be unhistorical ?