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Witch_56_SqnRAF
02-19-2006, 03:42 AM
Well... Hmmmm.... http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

As a follower of 56 Squadrons history I'm pleased we have the Tempest, However...

Whilst learning this new plane I found it seemed a bit slow, I decided to do some more testing.

I flew several sorties with fuel loads from full to 25% fuel and default and no ammunition loaded. With these different loadouts the results were surprisingly similar.
I also used maximum power (9Lb's of boost) and varied the Prop RPM, which just slowed the plane down. I though perhaps the big Sabre engine could push the plane along faster with a co****r pitch, but no http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

I used references from a few places that had the historical data on the Tempests performance, most of these are in KIAS, MPH, TAS so I have simplified this below.

The speed for the Tempest @
Sea Level should be 326KIAS, I only managed to sustain 310KIAS

6,000' should be 367KIAS, I only managed 310KIAS

It appears that something's stopping the Tempest from sustaining any speed higher than 310KIAS.

?

As for the Radiator, it seems quite realistic that the engine heats up quickly.

As for the guns, these are the short barrelled Hispano Mk V's, much better weight of fire than the earlier Hispano but slightly less accurate as the barrell was around 10 inches (25cm) shorter, and they fitted more rounds in for each gun.
Has Il2 modelled these new guns ?

An excellent Tempest web site with comparisons with the Bf109K and Fw190D, pilots combat reports and much more http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://www.spitfireperformance.com/tempest/temptest.html

Once again, thanx for the Tempest <S>

Witch

Chuck_Older
02-19-2006, 06:02 AM
What map were you using? It matters. I haven't checked kts, I use mph or kph depending on if I'm Axis or Allies, and knots messes with my head

http://forums.ubi.com/images/smilies/10.gif prop pitch is weird in the sim. For allied aircraft it seems to be more of a governor for rpm than setting a fine/co@rse pitch

robban75
02-19-2006, 06:11 AM
Only do tests on the Crimea map.

From what we've gathered so far, the Tempest is 5-10km/h too slow between 1500 and 5500m, and its climb rate is 600-800ft/min too high at most altitudes.

ImpStarDuece
02-19-2006, 06:12 AM
Dont use IAS, use TAS from the no cockpit view.

Standard testing criteria are:

Crimea map (closest to standard atmosphere we have)
Noon
Clear weather
No wind (in difficulty settings)
100% fuel

VW-IceFire
02-19-2006, 07:22 AM
Originally posted by Witch_56_SqnRAF:
Well... Hmmmm.... http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

As a follower of 56 Squadrons history I'm pleased we have the Tempest, However...

Whilst learning this new plane I found it seemed a bit slow, I decided to do some more testing.

I flew several sorties with fuel loads from full to 25% fuel and default and no ammunition loaded. With these different loadouts the results were surprisingly similar.
I also used maximum power (9Lb's of boost) and varied the Prop RPM, which just slowed the plane down. I though perhaps the big Sabre engine could push the plane along faster with a co****r pitch, but no http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

I used references from a few places that had the historical data on the Tempests performance, most of these are in KIAS, MPH, TAS so I have simplified this below.

The speed for the Tempest @
Sea Level should be 326KIAS, I only managed to sustain 310KIAS

6,000' should be 367KIAS, I only managed 310KIAS

It appears that something's stopping the Tempest from sustaining any speed higher than 310KIAS.

?

As for the Radiator, it seems quite realistic that the engine heats up quickly.

As for the guns, these are the short barrelled Hispano Mk V's, much better weight of fire than the earlier Hispano but slightly less accurate as the barrell was around 10 inches (25cm) shorter, and they fitted more rounds in for each gun.
Has Il2 modelled these new guns ?

An excellent Tempest web site with comparisons with the Bf109K and Fw190D, pilots combat reports and much more http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://www.spitfireperformance.com/tempest/temptest.html

Once again, thanx for the Tempest <S>

Witch
Sounds like your measuring the IAS and not the TAS (True Air Speed). To do this you need to enable "wonderwoman view" and read the KPH off the dial there.

IAS and TAS diverge with altitude so depending on altitude you will have a similar IAS (if the engine can sustain it) but the TAS is radically different and this how top speeds are measured.

My test with the Hispano's indicate that they are belted properly with a full wartime 200 rounds per gun. Timing and perceived muzzle velocity seems to indicate they are Hispano Mark V's. I sent Oleg information noting this and I believe he's done the right and accurate thing. So not to worry.

My own and other speed tests indicate that the aircraft is performing very close to the rated speeds of a +9lb boost Sabre IIA Tempest V series II. So its not underperforming for the model that they have done for us...this is a good thing for sure as I'm always infavour of the closest accuracy to the tests. I'm not sure if we'll be able to persuade for a higher boost model later or not...upto the community to present a good argument for and support it properly with the data. Until recently I don't think we had that data.

SnapdLikeAMutha
02-19-2006, 07:43 AM
Originally posted by Chuck_Older:
http://forums.ubi.com/images/smilies/10.gif prop pitch is weird in the sim. For allied aircraft it seems to be more of a governor for rpm than setting a fine/co@rse pitch

That's how it chould be with a CSP (constant speed prop) system, you're setting the RPM you want the thing to turn at, the governor sets the actual pitch http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif http://www.avweb.com/news/maint/185020-1.html

It's funny that the forum will not let you say c o a r s e http://forums.ubi.com/images/smilies/88.gif

Witch_56_SqnRAF
02-19-2006, 08:36 AM
Guys, Thanks for the help and advice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Using the tips on testing settings, map etc, gonna give that a go in a minute.

Glad they're MkV Hispano's with correct ammo loads http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

As for the Engine, I "guessed" it was the Sabre IIB as it's a series 2 Tempest, no ?
The Sabre IIB had 11Lb's of boost and 2,420 bhp with a max engine speed of 3,850 rpm, which is nice. Although this could be an early series 2 Tempest with the Sabre IIa.

Confusingly I found this link to the Sabre IIA
http://www.spitfireperformance.com/tempest/sabrecurve.jpg
Which also states 11LB boost for the Sabre IIA ?

Perhaps we might get a better engine ?

WOLFMondo
02-19-2006, 08:50 AM
It matches pretty well with a 9lbs IIA engined Tempest V. Either one of the few in the first batch or one of the second.

I don't think anyone will argue a IIB 11lbs boosted Tempest isn't a valid request, if the right data can be found.

VW-IceFire
02-19-2006, 09:38 AM
Originally posted by Witch_56_SqnRAF:
Guys, Thanks for the help and advice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Using the tips on testing settings, map etc, gonna give that a go in a minute.

Glad they're MkV Hispano's with correct ammo loads http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

As for the Engine, I "guessed" it was the Sabre IIB as it's a series 2 Tempest, no ?
The Sabre IIB had 11Lb's of boost and 2,420 bhp with a max engine speed of 3,850 rpm, which is nice. Although this could be an early series 2 Tempest with the Sabre IIa.

Confusingly I found this link to the Sabre IIA
http://www.spitfireperformance.com/tempest/sabrecurve.jpg
Which also states 11LB boost for the Sabre IIA ?

Perhaps we might get a better engine ?
It seems to match Sabre IIA +9lb boost. So I'd say that its an early Series II aircraft or a retrofit of the earlier models.

What would be nice is to do the following:

Tempest Mark V, 1944 - Sabre IIA/+9 (as current)
Tempest Mark V, 1945 - Sabre IIB/+11

As far as I have seen and tested so far...the Tempest we have is excellently done. It matches up to the graphs of the engine and boost that we're guessing it is. As is...the current version represents the sort of performance available from April 1944 to December 1944. Some of the ADGB squadrons used 150 octane fuel and +11lb boost on the Sabre IIA's of Series I aircraft but this was V-1 chasing duties only.

Around December 1944/January 1945 they officially started using +11lb boost and 150 octane fuel although the Sabre engine was able to handle +11lb boost without the added octane level. The engine was quite remarkable if not somewhat tempermental...particularly with the dust and cold on the continent over the winter (lead to a number of engine fires and such).

So I think it'd be a valid request...there is precedent for such things...mostly with the FW190D-9 with its two models representing different time periods and fuel availability.

So if we can gather the right information then we can use both types in their historical settings whenever possible.

Willey
02-19-2006, 09:58 AM
310Kts is roughly 575km/h. I can get ~600 without problems, which is close to 326Kts.

Witch_56_SqnRAF
02-19-2006, 10:18 AM
It's still way too slow http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

Used the Crimea map with timings, outside view etc as advised above.

Speed at seal level raised to 315 knots it should be 326 knots so we're slow over 10 knots on the deck.

At 6,000' I only managed to sustain 310 knots instead of the 367 knots, so we're loosing more speed, 57 knots, @ 6,000'

As for the guns, how did you work out that they're Mk V Hispano's?

With the extra rounds of the mark V (200rpg)but faster rate of fire, 750rpm, there's 16 seconds of firing time, which is the same as the long barrelled Hispano II's as they fired at 600rpm and had 156 and 162 rounds per gun.

I agree that with 2 FW190D's and many Me109 versions we could have 2 Tempests, it would be nice to differentiate that last 6 to 8 months of the western air war when the fighting got harder and harder, and with 262's and He162's thrown in!

And it's a pity that, as far as production figures go, we haven't had a Typhoon for a long time now... but that's another thread http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kwiatos
02-19-2006, 11:32 AM
Did you set supercharger on 2nd stage above 3500m?

Alex_Voicu
02-19-2006, 11:52 AM
Originally posted by Witch_56_SqnRAF:
It's still way too slow http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

Used the Crimea map with timings, outside view etc as advised above.

Speed at seal level raised to 315 knots it should be 326 knots so we're slow over 10 knots on the deck.

At 6,000' I only managed to sustain 310 knots instead of the 367 knots, so we're loosing more speed, 57 knots, @ 6,000'


You need to use the rudder trim, otherwise the plane will fly slightly sideways and the max speed will be lower. Keep an eye on the side-slip indicator on the main instrument panel.
Here's my results:

Max speed @ sea level...............................605 km/h TAS
Max speed,supercharger M gear(@2100m).....652 km/h TAS
Max speed,supercharger S gear(@5600m).....698 km/h TAS

Witch_56_SqnRAF
02-19-2006, 12:15 PM
Hi,

I use the second stage supercharger around 10,000' when the boost level drops, to around 3LB's, and the second stage increases boost.

I have rudder trim on an axis and always keep it central http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Perhaps I'm flying over longer distances than you guys because it takes a while for the speed to drop from down to 315 knots, about 600kmh, on the deck ?

And you're converting ias into tas or does the outside view do that, I've mainly been checking speed at sea level so it'd be the same.

Thanx for the help and advice chaps http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

lbhskier37
02-19-2006, 01:12 PM
Are you using WEP?

Platypus_1.JaVA
02-19-2006, 01:31 PM
Originally posted by Witch_56_SqnRAF:


The speed for the Tempest @
Sea Level should be 326KIAS, I only managed to sustain 310KIAS

6,000' should be 367KIAS, I only managed 310KIAS

It appears that something's stopping the Tempest from sustaining any speed higher than 310KIAS.


http://www.spitfireperformance.com/tempest/temptest.html

Once again, thanx for the Tempest <S>

Witch
Uhm... your website shows speeds in MILES an hour and you state speeds in KNOTS indicated. (or seamiles an hour) Wich speeds did you use for testing?

Witch_56_SqnRAF
02-20-2006, 01:15 PM
Ahhhh, now I see, it's the "No Cockpit View", I'd never seen this view before, it's perfect for testing <S>

I can now achieve the correct speeds, and see exactly the speed in kmh, which is easy to translate into mph TAS or KIAS.

Apologies for doubting, even for a second, this excellent sim'

Thanks for all the help guys, and the patience <S>

Witch