P-51s

[TheWarrior 62]

Is it me or dose it seem the P-51 performance is a little lacking?    Biggest problem seems to sluggish and bleeds air speed to fast.  Faster than the P-47.  Big disadvantage in dog fight needless to say.  Any one feel the same?  Any one have any fixes?

[MAKO69 186]

What altitude are you dog fighting at?

[Wrench 9,847]

TK's prop FMs need work. This is a known thing. Spits and Skyraiders have the same issues (Skyraiders are also lacking the WEP they all used since the XBT2D)

 

I can almost bet the lift/drag tables are off. Unfortunately, I don't know enough about that to render a fix.

 

I take it you've been reading the DAT Forums about their new B/C models? (you know, the only difference between the B and C is the B was built in Inglewood CA -just down the road from me!, and C in Dallas Texas)

[Gatling20 753]

I agree, I have always found the stock TW P-51D  a very indifferent aircraft to fly. It is sluggish in acceleration, does not reach the published maximum achievable speeds at most altitudes, bleeds speed very quickly in any sort of turn, and can barely climb at all. I think the FM needs a serious overall. 

[TheWarrior 62]

MAKO69.  It doesn't seem to matter what altitude I'm at.  The performance is just bad all around. 

 

Wrench.  I see they have been busy over at DAT.  Can't download from there.  Maybe I should crawl back to them and beg.

 

Any ways.  I'll stick to P-47s and P-38 until the P-51 gets fixed.

[Wrench 9,847]

well, having had an in-depth look at the P-51B/C/Mustang III data inis, I can tell you with 100% certainty that they did almost EXACTLY what I did when I updated the original Wolf257 models (available here in the WW2 Fighters section). 

 

A copy/paste of the 3W P-51D's FM statements, with some modifications -- and mostly removed/commented out statements relating to higher mach numbers in the controls (ailerons, rudder, elevators) statements.

The only thing I haven't been able to pin down, is if B/C used WEP -- I'm reasonably certain later production models did, and it MAY have been retrofitted (like was done to Jugs).

 

I haven't had time to fully explore the new envelope, but can say the "new" Mustangs have a more 'slippery' feel to them, a LOT closer to what written accounts state.

I've made the same changes to the 3W D, but still need to test at standard combat configurations.

 

Remember, a LOT of the published data is for unloaded aircraft; full of ammo, fuel, external tanks 8-track players & tapes, performance WILL be reduced.

 

for those with the aeronautical bent, here's a site with more data (use the dropdowns at the top to select other aircraft)

 

http://www.wwiiaircraftperformance.org/

 

Warrior: Are you using the ones from here, SF2 updated? or the original 1stGens?

 

Anyway, when I get the 3W D tested a bit more, I'll post the data ini, so you all can wring it out.

[TheWarrior 62]

Hey Wrench.  I'm using the SF-2 ones.

[+baffmeister 1,205]

I always thought the TW P-51 was too sluggish as well but don't forget, it carrys a LOT of fuel so if you are in the habit of using the "Alt N" function you may want to consider loading only 50% fuel + drop tanks prior to departure.

I recall testing the AvHistory P-51 FM and it seemed to have much better performance. It would be interesting to try and port that FM over to the TW model but those AvHistory FM's are VERY complicated and I don't think it would be a simple task. May give it a shot at some point.

[Wrench 9,847]

don't forget, Hugh, GregoryP was building "1%" FMs.  Yes, they're VERY complicated!!!

[TheWarrior 62]

Last night I was playing around with the SF2 P-51B and found the performance for it also was lacking.  Then I took the P-51C for a spin and talk about night and day.  The C doesn't lose air speed as fast and when it dose it regains it pretty quickly when you level out.  Much better in the C as apposed to the B and TW P-51D.  So I copied and pasted the DATA file from the C to the B.  By the way they both use a P-51B DATA file so there was no renaming required. 

[+baffmeister 1,205]

A very quick FM update for ThirdWires P-51D attached. For WW2 use it will require some edits to the date range etc. I decided to try and reverse engineer a "fix" to try and get performance closer to book numbers. My suspicions about this FM always centered on the very high CDL number for the inner wing section so I have messed with that to try and generate sea level speeds closer to what is published. [ around 375mph at sea level with WEP] Some other changes made including rudder edits.

 

When I adapted the ThirdWire Spitfire IX and S-99/199 FM's for WW2 use they seemed to work very well. With new engine tables and some minor edits I had no particular problems matching performance numbers for the Spitfire 1a and BF-109E's. The P-51D is way more difficult so I think a "mistake" was made in the FM. Anyway, I plan to do some more work on the P-51D for KAW use but for now here is an early beta tester.

P-51D_FM0.90.zip

 

[TheWarrior 62]

Just completed an escort mission flying P-51D with Baffmeister's P-51D DATA.ini and WOW.  Much better.  I felt like a predator and not a sitting duck.  Usually in my mission with the stock TW P-51Ds, my squadron would get torn to shreds.  On this mission.  Eight kills to no losses.  One P-51 damaged.  On the down side though.  Lost seven out of 15 B-24 going into the target area.    Not to sure what happened there.

[+RAVEN 414]

They got shot down maybe?  Just kidding, I'm going to try Baffmeister's P-51D DATA.ini on my A-36A when I get to 'Beta' with the model, Not sure what to set the amount of drag for Dive Brakes yet.

[Wrench 9,847]

well, safe to say The Warrior isn't flying for the 99th FG!!!

Odd, though about the differences in my B & C models ... I thought I'd done them exactly the same!

 

Raven, for my version of the Apache, iirc, I used the dive brake specs off the A-4 !!

 

don't forget, the Allison isn't going to have the altitude performace, but SHOULD stay with or beat the Merlin 'stangs below 15K

[+RAVEN 414]

Thanks Wrench, I haven't look at data yet, I'm still collecting research material , detail drawing and pic's and showing vertex's around, Oh and reloading the backup Max file a lot :)

[Gatling20 753]

Just tried baffmeister's new P-51D FM.

MaxSpeedSL= 225.75 meters per second at sea level (505 mph) seems a bit much for a P-51D.

The CDL changes make it climb a bit better, though.

[TheWarrior 62]

Hmm.  Looks like we need knock some speed off.

Edited May 23, 2014 by TheWarrior

[+baffmeister 1,205]

Just tried baffmeister's new P-51D FM.

MaxSpeedSL= 225.75 meters per second at sea level (505 mph) seems a bit much for a P-51D.

The CDL changes make it climb a bit better, though.

The 505 MPH is the redline indicated airspeed for the P-51D. [ found on the internet] The present drag on the FM won't allow it to go that fast during level flight at sea level but should be attainable during dives. During my rather informal tests I was getting about 370 MPH with WEP at sea level. [75% fuel, clean.] I haven't run any speed tests at altitude yet but assuming the ThirdWire engine table is OK the speeds should be reasonably close. I guess one thing to watch for is if the AI aircraft show any signs of unrealistic speeds at low altitude. My understanding is the AI uses a simplified flight model so there is some potential for issues.

Edited May 23, 2014 by baffmeister

[Wrench 9,847]

Something fun for you all to spend the weekend reading!

 

Remember like the B and C, the D was built in Inglewood, CA, and the K in Dallas, TX

Other than that, same aircraft.

 

Enjoy!!

 

And speaking of the new test FM, I'd change the WEP start throttle position to

 

WEPThrottle=0.95

 

might make it "last" longer. 0.99 would be better, but I don't think it'd allow that.

The section in the manual on WEP is informative.

 

 

[+baffmeister 1,205]

Love them flight manuals, Thanks!

[ShrikeHawk 384]

Here's another P-51 FM to consider. It's part of my ww2 Europe install where I have re-tuned all the FMs. With this FM, you'll find your AI wingmen are much more aggressive. It's designed to match up well with the re-tuned Fw-190A FMs which are very aggressive in the BnZ realm. This FM uses the AvHistory Merlin sounds.

 

Mustang.zip