Sea Level Acceleration Revised For 2.07

[Nashwan]

Same book has the Spit 16 at 8,288.5 (take off) for an LF Mk XVI.

I just checked in Spitfire the History. They give figures for 3 Spitfire XVIs weighed, one was approx 7,400 lbs, the second approx 7,500 lbs (with a modified radiator) (which is expected because the Spit XVI was a Spit IX with a US made engine). However, they also give a figure for SM 410, approx 8,300 lbs. SM410 was fitted with a bubble canopy and a 67 gallon rear fuel tank, the 8,300 lbs weight included full fuel in all tanks, including the rear tank.

In other words, the Spitfire XVI should weigh approx 7,400 lbs, only with a rear tank does the weight go up to 8,000+ lbs.

[Speed55]

Thanks to all of you who are doing this work!

[MOSQ]

Hammer,

All my Accel testing is at 500 ft. However I have more than the usual tests, I have w/wo Gondolas on the 109s, 6 vs 8 MGs in 47s ect.

I'd be happy to  collaborate with you. I have to admit I'm not fired up about redoing all the tests right now because I'd bet HTC is going to redo the drag model again soon.

I did it in AHI, then AHII changed the numbers. Redid it for AHII, now 2.07 has changed it again. Pyro has said the drag model is wrong for the P-38, so I'm waiting for that to be changed.

But I did go ahead and do the sustained turn testing. WW pointed out I wasn't hitting the max rate, so I'm 2/3 of the way thru redoing that. Once it's done I'll repost it in this forum, and if it passes peer review here I'm hoping you'll post it on NetAces.

Dok, if you can get your charts to work at NetAces, I'd be happy to supply my part of the data.

[DoKGonZo]

How do you like it so far:

Demo 2

The only real restriction is just one datapoint per plane. So basically pick the most common MA configuration (3-cannon La7, 8-MG P47, etc.). And the plane names in the CSV need to be normalized, I already have a translation table to expand these to the full names for display.

This is now reading the raw CSV data with nomalized plane tags.

I replicated the first chart just for the purpose of tuning the layout.

It can handle combining data from multiple CSV's, and directories. So if you wanted to have a chart with data that MOSQ and Widewing compiled independantly, and uploaded to their own dirs on a ftp server, it's only like 3 or 4 more lines of code in the data-builder than is normally needed to build a dataset for a particular chart. I built this to be easy to modify as opposed to the most elegant thing on earth.

Adding a chart to the console is easy. I've condensed that down to a 1-liner. The tricky stuff is in the data-builder PHP file which grabs the raw CSV and builds the data set to send to the chart display. It's not that bad, but it does require some basic programming skills to deploy a new dataset. No real way around this.

There are no database or file-writing requirements. So this should pretty much run anywhere. If the concensus is to host at netaces, then I'd treat the installation on my server as a perpetual beta release and send updates to the netaces guys whenever I added a feature or a new dataset.

I'll probably add a PayPal Donate button - the freeware version of this charter has the default link back to their site. So if I get enough donations I'd put that towards a license to get rid of that.

[hammer]

DoK,

Looks good. No need to host at netaces, it was just an offer. I can link to anywhere.

When I get home, I'll post the spreadsheets I made with speed and climb data and send you the link. They are based on the new charts, not on tests.

[Mister Fork]

Good work WideWing.  My earlier tests are definately different from these ones.  Great work!

[DoKGonZo]

Originally posted by hammer
DoK,

Looks good. No need to host at netaces, it was just an offer. I can link to anywhere.

When I get home, I'll post the spreadsheets I made with speed and climb data and send you the link. They are based on the new charts, not on tests.

Thanks. Once I get a few data sets in there I'll have a better handle on how to build the various kinds of charts.

I've tweaked things a little more since earlier today:

- Added a linksbar include to allow easy adding of link-outs
- Tweaked the CSS for better readability
- Added ability to include notes/credits for each chart
- Various internal modifications so I don't gotta type as much to add new charts

Once it goes live I'll rig a support forum ... and a debug install, and upload account so that the data gurus can upload and test stuff.

[Spatula]

I read on a post a little while back that the climb figures bare a direct relationship to the accleration figures - eg they're really one in the same.
So why not just use HTCs graphs for acceleration data?

Im not trying to belittle anyones effort. Its a genuine question.

[bozon]

Spatula, climb is proportional to acceleration but depend on the speed.

The HTC climb charts are done at some given speed (plane auto-climb speed?). So the climb rate is proportional to the acceleration at that speed (normally 160-180 mph).

WW's test measures averaged acceleration over the 150-250 mph range. If he'd use a higher upper speed the order will change dramatically and will favour the planes with higher top speed. Consider an extreem case in which you measure acceleration around 350mph sea level. Spit 16 will not accelerate as this is about its top speed, but P51 will still be accelerating.

Bozon

[Spatula]

Cheers Bozon, explained like that, it makes pefect sense - thanks

[hammer]

DoK,

You have a PM.

[DoKGonZo]

Originally posted by hammer
DoK,

You have a PM.

Thanks ... I'll work on that data this weekend ... and whatever else I get between now and then.

I'd love to see a dataset on lethality. Specifically:

• max lethality at takeoff for "typical" loadout (i.e. no gondies, just max internal guns).
• number of seconds of firing secondary weapon (i.e. how long do the cannons last?)

Based on those cool dispersion charts I saw at netaces (I think) we could probably even take a stab at "effective range."

[hammer]

Here is my Weapon Lethality Page. It's based on how many rounds it takes to kill a fighter hangar with a .50 cal being a "1". I am partially finished with a plane lethality rating based on these numbers. I'll finish it up and post it.

[DoKGonZo]

Cool ... that's probably close enough ... I'll look at an Excel version too.

[Widewing]

Originally posted by bozon
Spatula, climb is proportional to acceleration but depend on the speed.

The HTC climb charts are done at some given speed (plane auto-climb speed?). So the climb rate is proportional to the acceleration at that speed (normally 160-180 mph).

WW's test measures averaged acceleration over the 150-250 mph range. If he'd use a higher upper speed the order will change dramatically and will favour the planes with higher top speed. Consider an extreem case in which you measure acceleration around 350mph sea level. Spit 16 will not accelerate as this is about its top speed, but P51 will still be accelerating.

Bozon

To provide examples of the differences in sea level acceleration based upon starting speed, here's some data I took measuring time to accelerate from 200 mph to 300 mph. Same criteria as before, 50% fuel regardless of capacity. Understand that not all aircraft can attain 300 mph at sea level and some barely get there. The Bf 110C-4b required almost 2.50 minutes to reach 300, largely because it can only manage about 302 mph at sea level.

Those tested represent a sampling only, with some slow-pokes thrown in at the end for perspective.

In descending order, from fastest to slowest tested.

Type/time

Tempest: 25.97
La-7: 27.87
Bf 109K-4: 28.50
Spitfire XIV: 29.44
F4U-4: 30.07
Spitfire XVI: 31.53
Bf 109G-14: 31.62
La-5FN: 31.62
Fw 190D-9: 31.63
Typhoon: 33.98
Ki-84: 35.44
Spitfire VIII: 35.60
Yak-9U: 36.19
Bf 109G-2: 37.22
P-51D: 38.16
P-47N: 38.31
P-38J: 39.06
Bf 109G-6: 39.91
Bf 109F-4: 41.41
N1K2-J: 42.91
C.202: 57.89
Bf 110G-2: 67.01

Note that the Spitfire Mk.XIV now accelerates faster than the Mk.XVI.

My regards,

Widewing