Website for comparing Power/Weight of any Piston Aircraft

Would you use this website when it becomes available?
  • Yes
  • No
  • Yes, but only if jet aircraft are also included
0 voters
Do you prefer it as a website, or a desktop app (updated manually by downloading)?
  • Website
  • Desktop app
0 voters

I’m making a website for comparing Power-to-Weight ratios of any piston engine aircraft in the game. I am curious how useful it is to the community, so please vote and leave your feedback. I will know whether to put it online first or to first improve it.

The website allows you to see at which altitudes your plane performs best vs planes you struggle fighting with.

1. Here’s how to use it:

Let’s say you’re in a La-7 at 5000m and you encounter F8F-1 at the same altitude. You can’t run because F8F is always faster, and you can never outclimb it. The only choice is a dogfight… but at what altitude?

You learn that by choosing those planes from a dropdown, choosing a speed of dogfighting (usually 300-400kph) and pressing “Calculate!”.

Shown on the user interface

GUI_use_example

Default values of other settings are fine (30% fuel means min-fuel). A new graph appears with Power-to-Weight ratio of La-7 and F8F-1 across 0-10000m:

La-7 has the biggest advantage from 200m to 1km and from 5.4km up. On the other hand, F8F gains a considerable advantage between 2km and 4km.

Therefore, it’s best for you to force the fight above 5km, if the battle situation allows for that. Alternatively, dogfight while diving to 200-1000m and fight there, but not below that, because F8F-1 starts gaining power near the deck on its 1st supercharger speed.

2. Website features:

1. Graphs of Power-to-Weight ratio. (click for an example)

2. Graphs of engine power. (click for an example)

3. Any piston engine aircraft in WT can be chosen from a WT-looking dropdown. (click for an example)

image

  1. Choosing airspeed, altitude, power mode and air temperature because they affect engine power.
  2. Changing fuel amount because it affects weight.
  3. Speed in kph, mph or kt, altitude in m or ft, temperature in °C or °F.
  4. Hiding and showing graph lines of particular planes, by clicking on them in the legend.
  5. Graphs are downloadable as .png.

3. Why make this website:

To create a comprehensive, objective, automatically updated source of info about WT aircraft performance, with climb-rate and top speed graphs being the end goal.

There are no such sources:

  • In-game statcards are notoriously inaccurate about most things they state, and information is very limited.

  • WT wiki has the same issue but also has subjective opinions about aircraft, which are frequently wrong.

  • Forum datasheets:
    Air RB - Game Mechanics Guide
    Aircraft Data Sheets - War Thunder - Official Forum
    are by far the most comprehensive and close to the truth, good info sources. Unfortunately, sometimes they are outdated because planes aren’t re-tested after updates in flight models. Sometimes, incorrect information is present in them too. They also don’t provide information about Power-to-Weight, optimal altitude ranges for fighting, or ways to easily compare planes, which this website does.

This lack of comprehensive info leads to spreading of misinformation of forums, discords, YouTube etc. which contributes to players not being as good as they could and suffering as a result.

4. When will it be available:

In 2-6 months, depending on the feedback, but it might take longer. Of course, the engine power and weight calculation scripts will be open sourced on GitHub. Upon release I’ll make a Discord server for this project, for anyone interested in it and also for figuring out the problems described in 5. Limitations and future improvement.

I’ll be happy to hear your feedback about this project. Whether it will be useful to you or not, what would you change in it, or whether you’d like to help in developing it after release.

5. Limitations and future improvement:

Things described below won’t be implemented quicky, they could take many many months to figure out.

For the curious

Power to weight ratio isn’t perfect in telling which plane is better in producing excess energy; it doesn’t take into account propeller efficiency. That’s why many US fighters with very good propellers, like P-51s, P-47s and F4Us look a bit worse on the graph than how they perform in game. And planes with inefficient propellers like biplanes, M.B. 157 or La 5, 7, 9, 11 look a bit too good.

To solve this, prop efficiency needs to be calculated to get Thrust-to-Weight - a better metric than Power-to-Weight. However, calculating it based on Datamine files appears to be extremely difficult, because propellers are modelled accurately with many parameters. I’m not aware of anyone in the community who managed to do that, so if you work on it or know someone who does, please let me know!

Even with Thrust-to-Weight ratio you can’t estimate climb rate or top speeds, because it doesn’t take into account airframe aerodynamics at all. Planes with low induced drag are underestimated when you want to estimate climb rate, and ones with low parasite drag are vastly underestimated when you want to estimate top speed.

To solve this, one needs to calculate induced, and parasite drag at different °AoA, based on Datamine files. Fortunately, Hadi and @praetоrii managed to do this in a form of a Discord bot: Hadiiiiiiiiiiiiii/AlexStillTalking: A Discord bot that supports various War Thunder data mining features, such as creating jet thrust graphs, weapon presets, flap rip speeds, and comparing game files from different game versions. (github.com)

It’s a big achievement that more people should be aware of. It also models thrust of jet aircraft, so all pieces needed to estimate jet top speed and climb are are there. It needs help in development via contributions on GitHub. It’s a great jet equivalent to my propeller aircraft focused website, and it’s available on DEFYN discord in botting.

6. What else is it useful for:

For the curious

You can find which variant of a plane is better (works best if planes are similar). Let’s say you want to check how big of an improvement Yak-3U is compared to Yak-3, and if it’s worth it to get a Yak-3 (VK-107), since you only care about performance:

Well, Yak-3U has much better hp/kg vs Yak-3 so it’s clearly a much better plane, since the airframe and therefore manoeuvrability is similar. Yak-3 (VK-107) is only better in a 3-5 km range, while Yak-3U offers better performance everywhere else. So, if you only care about performance, then Yak-3 (VK-107) is not worth it, since currently both are at 5.7 Br.

7. How it was made:

For the curious

It is written in Python, and it reads files from flightmodels and flightmodels/fm directory from gszabi99/War-Thunder-Datamine (github.com). Parameters from the files are used to calculate engine power and a graph is made. I validated it by comparing calculated power to actual power logged while climbing in test-flight. I did it with around 60 planes using WTRTI (mesofthorny.github.io), and on almost all planes the model is within ± 1% margin of error. Only in Tu-1 and P-63s error increases to ± 5%, but there might be more errors I didn’t notice.

Overall the whole engine power calculation is surprisingly complex. There are a lot of parameters in FM files that affect:

  • critical altitudes
  • how change in RPM and switching to WEP changes critical altitudes and power output below them,
  • curvature below and above critical altitude
  • the effect of speed on critical altitudes (RAM effect)
  • and much more

It’s weird how simply all jet engines are modelled compared to piston engines.

27 Likes

Would be an incredible addition! +1

4 Likes

This is awesome. Well done man

1 Like

Do you think you can also add a plot of the max speed in function of altitude? that would be extremely useful.

1 Like

I see this as a great thing for players who will want to be interested in how to use the strengths and learn the weaknesses of the planes.
For players who fly near the ground, in the middle of the map and are out of the game within two minutes, it probably won’t be…

2 Likes

Awesome mate, looking forward to play around with it!

2 Likes

very nice

prop efficiency sometime soon

2 Likes

I wish. That is one of the end-goals of this whole project. But as i described in 5. Limitations and future improvement: It is very difficult to do, mainly because I’d need to calculate propeller efficiency based on those datamine files. And that seems very dificult, cause propellers are moodelled in a very complicated way to me.

You’re incredible for doing this. I hope you’re able to succeed. Good luck!

1 Like

I think that ignoring prop efficiency as a first approximation would be good enough. There will be some errors but it can still give a general idea.

I’d like to see this but with a raw thrust / hp output instead of T:W.

prop efficiency is vital to getting thrust which is vital to getting top speed, there’s no other way to calculate around this with the values gaijin has given

1 Like

Raw power is available. Click on " 2. Graphs of engine power." to see an example. Getting thrust will take a long time, if succesfull at all, cause it’s very difficult.

1 Like

That’s great, I haven’t personally tested it so I wouldn’t have known.

1 Like

I’m not stating the opposite, but we don’t really need exact quantitative results. Qualitative figures are enough. After all, ww2 constant speed propellers had mostly similar performances and assuming them identical as an early stage approximation would still produce significant results.

1 Like

Usually, propeller efficiency between 200kph - 600 kph, depending on a plane varies between 60% and 90%, with 75-85% being most common. Assuming an average 85% with some artificial dropoff at very low and very high speed wouldn’t be too bad. I guess it would lead to under or overestimations of top speed by + - 5%, maybe more, maybe less.

We might try it, and see what are the results compared to top speeds from data sheets.

2 Likes

Alpakinator,
I’m happy to help with whatever you might need or if you want to get on discord and go over some observations I’ve made while testing/flying.

It’s very easy to get pulled into granular details of the game mechanics and aircraft performance. Personally, I tried to distill meaningful information to applicable performance gains with minimal impact on situational awareness.

Also, beware the gaijin… they constantly change/break things in game mechanics with zero notice. One of these examples of breaking things was contrails, when they updated the contrails, the speed at which they manifested was 50-100kph higher for all aircraft. For that to be so uniform accross all aircraft was suspect to say the least.

Reporting obvious errors in game that could be easily patched fell on deaf ears, which is why I stopped updating my previous guide. So like I said at the start of this reply, I’m happy to help, but be aware that gaijin will make this harder than it should be and ,from past experience, obstructive/unhelpful.

best,
Mobb

2 Likes

I just wanted to tell you I still use your guide for at least a place to start when learning what mec settings to use for an aircraft. Its a damn shame gaijins behavior pushed you into discontinuing your guide.

Thank you for the kind words. 07

1 Like

Announcement everyone! I finished version 1.0 of the website. It’s online. Here’s the link:

Details in the README of the Github repository (link on the homepage).
Enjoy!

1 Like