2022-11-19: Tested this datapack on Minecraft 1.19.2 and updated the descriptions below. Still going on some performance and feature improvement works, and stay tuned for the next update soon!

Update v2.3.3b (2022-01-29): Fixed a long-existing issue on PaperMC 1.16+ servers where minecart speed used to be sometimes unexpected. Enjoy this update on your latest PaperMC server~~ 😀

Update v2.3.3 (2022-01-22): From now on, you may set the maximum allowed speed for an individual minecart. Also, now there is a way to run your minecarts on curved tracks at a speed up to 140 km/h! See on the update logs for the details.

Introduction

Downloading this datapack

If you would like to also make your railway system fully-automatic, or if you wonder how fast you are, you may install the other two data packs above, and then run them simultaneously in your map. For how to install the datapack(s), please refer to this page for more information.

Features

• "Color-driven" speed control. Controlling minecart speeds using this tool mainly depends on some concrete blocks (or concrete powders) in specific colors, which means that you don't need to type any advanced commands manually. The only command block you need to place is the "high-speed mode" command block, while its command is automatically generated already, depending on the direction you place it.
• Maximum minecart speed available: 999 km/h.
  • This value is configurable by a scoreboard manipulation command, which is useful if your PC or server connection is not powerful enough. Please refer to the FAQ section for how to configure.
• Customizable acceleration. The acceleration/deceleration of the minecart can be chosen to one of the following options:
  • Regular minecart: 4.0 km/h per second.
  • Smooth minecart: 2.5 km/h per second.
  • Turbo minecart: 10.0 km/h per second.
  • Super-turbo minecart (old-version compatible): 20.0 km/h per second.
• Easy to install, as it's a data pack designed for Vanilla Minecraft. Check out this page for how to install this tool.

All Tools Available in This Data Pack

• High-speed mode command block. Place it in your desired direction to indicate where the minecarts will go. Once a minecart steps through this command block, it will be switched into "high-speed mode", so you may then control its operation speed.
• Color concrete blocks placed beneath the rails, where high-speed mode minecarts start to smoothly change their speed.
  • All concrete blocks available:
    • Green concrete block: +50 km/h.
    • Lime concrete block: +10 km/h.
    • Yellow concrete block: -10 km/h.
    • Orange concrete block: -50 km/h.
    • Green concrete powder: +25 km/h.
    • Lime concrete powder: +5 km/h.
    • Yellow concrete powder: -5 km/h.
    • Orange concrete powder: -25 km/h.
    • Red concrete block (powder): Turn off high-speed mode.
    • Blue concrete block (powder) ^[​v2.1+] : Immediately set the minecart to current speed limit without gradual acceleration.
    • Magenta glazed terracotta (i.e. arrow block) ^[​v2.1+] :
      Usage #1: Put it right beneath the track to teleport the minecart by a perpendicular direction in high-speed mode (see here for an example).
      Usage #2 ^[​v2.3.3+] : Put some of them next to curved tracks to enhance the maximum operation speed to 140 km/h (See on this example and FAQ question 2 for more information.)
  • When your minecart speed is expected to be beyond 70 km/h, it is suggested to place several same-colored concrete blocks in a row to ensure that they can be detected by the minecarts.
    • Example in this video: placing 8 orange concrete blocks in a row
• Debug minecarts, specially designed for testing whether your high-speed minecarts are working properly. It provides some detailed information, so you can adjust your concrete blocks to accurate locations according to the generated messages. Debug minecarts are available in both English and Mandarin Chinese versions.
• You may integrate this tool with the FTMC Railway Builder datapack and/or the Speedometer datapack. All these three data packs works independently, while they can be also used together with each other data packs depending on your demands.
• See on the showcase video available on this post for how to utilize this datapack.

FAQs

1. Does the "FTMC Bullet Cart v2.3 Engine" and "Instant High-speed Railway Builder Tool" refer to the same data pack?
   • YES!! 😊
   • From Feb. 10 2021 on, the latter name "Instant High-speed Railway Builder Tool" is no longer shown on the title, and it is suggested to just call it the "BulletCart v2.3" data pack.
2. Can minecarts in high-speed mode pass through any curved rails?
   • From version 2.3 on, YES! But, be sure that your minecart speed should be no more than 70 km/h (when on straight rails), otherwise it may still derail.
     • For U-turns, please reduce your minecart speed to 35 km/h (or lower) to avoid derailment; for other regular turns, 70 km/h speed is acceptable.
     • From version 2.3.3 on, you may improve the curved tracks by putting some magenta glazed terracotta blocks next to it (here is an example of the usage), and your minecart will be able to run at a maximum speed of 140 km/h. (Note that this way is still not applicable to abrupt L-turns and U-turns.)
   • WARNING: Old version of this datapack does not support curves on high-speed mode. Please update it before running your high-speed carts on the curves!
3. Can minecarts in high-speed mode pass through any slopes?
   
   • From version 2.1 on, YES! But, when your minecart speed is beyond 70 km/h, it still cannot pass through consecutive slope rails, or it will be too steep, and there will still be risks of derailment.
     • Precisely, for any minecarts not faster than 72*n km/h, please ensure to build at least n-1 straight rails between every two neighboring slope rails, which makes the overall gradient not greater than 1/n.
   • WARNING: Old version of this datapack does not support slopes on high-speed mode. Please update it before running your high-speed carts on the slopes!
   
   
4. Could I stop a minecart in high-speed mode using the Minecart Launcher Command from the FTMC Railway Builder Tool?
   
   • From version 2.3 on, YES! But, be sure that your minecart speed should be no more than 70 km/h (when on straight rails), otherwise it may still fail to detect the launcher command.
   • WARNING: Old version of this datapack does not support this feature.
5. Do I still have to boost the minecarts by powered rails even if they are in high-speed mode?
   • Not necessary. Until the high-speed mode is over, whether or not powered rails are used on the way, the minecarts are always fully powered.
6. Could I test these data packs in my server?
   • Of course! They are expected to also work in Vanilla or Spigot servers on Minecraft 1.14+ and 1.13.x versions. Also, please comment below for any suggestions or issues. 😉
7. Could I use these data packs on MCPE / Bedrock Edition?
   • Sorry, but MCPE / Bedrock Edition does not support data packs. In my future plan, I might take a look at how to re-design this tool in Bedrock Edition add-ons. Stay tuned~
8. I used this data pack in my 1.14.x map (or server) before, and I'm gonna upgrade it to 1.15+. Do I have to update this data pack as well?
   
   • Not necessary. But please note that you'll still need to upgrade the FTMC Railway Builder Tool data pack if you are also using it in your project.
9. I used this data pack in my 1.12.x or 1.13.x map (or server) before, and I'm gonna upgrade it to 1.14+. Do I have to update this data pack as well?
   • Yes. Please update this datapack. You will find the corresponding datapack(s) from this link.
10. Looks like my map sometimes freezes when I am on a very high-speed minecart. Is there any way that I can reduce its speed?
    • From version 2.3.2 on, YES! You may configure the maximum BulletCart speed allowed in your map. For example, if you desire to limit ALL of the minecarts in your map to be within 123 km/h, Please enter the following command in the chat:
      /scoreboard players set #ftbc_config BCartMaxSpeed 123
    • The value of "BCartMaxSpeed" is set to 999 by default, and it can be any integer between 1 and 999 (inclusive).
    • From version 2.3.3 on, you may also set the speed limit to an individual minecart, for example:
      /scoreboard players set @e[type=minecart,distance=..2,limit=1] BCartMaxSpeed 123
11. Is it possible to control the speed of my BulletCart through only commands and without the color concrete blocks?
    • Yes, but NOT recommended for beginners, unless you manage to maintain multiple sets of speed limits on the same track for different train types (ex: express trains and commuter trains.)
    • Currently, to control the speed limit by command block, you'll need to manipulate some internal scoreboard values, as I technically did in the Republic of FlashTeens map.
    • To set the speed limit to N km/h, you have to specify a value of (N − 29) to internal score "ftbctargetspeed". For example, the following command will apply to a BulletCart with tag "your_tag" and set its speed limit to 100 km/h:
      scoreboard players set @e[type=minecart,tag=your_tag,limit=1] ftbctargetspeed 71
    • If you need to apply this command to a minecart which is just enabled the BulletCart (v2.2+) mode, but not yet set the speed limit through color concrete blocks, then it is considered as an un-initialized state. For this case, you'll have to apply another command below as the 2nd command to initialize the BulletCart and actually accelerate the minecart:
      tag @e[type=minecart,tag=your_tag,limit=1] add ftbc_v22_has_init_speedlimitAlso, to optimize this mechanism, you may compact the two commands above into an mcfunction.
    • In the future, I will consider adding some extra features to help you deal with this possible need in an easier manner. Stay tuned~ 🙂