So you're faced with a problem 
You just got a sick time, and you want a video of it to show with the world, but
nobody wants to record your run 
You could always record it yourself with dolphin, you've seen people do that, but you're rocking a hot potato as your PC and can barely hit 10fps...
Well its your lucky day, because in this elaborate or maybe not so elaborate guide (idk I haven't written it yet) I'm going to introduce you to the wonderful world of frame/audio dumping and sexy ass TT's on a shitty ass PC

First of all, shoutouts to Bynt for teaching me like 99% of this dolphin recording stuff and shoutouts to Invincible and FoxAmexion for introducing me to frame/audio dumping

So this is cool and all, but what is dumping? Well it works a little bit like this:
- You download your ghost
- You use live replay to record your ghost in dolphin
- Your PC sucks ass, so its now playing in 10fps
- After waiting for 10 minutes for your run to finish playing extremely slowly, out pops the final video and audio, except the audio is great, and the video looks hot af
So enough chit-chat, on to the tutorialStep 1 - The Setup1)
Install Dolphin2)
Download WiiScrubber3) Get a .iso of the game
4) Download the ghost (or ghosts) you want to record
Step 2 - Preparing the Ghost File1) Find the corresponding track ID for the ghost you're recording
here2) Rename your ghost file to ghost1_comp_<trackid> (so for example for DDR, ghost1_comp_13)
3) Create a copy of your renamed ghost file and name it ghost2_comp_<trackid>
Step 3 - Wiiscrubber1) Unzip WiiScrubber
2) Open up the folder and run MakeKey.bin following the instructions it gives you
3) Run WiiScrubber
4) Click the "Load ISO" button in the top left and select your totally legit and legal MKWii.iso
5) Navigate to Partition 1 > Race > Time Attack > Ghost 1, and replace the ghost that matches your track ID with your own ghost1 file from step 1
6) Repeat the previous step but instead of Ghost 1, select Ghost 2
Step 4 - Using Dolphin1) Launch dolphin
2) Double click the center where it says No Directory
3) Select the ISO and a banner should pop up that says Mario Kart WIi (if the game opens simply close it)
4) Click the graphics button in the top right and chose the graphics settings you want
5) Click the config button in the top right and enable cheats
6) Right click the Mario Kart Wii banner and click properties, then go to Gecko Codes and click Edit Config on the bottom left
7) Copy + Paste the contents of your iso regions gecko codes into the config file
Gecko Codes:
PALNTSC-UNTSC-JNTSC-K8) Enable all the gecko codes (uncheck no music if you dont want custom music later in editing)
9) Run the game and select the track you want to record, your ghost should have replaced the staff ghost (make sure to pick the same character/vehicle combo)
Step 5 - Frame/Audio Dumping1) First of all, navigate to the ghost you want to record and select "Race this Ghost"
2) After about .2 seconds you can go out back to the ghost selection. We want to record with "Solo Time Trials" so we dont have "+0:00.000" appear on our screen
3) Before you actually start the replay, pause dolphin
4) Click "Movie" on the menubar and select "Dump Frames" and "Dump Audio"
5) Press play and continue with the replay, its now recording
6) Once the replay is done, repause dolphin and uncheck both "Dump Frames" and "Dump Audio"
And that's it! You're almost done!
All that's left to do is to put the audio and video files together and you'll have your own high quality recording
On Linux you can find the video at ~/.local/share/dolphin-emu/Dump/Frames/framedump0.avi and find the audio at ~/.local/share/dolphin-emu/Dump/Audio/dspdump.wav
On Windows you can find the video at C:\Users\Owner\Documents\Dolphin Emulator\Dump\Frames\framedump0.avi and find the audio at C:\Users\Owner\Documents\Dolphin Emulator\Dump\Audio\dspdump.wav
For Mac users, it should be in a similar folder but I don't have access to one atm so I can't check (someone please reply to this with the file locations) however I would imagine that you could find the dolphin folder in ApplicationSupport/
I should probably mention now that there is also a dtkdump.wav audio file but you can just ignore it
Edit: The video that will be output will not be in 1080p 
If you want 1080p you need to do that with your video editor, for example I used to use kdenlive so I would set my preset to "1080p 60fps"Edit 2: Ignore the above edit, that only happened because I didnt actually have dolphin open in fullscreen. Make sure you have it open in fullscreen

Hope this helped