Recently I found a new speed tech while researching the game. I made a tutorial for this technique here:

I forgot to mention that the wall exploit doesn't work in downhill or uphills.

If you'd like to use to play with the in game variables showing on screen, you need to download BizHawk and then download this lua script: https://github.com/mateusfavarin/TSR-PS1-Tools/blob/master/BizHawkScripts/tsr_display.lua

Here's a lap example using save states that shows the techniques applied. This speed tech can save over 1s in multiple lap time trials.

I hope that this tutorial helps runners and future runners!

Amazing! :D I did the stair strat in my runs, good to know it's not just placebo