In Mario Kart 8 (I'm playing Deluxe on the Switch but I guess it's the same either way), when you go over a jump, you can also press the jump button, and if you time it right, you get a speed boost.
You can also push the left stick in a direction at the same time to make the jump more stunty: your character might stand up in the seat, or roll.
Is this change when you use the stick purely to animation, or does it have any effect on the gameplay (such as increasing the amount of boost)? If it has an effect, does it make a difference which direction you push, and if so, what's the best way to do it?
Best Answer
In short: Direction does not impact it, these are just new animations and it is just a boost when you land still.
As seen here (and my own experience with Mario Kart games that implemented this):
There is some more detailed information there about combos, trick types and the history of it.
To clarify as per my understanding about the above quote - performing consecutive tricks (jump boosts) in a row will increase your boost and extend it. Repeatedly performing tricks off jumps in quick succession, not multiple tricks in the air.
Another source:
This source showcases a lot of different jump animations, which further solidify the idea that these are just for showboating and fun.
And finally there is another wiki that states: