Forward shell hyperspeed
When jumping while riding a shell, Mario's speed is not reduced by 20% as for regular single jumps. In riding shell ground action, Mario's speed is capped at 64 (+ 1 frame of slope acceleration), but if Mario jumps on the frame he touches the ground, the cap doesn't take place and Mario continues to accelerate.
The most speed that can be obtained with this is 282-400, depending on the wall angles and projections[note 1]. The speed is gained via air acceleration, which increases Mario's speed by 0.15 every frame.
- With axis aligned walls, the most distance Mario can move while still hitting both walls is when facing exactly 45° into the referenced wall, allowing 200*sqrt(2) ≈ 282.84 speed. With perfect wall projections with walls ~45° off from axis-aligned, it is possible for Mario to move parallel to the referenced wall while still touching its hitbox for 100 units, allowing 400 speed. [TODO images]