hi
i have one of the above on my type r and today whilst cleaning the engine i noticed that it has two arrows one direction is hard and the other is soft.
what does this do ? will it do any damage or affect how the car runs if i change it?
thanks

 

if you turn it the hard way, it will compress the spring inside the valve therefore requiring a greater pressure to dump the air. Opposite happens if you turn it the soft way.