As thin as you can go without excess clatter or blowing the thing up. This Frees up power and torque, allows it to rev faster.
You will start to notice racket and loss of top end torque as you get too thin. Depending on how you use your engine will determine your thin tolerance level.
You will start to notice racket and loss of top end torque as you get too thin. Depending on how you use your engine will determine your thin tolerance level.