to redirect the exhaust flow from the original flow to shorter exhaust flow.
So , like using straight piping without muffler la after the valve open coz the air will go through the new hole.
Hi guys, my e9 when i shift from 1st gear to 2nd gear i have to push harder to get the gear in, and its not smooth like other gear,someting like krik krok then gear in, and only hapend to 2nd gear,other gear no...