Stock Airbox


New member
Need some help. When using the stock airbox, do you plug the hole and remove the tube going to the valve cover, or leave it as is and not run a catch can?
Some tracks require a catch can regardless. What does your track require? If not, you should be able to leave it be.
The tube from the valve cover to the air box is a pollution control measure. A performance engine should not have the crankcase gasses fed back through the intake. The reason the tube is there is to reburn any gasses emitted from the crankcase rather than have them expelled to the environment. The gasses emitted should not have anything in them that would enhance your combustion, get rid of it..