OK so have an 2004 RX8, I have installed a SON adapter on the firewall , replaced washer fluid basket with two smaller units. I have read about catch cans and I'm wondering if I can just route the blow by tube from the air intake to the Filler Can for the SON adapter or do I need to install another "can". and second would I need an air breather on it or just allow the oil filler on the SON adapter to vent?

 

You probably could but I'm not sure it's easier than just running another can.
Basically the oil reservoir should be vented, so consuming oil doesn't create a vacuum. I guess you could run the PCV line to it, and then to the intake, but the intake end is under vacuum, and you don't want it sucking up your 2 stroke oil. So, if you do this, make sure there is proper PCV air separation and that oil can't enter the intake side.

Do you need a catch can at all?

 

you should have neither, but newbs gotta newb ...

 

Thanks, I have a blow by problem into the air intake and thought I could re-cycle the blow by oil in the catch can.

 

Watch a video where someone empties their catch can. Do you want to clog the oil injectors with that crap?