So I am installing a full header and all exaust and was wondering if I needed the back pressure tube still as the s5 exaust from RB doesn't have a spot for one as the s4 does.

It is under my impression that the s5 motor doesn't need back pressure for auxiliary ports so I can just toss it right?

Any insight would be appreciated I'm still very new to rotories.

 

You are correct. S5 doesn't use back pressure from the exhaust. It uses pressure from the air pump to open the aux ports.