well i am going to be doing the K&N cone filter on the mafs, could someone enlighten me on the size of opening on the S5's mafs so i could buy this filter with out taking the mafs apart twice...

 

First it's an Air Flow Meter; hot wire mass air flow sensors weren't on our cars or used until pretty much the mid 90s.

I did a quick search of "afm diameter"
https://www.rx7club.com/showthread.p...t=afm+diameter
it appears to be 2.5", I used a 3" hose clamp on mine, so that's it, 2.5".

And you're really complaining about the work to take off the complete 6 or so bolts to get the stock air box disconnected? I hope that you realize that a cone filter will hurt your performance unless you take the time and effort to build your own cold air box.