I am going to be using a PowerFC on my S5 turbo vert project and was wondering which one I needed? I know there are 2 different versions for the FD...Which one do I need? How can you tell by the serial number which is the right one?

 

APEXi Power FC (Part # 414AZ004)
That's according to Banzai Racing. It's the same for both the S4 and the S5.

 

how can i tell by the serial number?

 

The serial number on the Power FC ? That I'm not sure of. Probably have to call Apexi and ask them which one the two part numbers your serial number is for. Is that what you're getting at ?

 

http://www.clubrx.org/media/pfc/PowerFC_FAQ.pdf
section 2b has a read up about the s/n.
pg 15 has the second gen write up for the pfc by DaleClark