I have a pair of nice S5 N/A rotors that I'm using in a motor for my car, now I'm kinda peicing the motor together with a bunch of random parts I have kickin around the shop.

Most of the engines I build use all the same peripheral stuff from the same motor, so I dont really know what I'm doing once I start trying to match up counterweights.

One place told me that if I use the S4 front and rear auto counterweight with the S5 rotors, it'll be fine.......

Another place told me that if I use an S5 front counterweight and the S4 rear auto weight, it'll also be fine.....

WTF do I do?

BTW I'm using a lightweight Tweakit flywheel so thats why I need the rear auto counterweight.

 

I would say just try to keep everything within the same series

 

yah you need to use s5-fd counterweights with s5 rotors. s4 would need rebalancing

 

if you use S5 rotors, you need to use S5 counterweights.
S4 rotors need S4 counterweights.