Originally Posted by
Speedychris22
when your talking about the 521 arms, u mean 521-1 not reg 521 right?
The only difference between them is the shock hole, the 521 has inside/outside, and the 521-1 is the middle of those two.
My car was really good in 17.5 with the rb6 arms/MM but could be a bit more free, going to swap arms this week and see if I can feel or see it in the lap times.