Originally Posted by rldzhao
You seem to be correct. ACS does use Sachs shocks, but probably custom springs.
I wonder why SACHS doesn't sell the kit on their own?
I looked into this option prior to going with RD. ACS may have paid for the R&D work, custom manufacturing with some sort of timed exclusivity.
This is similar to what RD did with Bilstein. The Bilstein setup is custom to RD using there design goals and research and test data from the Ring. The setup is exclusive to RD for the M3 application.
The ACS setup is also quite pricey.
However I do believe tuners such as ACS and RD spend quite a bit of time testing there products. They also tend to use OEM suppliers.
I personally believe, as good as the Moton setup is, the RD and ACS setup is a better street / track compromise. That is just part of there design philosophy. It's a philosophy that I feel is more inline with what the M3 is. I believe it's closer to the engineers original M3 vision without having to design and spec for the lowest denominator consumer.
However, with that said, If my main goal was track performance, the Moton setup would be the one to get above the Sachs. It also looks so much nicer.