[GreasyGinzo]

I was looking around for what exactly the comp pack gave you and saw mention of a tighter ratio steering rack. Is this true? If so anybody who has driven both (ZCP and non-ZCP) can you comment on how much of a difference it is? I would imagine its like the difference between "Normal" and "Sport" Servotronic modes on MDrive equipped e9x M3s?

[M3SQRD]

Originally Posted by GreasyGinzo

I was looking around for what exactly the comp pack gave you and saw mention of a tighter ratio steering rack. Is this true? If so anybody who has driven both (ZCP and non-ZCP) can you comment on how much of a difference it is? I would imagine its like the difference between "Normal" and "Sport" Servotronic modes on MDrive equipped e9x M3s?

I believe the zcp cars came with a 14.5:1 rack compared to the standard 15.4:1 rack so the zcp rack is a bit quicker. I have a '03 e46 M3 but I've never driven an e46 M3 zcp but I was told not to perform the steering rack swap by someone that professionally races BMWs - basically no performance gain once you've become familiar with a given rack (i.e., response for a given steering input).

No, it's not like the different setting on the e92 steering rack which changes the amount of power assist. The e46 M3 zcp rack requires only 14.5 degrees of steering wheel rotation to turn the front wheels 1 degree whereas the non-zcp requires 15.4 degrees of steering input to turn the wheels 1 degree. It has nothing to do with the amount of power steering assist.

[M3Bahn]

I bought the ZCP because of the rack and steering feel, others say they can't feel any difference.

[KnowControlE46]

Originally Posted by GreasyGinzo

I was looking around for what exactly the comp pack gave you and saw mention of a tighter ratio steering rack. Is this true? If so anybody who has driven both (ZCP and non-ZCP) can you comment on how much of a difference it is? I would imagine its like the difference between "Normal" and "Sport" Servotronic modes on MDrive equipped e9x M3s?

Yes the ZCP has a tighter rack, as it was mentioned before. ZCP is 14.5:1 and normal is 15.4:1, and while the ZCP rack is tighter it isn't very noticeable. I know because I have driven both.The only rack swap I've heard of having a huge margin of change is swapping in a Z4M rack which I believe is a 12.8:1. Somebody on M3forum.net did it I believe. I read about it a long time ago.