Quote:
Originally Posted by PeterY
....The only two advantages I can think of for this, are more precise steering wheel feel/direction, and the rack will have more leverage to push/pull on the knuckle to turn the wheels, because the mounting point where the force exerted by the rack acts on the knuckle sits further away from the pivot point that the knuckle spins around (strut shock body / steering axis / kingpin angle). There might be other geometry changes associated with the ///M knuckles unknown to us at this stage.
One thing you'll notice as soon as you get into a 1M/M3, their tendency to understeer is a lot lower than non-M cars (even if non-M cars are fitted with top-shelf coilovers, sway bars, same alignment, same camber and same width tyres). Potentially upon compression, the M3 knuckles might be helping with gaining more negative camber?! 
Another thing you'll notice, ///M cars seem to wander significantly less on hard braking, ///M knuckles technically move the front wheels more forwards and change the castor, which reduces front-end/steering wandering under hard braking. |
Just FYI...
Since installing Dinan camber plates to the front suspension of my 135i and installing Bilstein B12, Eibach springs and the rear M3 suspension bits in the rear... I am blown away at how little understeer I have now. Also the rear suspension no longer jumps or has bump steer.
I have still yet to get an alignment bc I have to install the front M3 thrust and control arms soon. To my eye it looks like I am running at least two degrees of negative camber. ? And I also have new HD tie rods to install soon. But I feel that the increased negative camber from the Dinan camber plates, helped enormously to reduce the car's understeer.
Years ago when people first started to install the M3 suspension before the 1M came out... most guys said the rear M3 hubs/knuckles didn't do a whole lot. That's why everyone just installs those four M3 links in the rear. I know on my car just installing those four rear links worked wonders for how my car handles.
Dackel
rear M3 bits... I changed #17 & #18
front M3 suspension... I will install #11 & #6 soon...
rear links non M and ///M bits...
#13 M rear toe link which is too short to use on a non M car.
Dinan front camber plates which add 3/4 of negative camber...
B12 Blisteins and Eibach springs...
Dolomites, Italy...
