Steering rack

The standard e30 steering rack is a bit on the slow side, 3.9 turns from lock to lock (if I remember correctly), when I fitted the 2.5L engine I also upgraded the rack to one from a e36, which I think was 3.4 turns, the difference was very noticeable, but I still wanted something quicker. I knew the 1.9L Z3 has a rack which is 2.8 turns but these are hard to find and usually very pricey too, so I settled for a E46 clubsport rack which is 3.0 turns but is also supposed to have a better 'heavier' feel than the standard E46 rack. These are much cheaper and very easy to find.
As with fitting the e36 rack there are some modification needed to make it all work. The rack needs spacers to stop it wobbling about in the mounting points of the subframe, these are simple round aluminium spacers, 14mm high, I just had a local machine shop make some up for me.

(Please note the rack should be mounted in the rear holes of the subframe)

Power steering lines - the mounting points aren't in the same place, you can modify (bend) the lines to make them work but I just didn't want to take the risk of it splitting where I'd bent it, especially if it happened on the track, so I decided to get a high pressure line made up for me by Pirtek as they have an outlet not far away. (photo below) I just took in the rack mounted to the subframe with the existing line, and they made that, worked fine and was rated to 3000psi!! But was just a bit ugly.

Ultimately though I wasn't happy with the chunky power steering line and when I saw custom sets being made by a guy on the e30zone I decided to get a set. (photo below is of the E46 rack with the custom power steering lines)

This then requires a 'p' clip to hold the line in place on the subframe, I used my 'rivnut' kit to insert a threaded sleeve into the whole after test fitting and marking the position.

I also upgraded the steering linkage setup. It comprised two E34 UJ's, one of which has been modified to have the top half of the e30 linkage (the part which connects to the steering shaft) and a knurled bar to fit the splines of the two halves together. I 'm hoping I will gain a few extra mm's clearance from the exhaust headers with this (to avoid them locking the steering under hard cornering!!), but I won't know until I fit everything in.

Power steering cooler - Some have said that with this E46 rack and extended periods of high intensity track use that you can boil the fluid and the steering locks!! So I decided to fit a power steering cooler. Some of the e36 racks used to come with a steering cooler mounted to the front of the rack, I happened to have one of these but as there is a possibility I might go off the track on the odd occasion I thought it probably wasn't wise to have it mounted so low without protection (and also right behind the sump I thought it wouldn't get much cooling air) and so I came up wth a plan to mount it behind the front kidney grilles.