GP20 -- Thanks for the input. By chance do I have a previous TCK kit you've owned? I bought mine from Haretakis and he had mentioned that he bought it from someone on here and I think he may have said it was you. Roads are pretty terrible here too in Boston (and Manhattan, duh) where I do tend to drive a good amount. I think the 400lb springs will be what I start with at the track and, depending on how it meshes with my style on the track, I'll consider the 500lb springs I have as well and take it from there. Springs are so easy to change on coilovers that I don't mind the project if I decide to make change.
silversprint -- So, about my alignment specifications, I understand exactly what you're saying. I didn't really think through the order of operations I'd go through when having it aligned so I had them put it to street settings and be done with it. When the season rolls around I'm going to have the car re-aligned. I will be using nifty custom front strut mount reinforcement plates that will, among other things (like reinforce the mount points of the stock diagonal braces), get rid of the frustrating stock camber adjustment slots and make them just holes. I'll align it first to track settings (-2.5 to -3.0 camber; <.01 toe-in) and mark the plates. Then, we'll go to a more reasonable street camber (-1.25 to -1.75) and check the toe. It'll increase toe-in, I know, but I'm hoping it stays within factory spec (<.13). If it doesn't, we'll play with it. I bought one of those Craftman zero-able levels at Sears that will allow me to confirm at the track that I'm at a particular camber setting that I know the toe value for. Any input on how much of a change in toe I can expect between, say, -2.5 and -1.75? Just curious.
How can I call a 3400lb car darty? Easy. It's a shorter wheelbase car with the same engine as the E46 M3 and I'm coming from a sublimely balanced (albeit comparatively underpowered) 330Ci. Hence, in my worldview, it's darty. And having spent quite a number of days at the track this past season with many Z4MC owners, they all agree that it is one of the more "busy" driving experiences than other BMW's out there.
Now, that said, I understand you're trying to help (and you have been!) but you should watch your tone a bit. It's coming off as condescending. I apologize if that isn't your intention but that's how I'm reading your comments.
