Hey jbh, congrats on the new purchase. I just autox'd mine today for the first time, had a blast, but yes a lot of understeer. Here is a paragraph finnegan email me a few days ago. there is a great link in there that talks about tire set up, etc.
Hopefully this will be a good jumping off point for you:
this is the link to the thread mentioned below:
http://www.zpost.com/forums/showthread.php?t=367909
Have you seen our "dead tires thread"?It's a pretty good primer on our journeyaround tires, alignment, understeer, etc. The stock setup of the car is way too oriented to understeer due to insufficient front end negative camber. Max you can go, with the pins pulled, is about -1.0. Then it's camber plates or some E36 washer/bolt combos that can dial in more in .5 degree increments. Have the washers on order from Turner (want about -1.5% to balance the -2.0 in the rear), and the CDV (clutch delay valve) delete on the way from Zechausen Racing. (Car, used, had +.01 on the passenger front, damn it sucked at speed....) Hate that CDV--makes me look like I can't drive stick worth a damn every now and then.