The conventional wisdom I've been hearing on bf.c is that you can get up to about -1.9 or -2.0 degrees per wheel using the stock arms, and that is enough for most track and AutoX drivers. The limit in the front without camber plates is usually somewhere between -0.8 and -1.6 degrees (mine maxed out at about -1.3 per side in front).
Occasionally a hard-core autocrosser running -3.5 degrees in front wants -2.5 in the back, or they want to adjust camber easily for different tires and track conditions, so they get the adjustable rear control arms. If you lower the car a lot, you might need after market control arms to reduce the negative camber.
Last edited by LivesNearCostco; 02-16-2011 at 01:47 AM.