My son & I did our first autocross of the season this past weekend with mixed results. We made several changes to the ti over the winter which moved us out of HStreet and moved us into STX. Here are a list of the changes:
3.45 Limited Slip
Koni Yellows, all the way round (Fully Adjustable)
H&R Race Springs (2 of the 4 springs that came off the car were broken)
X-Brace
Bimmerworld Camber Shims ( camber is currently at -3.8 degrees)
Previous mods:
Ventus rs-3
Polyurethane front sway bar bushings
The handling of the car is greatly improved. We figure we have gained about 2 seconds over an average 45 second course.
The problems, When really pushing hard, the nasty understeer pops up and the front end washes away. We were running pretty soft on the front struts (about 3/4 turn from softest setting) and a bit stiffer on the rear shocks (1 3/4 turns) Front tire pressures 38psi and rears 41 psi.
We both like the handling & characteristics of the new setup but the car seems to continue to feel and look like it rolls a lot in the corners, and we still need to figure out a way to dial out the rest of the understeer and get the car to rotate more in the corners. I know some of the problem is my driving (I suck) but my son (teen ti) is better and he is having the same problems.
I am thinking we need to stiffen up the rear more and we can still put in a stiffer bar and possibly a shock tower brace. What about wheel spacers to widen the track and some toe out? (we are now without any toe out)
If anyone has any ideas, we would greatly appreciate it.
Here is a link to my sons best run yesterday:
https://www.youtube.com/watch?v=A7UMPP39sI4 
Push, Push, Push 
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