Tuning help

[davidkillion]

The car is a 1998 318ti with Bilstein PSS9 coilovers. The spring perches have been removed from the back and the coilover height in the front has been set for only a mild rake to the front (it is pretty darned low). I have changed out the control arms, ball joints and tie rod ends to tighten up the front end. I also run EBC Green Stuff brake pads on EBC sport rotors. I run the stock sway bars and no X brace. I autocross it at full stiff on the front and back shocks.

When I originally autocrossed it with 480 treadwear tires it was quite fun and most of my understeer issues could be resolved with some agressive throttle to bring the rear end around.

I decided to change tires and everything has been downhill since. I went from a 205/60-15 Bridgestone (480 treadwear) to a 225/50-15 Yokohama ES100 (240 treadwear).

So here is the problem. The overall grip is better, but the dreaded understeer still exists. I'm talking PLOWING! The worst part is that with the added traction in the rear, the little 1.9L engine cannot break the rear tires loose. At this weekend's GGC BMWCCA autocross I struggled in all 7 runs to plant the front end under braking and get the car steered and it feels like I had to come to a stop to get it to rotate. The bottom line is that I think I was faster with hard tires because I could "drive" the car ... not let it drive me.

Below is a picture of the car on Laguna Seca with the 480 treadwear tires coming out of turn 5 ... it shows the lean of the car at current state.

What should I do? The options for stiffening up the front are the X brace, stiffer sway bar and shock tower brace, right? Of these three - which will be the most effective at solving this understeer issue? Are there other tuning tips for dialing out the understeer in this car?