Contour Enthusiasts Group Archives Forums Modifications Suspension Vibration problem

ok, heres the deal. i lowered my 99 SVT about two weeks ago with Konis and Eibachs. at the same time, i added 18" Enkie Rs-5s and Nitto 215/40/18s. as the car passes 40mph it seems to pick up a slight vibration/shimmy that i think is coming from the front. the vibration/shimmy gets progressively worse as speed increases. i have to travel the interstate every morning going to class and by 70mph its pretty bad. i took the car today to get it balanced and aligned to see if that would help. but the shop just called me and told me they couldnt find the problem. does anyone have any ideas about what could be wrong or where i need to go from here to solve it?

Allignment shouldn't have been your problem but it sounds like a wheel problem.. Don't personally know your wheel type but they may need wheel-centric spacers to snug them up to the axel.. sometimes the wheel manufacturer fails to suppy them or sends the wrong size.. When mounting your wheels, you should snug the wheel lug torque a second time after 20/40 miles of driving..