Bye-bye Bump Steer!
When I first purchased my 240SX, the handling was terrible. The car was "slammed" on coil overs. Although the car looked good low, the appropriate supporting mods were not performed to ensure the car maintained good alignment and handling. When I got the car up on a lift, it became immediately apparent why the steering wheel was shaking back and forth in my hands every time it hit a bump - bad bump steer caused by excessive angle of the lower suspension arms and the tie rods. Instead of being angled upward, the lower arm and tie rod should be parallel with the ground. Thankfully, the aftermarket has a solution for this problem.
The first thing I ordered was a set of drop spindles from GK Tech. These spindles raise the position of the axle up an inch and a half to restore the proper angle of the lower suspension arm. They are available in both "grip" and "drift" geometries. Because this is a street car, I chose the "grip" version.
After installing the drop spindles, I was happy with the angle of the lower arms in front. However, I noticed that the stock tie rod was still not parallel with the ground. In order to rid all trace of bump steer, it would be necessary to install aftermarket tie rods as well. Back to the GK Tech catalog!
These adjustable tie rods offer a stackable spacer arrangement that allows the arm to be lowered to be more parallel with the ground. They also feature heavy duty rod ends with rubber dust boots, and beefier 14mm threaded rod construction. These items are cut to fit and must be modified to fit the car they are installed on.
After some careful measuring, the inner threaded rods were cut to the appropriate length. It was also necessary to cut down the tapered shaft that the rod end mounts to. With the included spacers, these rod ends were able to be mounted 15mm lower than the OEM tie rods.
Here, you can see the protective rubber boot installed over the rod end. Note that clearance between the lock nut and the barrel of the wheel is very close. It was necessary to bring the tie rod as low as possible without hitting the wheel to get the rod parallel with the ground.
Here, you can see how the tie rod is almost level with the ground. It is impossible to move the tie rod any lower without hitting the wheel. Case closed!
After installation of the tie rods, I took the car for a professional alignment at P&L Motorsports in Lisle. My garage alignment was actually very close to OEM specs. The ride home was sublime - rock steady, no bump steer, planted and GRIPPY. After all this work, I look forward to putting a lot more miles on this car this summer. Finally, I can drive this car on the limit without fear of scraping, bottoming out, or strange steering feedback. Getting a car to be low and handle correctly takes a lot of time, effort and money. There are no shortcuts.