Project EP3 Civic Si: Fixing the @$#%! Steering for Good with SHG Motor Works!
Our car had serious steering issues since day one. When we first got our EP3, no one wanted to drive it because the car would wander around on the freeway and everyone was afraid of getting pulled over for drunk driving.
So, we installed a bunch of suspension stuff and finished it with the Hardrace geometry correcting parts in the front suspension. With the car finally handling well, which is no small task with an EP3, we were finally having fun driving it hard. All was good for a couple of weeks, but then the wandering steering returned with a vengeance.
The spirited driving and the increased stress caused by the big Nitto NT05 tires were putting an extra load on the steering rack and causing it to twist. The EP3, along with the DC5 RSX and EM2 Civic, all have a really weird steering rack that has the tie rods attached to a sliding bracket that goes back and forth in the middle of the steering rack.
This bracket requires really long, out of plane tie rods which result with these cars having notorious bump steer issues. The bracket also acts as a lever arm for the tie rods to twist the rack and it moves vertically when it does. When the car hits bumps or in response to heavy tire induced side load, the rack twists, the tie rod ends move and the toe changes with no steering wheel input- ta da bump steer. What makes this worse is when the rack twists, both front tires are effected by the toe change, making things even worse.
When moving our car's steering wheel back and forth and looking at the rack, the vertical play was very obvious after a few weeks of driving with our new suspension. We would have to fix this to cure the issue. When complaining about this issue on our Facebook page, we were contracted by SHG Motor Works who told us they had the cure!