Improving Steering Feel/Tightness/Return

I recently had a friendly debate with a local mechanic regarding what I might do to a still young 2008 Kia Optima to improve the on-center feel/tightness of the steering on it.

I suggested a shop "shimming" an extra 1/2 to 1 degree caster into it, but this guy said no, that won't do anything - you need to adjust the tension/torsion(?) bar at the rack. The rack, he stated, controls steering feel more than anything else on the car.

Who is correct here? And what other things or combination of things could help hone an already decent optima?

Did he use the word "bar" or did you insert that? There may be a pressure valve adjustment or similar fluid path adjustment, but if he said and meant "bar" then I don't know what that might be. I don't guarantee that there is any type of service adjustment on your rack.

You probably could not just "shim" caster in either. I imagine that the front suspension is only adjustable for toe. Most of the economy cars do not have adjustable caster or camber unless you drill out the mounting locations at the strut tower and install an aftermarket kit, but those generally just fix camber issues.

-Rod

Adjusting caster on a FWD car is pretty much non-existent. He is talking about the torsion bar that controls fluid flow in the rack. If the steering wheel is locked, you can feel the tension of that torsion bar if you pay attention, it is springy but not easy to feel. You turn right/left and the bar opens up the appropriate ports. It is non serviceable and you have to disassemble the rack to even get to it. At the opposite end of the rack from where the steering wheel connects is a big screw in plug, roughly the size of a 1/2 dollar. You CAN adjust that but if you don't get it right you will have problems steering/returning/memory steering. You can try tightening it IN VERY small increments, 1/10 of a turn at a time until it feels right to you. Mark the cap and rack beforehand so you can return it to factory if it isn't working out.

Adjusting caster on a FWD car is pretty much non-existent. He is talking about the torsion bar that controls fluid flow in the rack. If the steering wheel is locked, you can feel the tension of that torsion bar if you pay attention, it is springy but not easy to feel. You turn right/left and the bar opens up the appropriate ports. It is non serviceable and you have to disassemble the rack to even get to it. At the opposite end of the rack from where the steering wheel connects is a big screw in plug, roughly the size of a 1/2 dollar. You CAN adjust that but if you don't get it right you will have problems steering/returning/memory steering. You can try tightening it IN VERY small increments, 1/10 of a turn at a time until it feels right to you. Mark the cap and rack beforehand so you can return it to factory if it isn't working out.


What I would rather pursue is intalling a lower-pressure PS system on this car - but that has been disgust(!) here and elsewhere to no conclusion. Who in Rome decreed that economy cars shalt have "soft" steering and/or bountiful PS boost?? At least a "weaker" power assist would allow through more of the alignment's own centering characteristic. 4-5 degrees caster is not a shabby spec for any car, let alone an Asian econobox - it's just that too much PS is hindering its ability to self center or resist the driver's efforts to turn the wheel.

That said, the 08 Optima has a stronger centering force/sense of center "on rails" feel than my '05 Malibu did - even after 2 alignments to that car! Blame that on the EPS!! :D

Bigger pulley, lower ratio rack or fiddle with the bypass.