|Removing stock steering rack bushings|
Note that the 2011 STI did get revised, slightly firmer rubber bushings at the front and rear control arms. These Whiteline parts will be firmer still, but the difference from stock on the 2011+ cars will not be as dramatic as on the 2008-10 cars.
|Pointing to the stock rear diff carrier bushings|
Once the car was back on the ground, I took it out on the road to see if I could tell the difference. The effect on the steering was immediate -- between the control arm bushings and the steering rack bushings, it feels like the steering from a different car. There's much more immediacy in the reactions of the front end. Twitch the wheel, and the nose of the car twitches. Go over a ripple in the pavement, and you can feel it in the steering wheel. I love the increase in precision -- I feel like I can place the nose of the car very exactly in a corner.
|Pressing in the Whiteline rear diff bushing inserts|
I can't say there's no effect on comfort from these modifications. The increased feel in the front end is also accompanied by more small bumps and impacts transmitted into the car. The stiffer diff mounting is noticeable when the car goes over expansion strips or other quick, small impacts, and in the form of some additional drivetrain vibration and noise in the rear of the car. (You probably won't notice this from the driver's seat, but rear seat passengers might.) The car isn't uncomfortable to me at all, but it's firmer and not as plush-riding as the OEM bushings were.
Overall I'm quite happy with the changes. The steering feel, in particular, is worlds better than it was before. The whole car just feels more secure and planted because of the more direct connection to the road.