B8.0 A4 vs b8.0 S4/5 hydraulic steering rack

[Militant-Grunt]

Has anyone messed around to see if the steering rack in a S4 or S5 is an improvement over the A4 rack? Better ratio / weight / feel?

[Smac770]

It's the same rack. There's three hydraulic racks for the 8K/8T: 1N1 base (8T1422066C), 1N3 Servotronic (8T1422066B), and 1N7 dynamic (8T1422066A). We don't get base 1N1 in the US. Ours are 1N3 normally, 1N7 if you got dynamic steering. The dynamic steering function is mostly in the steering column, but it did also have a different steering rack with a slightly faster ratio. But that 1N7 rack also used a different pump than the 1N1 and 1N3 racks.

As for retrofitting the 1N7 rack in place of a 1N3 rack without bothering with all the steering column stuff and how it played out, I can't recall someone doing it. I would be concerned that the car's ESP would have an incorrect wheel angle assessment based on the steering angle due to the different rack ratio. If you turned on "has dynamic steering", but then the car can't talk to the dynamic steering control module, you'd just have errors going on.