DosQuattros

Car is an '03 A4. The OE non-sport springs/shocks were replaced with Eibach Pro-kit springs and Koni sport shocks in mid '05 at 27k miles.
Since new, 90% of the miles have been on smooth highways, and the car now has 57k total.

For a number of reasons (example, increased travel on rutted dirt roads, where ride quality and ground clearance is an issue) I'm considering re-installing the OE parts.

1) the OE shocks have been stored in the extended / non-compressed state. Does this do any harm, or can they be re-installed without issue?

2) if the OE shocks should not be re-used, are the Koni sport shocks compatible with the OE non-sport springs? The ride height is ~ 1.2" different between springs. I'm aware non-sport shocks w/ sport springs is ill-advised.

Any other related input (of value) based on experience, etc. is appreciated. TIA.

EBG 18T [Eric]

1. shocks will be fine. 2. Koni sports are fine with the OEM springs.

Just Me

Agree the OE shocks will be OK after storage.

Sport shocks have a shorter piston travel. This leads to 2 problems, potentially. 1) they can bottom out since the suspension now travels more than they were designed to accommodate. 2) In steady state running, the shock will be "off center". If the shock is designed to vary its damping with increased excursion, this impacts damping.

in addition, the damping will be much firmer than required for the OE springs. Might be over-damped, and certainly will contribute to a continued rough ride, without the benefits of stiffer springs.

Grant

EBG 18T [Eric]

with OEM, OEM sport and aftermarket springs that do NOT lower more than 40mm. Lowering more than 40mm is out of the range of the Koni Sport damper. Koni also claims the ajustment range on the Koni sport damper will go from OEM to a compression/rebound rate able to cover OEM +50% spring rate at the MAX.

IMHO running OEM +50% spring rate is out of the operating range of a non-modified damper. But also depending on how stiff the shocks are adjusted you will find the shock dyno curve fairly linear. Actually it was more linear that OEM Sport which would result in a slightly better ride quality.

But once adjusted to higher dampening ranges it was definitly less linear. Seeing as many OEM and aftermarket springs are progressive this non-linear range works very well with those springs.

With that being said most people are setting up their cars to look good and may not have your experience with suspension tuning.

You points are valid in all cases, but with the dampener that was mentioned, the manufatuer claims it is ok.