Dear friends - please advise. I installed damptronic bilstein and decreased the height by -5mm front and -10mm rear (in comp to stock). i am pretty happy with the set up - it just behaves perfect on the highway. Although its pretty tough in the city - and i decided to look into the suspension underneath - i went to the service, jack up the car and realized that the small coil (presumably the soft one) is almost fully squeezed. coming from basic logic i think it does not work properly and that is the reason for the car being too harsh. could you please share your experience and views on the matter - i mean how much the soft coil shall be squeezed and what do you think the reason for the harsh movements in suspension.
thanks!
Vad

 

That is normal...you can get a stiffer helper or tender spring which will help with daily driving...175 front and 250 back range...your best bet is to call Bilstein NA directly for what to do.

 

Yes that is the way they are supposed to be.

 

Normal for helper springs to be fully compressed at static load.

Re. stiffness issue, as mentioned on rennteam, before going anything further, it would help to know what your tire pressures are.
1. Is your car set at "partial load"?
2. When you check the differential pressure reading, does it read +0 at all 4 corners?
Also, I am assuming you are still on original stock tires?

 

Note: if you have different front and rear drops then it changes the nose angle of your car and has a big affect on handling.

I have tried -20mm and currently have -15mm. I still think -15mm is too harsh for bumpy roads, but the car will sag over time (should level off after about 8k miles or so) therefore I plan on re-measuring mine in a few weeks and raising it back to -15mm front and back again. This should allow the dampeners more travel and have a softer ride.

The other thing to watch out for is that your tuner measured the ride heights from the correct locations under the car. Measuring relative drops from fenders is wildly inaccurate.



Here's where mine is currently (CG test3):

 

Normal, don't worry about it.