Hey, i'm Ivano from Scotland.. I have just signed up and thought that i would report that i also had the problem of vibrations after lowering. I orginally lowered my MINI 2" on KW Variant 1 Coilovers ( SEE PIC) and the car suffered from the problem. I have since raised the car back up to 1" drop and the vibrations have all but gone which i'm delighted with.

The other problem i have encountered is very similar to a recent post about M7 Coilovers and GP Wheels with the wheel hitting the Coilover. My KW Coilovers were hitting my JCW 18" alloys and scraped the inside edge of the wheel. i have since fitted 5mm Eibach Spacers on the front and i now have enough clearance that the wheel no longer hits.... It must be something to do with the offset of the OEM JCW alloys

 

sorry....I had beans for lunch

 

The factory has additional parts that are needed when fitting the 18" JCW wheels to eliminate rubbing (I think it was bracket to limit steering angle)

The other issue is that by lowering so much you might be hitting your bump-stops, you've increased your spring rate, or most likely, you've changed the suspension geometry... as you noted that the vibration is gone by raising the car an 1"

There are a lot of threads, some very technical on this last point...
HTH.

 

they do but this doesn't affect the wheels hitting the coilover when the wheel is straight. It seems that the JCW wheels are so far inboard that they tuck under the stock perch. Coilovers normally give more clearance for wider wheels and tires, but the body is generally uniform and smaller throughout vs. the stock setup. A high offset puts the wheel closer to the coilover body....I'm a bit surprised 18" JCW wheels have more offset than 17" OEM.

 

Yeah i do have the steering bracket fitted due to the JCW Alloys.... but i'm just pleased that i don't have anymore problems....... The KW Variant 1 Coilovers give a comfortable ride in my opinion especially when some of the Scottish roads are Pothole Central...........