When I bought Tein Flex (www.tein.com) for my VR4 a few years ago, I bought the EDFC as well. In fact, I made a conscious decision to go with Teins instead of JIC coilovers (which is the best mainstream suspension on the market) because I thought the easy adjustability would be handy in a street/track car.

At first, I used the EDFC quite a bit. I would use different settings for highway, rough roads, and city driving, and I would fiddle with the settings while driving. But, after a few weeks, I found that the affect of the EDFC was mostly psychological. I found one dampener setting that worked very well and started to use it for everything. (Remember that the range of useful dampener adjustment is significantly less than the full range available, because the spring stiffness is going to render a large portion of the full range useless.) I even found this setting (8 in the front, 6 in the rear, for you Flex owners who want to know) to be favorable for track use. I haven’t changed the dampening or used the EDFC since.

The EDFC motors also have some quality issues. The shaft of one of the stepper motors began to bind after about 6 months, and another one of my stepper motors broke in two: The threaded ring with which you attach the stepper to the head of the strut body sheared off from the body of the motor itself. Replacements are expensive (70 dollars or so).

It certainly is a fun little gadget, and the screen, buttons, and noises make you feel like you’re driving the Batmobile. But Tein’s EDFC has minimal practical value. If I had it to do over again, I wouldn’t spend the money.