Here is the adjustable ride height "coilover" spring kit I installed on my Rabbit, made by Ground Control, along some parts used to mount it to the A1 strut tubes in conjunction with Bilstein strut inserts. The parts pictured (from left to right) are 1. Eibach 2.5" diameter spring with billet aluminum upper spring perch, 2. Anodized aluminum threaded sleeve and height-adjustable lower spring perch, 3. o-ring for installation in the inside upper groove of the threaded sleeve (to give positive location of the threaded collar to the strut tube), 4. Bilstein insert retaining nut for externally-threaded strut tube, and 5. Bilstein insert retaining nut installation tool. 2.5" springs are available at reasonable cost from a variety of manufacturers in various lengths and spring rates. For my street-driven and autocrossing GTD, I specified a rate stiffer than stock (to stay off the bump stops during hard cornering on sticky racing tires) but didn't specify a lowering spring, since I believe an A1 front suspension, having only roughly 5" from full compression to extension, needs all the suspension travel it can get. Divide that figure by two and it leaves only 2.5" or so of strut compression before bottoming out!

A "clean" installation of the 2.5" springs requires modification to the stock lower spring perches on the strut tubes. Used ones are available inexpensively at a wrecking yard so I decided I might as well do it "right" this way the first time around. At left is the result after the first stage of cutting off the wide stock perch - I set the radial arm saw vertically and using an old insert retaing nut secured to the table, rotated the tube as the radial arm saw buzzed off several large slices of the spring perch. On the right side of the table is the tube after the second stage of cutting. Rotating the blade horizontally and adjusting the height while holding the tube securely against the table, I cut off a clean flat surface for the supplied ground control "weld-on" adaptor to set. The supplied optional "weld-on" ring (sitting below, on table) and slotted tube sit atop the flat-machined surface. Using techniques such as these, one can accomplish the work of a lathe (facing and turning) using a common radial arm saw.

Here is the completed, painted strut tube with "weld-on" support plate installed (right) The other unit (left) shows installation of lower threaded spring perch and Bilstein HD strut insert. Notice the thickness of that shock rod! This denotes the inverted "high pressure monotube," a feature that is offered exclusively for A1s by Bilstein. A note about Bilstein's customer relations - I had a problem getting my original insert retaining nuts off due probably to excessive torque (I'll admit it, the instructions just weren't clear about what "max torque" meant ;) This resulted in a broken installation tool. Anyway a phone call later, two new insert nuts and a new tool were on their way next day air, at no cost! I am seriously impressed with Bilstein's products as well as their customer service. (Did I mention the shocks upon disassembly of the strut worked as good as new?!?) The coating selected for tubes is the only coating I know of that cures quicker the higher the humidity is - the extremely durable POR-15.

Finally, the springs are installed! At right is the strut with "old style" A1 upper strut bearing (an upgrade in service life as well as modularity over the new style "one piece bonded" unit.) Stock rubber bushing is available separately as a replacement part and retains a smooth street ride. At left is the fully assembled strut bearing with AFCO circle-track coilover boot installed (the velcro-fastened flaps allow easy on-car adjustment of the lower spring perch height.)

I installed a rear set of HOR technologie springs (also slightly stiffer than stock GTI) which combined with the front 2.5" adjustables gives nicely balanced handling to the GTD. The rear bilstein HD shocks allow circlip-adjustable ride height so I can dial in my ride height at all four corners now (Which I have kept to the ride height of the car w/ the stock GTI springs.) The end result is great! The reduced body roll increases grip on the autocross course and since it's not bottoming out it's much smoother when it goes over cracks in the pavement at full cornering. The car is also kept flatter on course (pictures on the preceding page were taken of my Rabbit w/ stock GTI springs!)

I waited to upgrade my springs last because I liked the stock GTI springs for their balance of comfort and stiffness for my primarily street-driven car. I chose to upgrade other areas first: Bilstein HD shocks (extremely long-lasting and great balance of comfort and control), Autotech upper stress bar and OEM 16V lower to augment the rigidity of the A1's flimsy front end, polyurethane bushings for the pivot joints in the front A-arms and rear trailing arms (to maintain precise front and rear suspension geometry), and Neuspeed 22mm front swaybar with Autotech 25mm rear.

I am also very pleased with the ride of the new setup - although it is firmer than stock, it is not harsh at all and still very suitable for daily driving on the street. At highway speeds it feels smooth and "planted" + stable too!