by Robert Bowen
(Taken from BMW 3-Series (E30) Performance Guide 1982-1994 by Robert Bowen)
Vorshlag Motorsports was kind enough to help in this installation of AST coil-overs in an E30.
Here is a comparison of the AST adjustable shocks and spherical bearing mounts (top) and the stock rear shocks and rubber upper mounts (bottom).
1. You don’t have to remove the factory strut housings to install most brands of coil-overs. Just get rid of the stock upper mounts, springs, and insert retaining nut.
2. This is what the factory and AST strut inserts look like. The factory one is red and does not have gas-charged internals. This is a factory-length strut, but most coil-over kits actually use a shortened strut to maximize front suspension travel.
3. Once the nut is removed the factory insert can be taken out the top.
4. Pull the factory insert up through the original strut-mounting hole in the tower.
5. Drop the new insert into the housing where the original came out of.
6. Each coil-over manufacturer has a different lower retaining nut/perch design. These AST coil-overs have a combined retaining nut and perch that replaces the factory nut.
7. Slide the new coil-over spring (in your preferred rate) to the coil-over’s lower perch.
8. Install the new upper perch onto the spring and prepare it for installing the upper strut mount.
9. Install the upper strut mount according to the instructions; in most cases simply by bolting it to the strut tower and tightening the strut mounting nut. Head to your favorite alignment shop to have the car aligned the way you want.
10. All E30 coil-overs maintain separate springs and shocks in the rear with a threaded adapter for the rear springs. This allows you to raise and lower the rear of the car (and adjust corner weights). (Photo Courtesy Vorshlag Motorsports)