The Eibach ERS 12.00 in. length x 3.00 in. ID coil-over spring is a main race spring from Eibach's ERS race spring line, built for coilover shocks that need a 12-inch free length and a 3-inch inside diameter. Eibach's race spring system is designed around combining main, tender, and helper springs, so a tuner can set the rate curve for a specific track setup. A buyer choosing this over a stock coil or a generic coilover spring gets a rate that can be adjusted through spring combinations rather than replacing the entire coilover body. Search terms like "Eibach ERS 12 inch coilover main spring," "3 inch ID race coilover spring," and "Eibach ERS spring rate track setup" describe this part's use well. Confirm the rate for your exact part number before ordering, since the rate is not listed here.
Fitment depends on the coilover body, not the vehicle alone, so match the 3.00 in. inside diameter and the 12.00 in. free length against your shock's spring perch and available travel before buying. Eibach's guidance is to measure ride height before and after the change, and to mark left and right parts and the alignment-related bolts before removal. The manufacturer also specifies that all original tubing and isolators should be reused, that the spring should be installed with the Eibach logo facing up, and that a post-install wheel alignment is required. Use a proper spring compressor, because the manufacturer warns that these springs store a large amount of energy.
The manufacturer states that all Eibach springs are designed for use with new isolator pads, and that worn pads must be replaced before installation. The manufacturer also says the original isolators and dampers should be kept from the stock springs.
The manufacturer recommends leaving a quarter inch to a half inch between the end of the coil and the spring seat pocket. The manufacturer says this gap helps prevent spring noise when the suspension meets large bumps.
Yes. The manufacturer says to preload the suspension before tightening the pivot point bolts, which the manufacturer states leads to more consistent lowering and longer life for the pivot bushings.
Coil-over spring swaps are a intermediate-to-advanced DIY job because the spring must be compressed safely before it can be removed or installed. Eibach's install sheets recommend a hoist and a screw jack to make the work easier, and a spring compressor is required. Before disassembly, measure your ride height, mark the alignment bolts and left/right parts, and note where brake lines, ABS wiring, and other lines are routed, since the manufacturer warns that reinstalling lines in a different position can cause damage or brake failure. After installation, check wheel alignment, tire clearance (especially with aftermarket wheels), brake line clearance, and ABS sensor positioning.
