Our DSD suspension is a result of over three years of track and street testing to provide a complete coilover system that would allow tight yet cushioned ride, but would be able to handle a weekend in the canyons or on track. It’s full-length adjustment system keep ride height and preload adjustments separate by having easily adjustable length shock bodies. This feature allows you to make quick setup changes with the included forged spanner and also allows corner weighting without affecting spring preload. Damping curves are easily adjusted through the top of the shock. We use 8/5 settings for the street and start at 15/12 for track. Our testing was done using BP and V8 conversion cars. Spanning over 40k miles and dozens of track days through the course of testing. For larger wheel and tire combos and more dedicated track uses we recommend 12K front and 7K rear spring rates. For touring street use and occasional track 8k front/ 5K rear. NA/B 1990-2005: Fully threaded aluminum bodied Mono-tube design 30 way adjustable valving, rebound and compression together Independent pre-load and ride height adjustments 10K(560lbs) front 7K(392lbs) rear spring rates standard. SAE9254 high strength cold wound then heat treated steel springs Aluminum upper mounts, rubber isolated to help aid NHV NOK oil seals, 20w race series oil Bump stops and dust boots included Hard anodized for corrosion resistance Shocks can be rebuilt or custom valved Supported by a 18 month warranty Coilover are assembled with your choice of rates. Please allow a few days for assembly before shipping.