Engineered and manufactured by Swift Springs, these are designed to increase performance while keeping an OE like ride. Designed around the useable stroke of the suspension, allowing you to lower the vehicle without decreasing the life of the factory dampers. OEM CT4-V Blackwing spring rates are 179 pounds/inch for the front and 590 for the rear. Swift Sport CT4-V Blackwing spring rates are 215 pounds/inch for the front and 680 pounds/inch for the rear with a target drop of 20 mm. First production set actual drop measurements were 17.5 mm. (front) and 20.6 mm. (rear).
Sold as a set of four springs. You should have your alignment touched up after installation.
Will these lowering springs fit CT4 or CT4-V, non Blackwing cars?
We’re not sure, since we have never tried them. Our guess is that they’ll fit the car, but the 20 mm. target drop will likely be slightly different.