Tein FLEX A Coilovers 2015-2021 WRX / STI
FLEX A is equipped with new feature "Hydraulic Bump Stopper (H.B.S.)" which has been tested and proven effective in the world's harshest motorsports including World Rally Championship and European Rally Championship. When a lowered vehicle goes over big bumps, urethane or rubber bump stopper often causes a big upward jolt and/or rebound and can disturb controllability. On FLEX A, H.B.S., mounted inside the shock absorber, effectively generates damping force near and/or at full-bump, to absorb big impact smoothly. Comfortable ride in vehicles even at full occupancy will revolutionize the industry.
Ordinary shock absorbers have to have bump rubbers to avoid damages from bottoming out. Impact from hitting the bump rubber is huge and the energy accumulated by compressed rubber is released as repulsion force, causing unstable behaviors. With H.B.S., such impact is absorbed and converted to thermal energy inside the shock absorber, minimizing the shock and eliminating repulsion force.
Considering the use of larger tires/wheels and the lowered ride height, FLEX A uses twin-tube system, in pursuit of ride comfort on streets.
In order to maintain the ride quality on streets with rough spots here and there, a shock absorber has to have sufficient stroke, be low-frictional and move smoothly.
As an oil chamber and a gas chamber are not arranged serially in a twin-tube system, it is easy to secure enough stroke. Also, low gas pressure keeps friction low.
Its smooth stroke movement makes it possible to follow rough and bumpy road surfaces quite well, offering supple ride at low speed and stable ride at high speed.
Full-length ride height adjustment system, used for FLEX A, enables adjustment of ride height by adjusting the case length, without changing the damper stroke length and/or spring pre-load. This has the advantage that the change in ride quality is kept minimal when the height is adjusted.
This system not only makes it possible to maintain good balance between the low-down appearance and ride comfort, but also provides more setting choices for sport driving as well.
FLEX A has ever-popular 16-level damping force adjustment (comp./rebound together) feature with the use of needle valve. By turning the adjustment knob, damping force (stiffness) is adjusted linearly step by step, to change the ride and handling of the car to suit driver's needs/preferences.
Use of well-reputed "ADVANCE Needle" at the needle valve for oil flow control widens damping force adjustable range to about 200% of the existing lineups.
Whether it's for the handling characteristics of sport driving or for the ride quality according to numbers of passengers, finding the most desirable setting is easier than ever.
With EDFC (Electronic Damping Force Controller) series installed, damping force can be controlled from the cockpit with ease. Stepping motors attached in place of adjustment knobs control the damping force quickly and accurately.
Use of EDFC turns 16-level adjustment into finer 32-level or 64-level adjustment mode (64-level only available with EDFC ACTIVE / EDFC ACTIVE PRO), to provide the optimum performance by fully utilizing the damping force adjustable range drastically widened by the use of "ADVANCE Needle".
With EDFC ACTIVE / EDFC ACTIVE PRO, damping force can be controlled automatically according to changes in G-force and/or vehicle speed, to offer very smooth and slick ride like never before. (Some models are NOT compatible with EDFC series.)
FLEX A kit includes upper mounts exclusively designed for each vehicle model; either reinforced rubber mounts or pillow ball mounts.
Pillow ball upper mounts for front strut suspensions have camber adjustment feature.
(Some vehicle models use OE mounts.)
Full-Length Ride Height Adjustment Feature
Damping Force Adjustment System
Complete Kit with Upper Mount
Ride Height Adjustment with Little or No Change in Ride Quality
For Low Resiliency Securing Sufficient Stroke
16-level Linear Damping Force Adjustment System
Exclusively Designed Upper Mounts are Included (Except Some Models)
Complete Suspension Kit of 4 Shock Absorbers 4 Springs