Tein Flex Z Coilovers for 2015-2021 Subaru WRX STI

Product Description

Incredibly Low Price: FLEX Z inherits all the features and quality of STREET FLEX but the adoption of new platform allows its price to be set at amazingly low range. Top end of shell pipe is drawn, oil & gas are injected then the opening is completely sealed by crimping process. This "Sealed Structure" process also reduces the production time, compared to the production of existing disassembable dampers. In addition, pursuit of efficient production system, such as use of seam welding, allows us to drastically reduce the production cost.

Twin-Tube System for Comfortable Ride on Streets: Considering the use of larger tires/wheels and the lowered ride height, FLEX Z 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 System for Ride Height Adjustment w/ Minimal Change in Ride: Full-length ride height adjustment system, used for FLEX Z, 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.

Damping Force Adjustable to Change Ride to Desired Settings: FLEX Z 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 secures sufficient damping force adjustable range. 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.

Compatible with EDFC Series to enable In-Car Damping Force Adjustment: 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.)

Upper Mounts Included for Easy Installation: FLEX Z 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.)

Highly Durable & Reliable: After many years of research and study, TEIN has developed optimally-shaped dust boot made of most suitable material. Elastic & highly-durable dust boot effectively prevents damages to the piston rod and foreign substances from getting inside the shock absorber. (Some vehicle models use OE dust boots.) Final assembly of shock absorbers is done in the clean room, which is almost equivalent to operating room. Room pressure is kept under control to shut out dust & dirt and all workers entering the room must take air shower, to make sure all the assembly work is done in completely clean air, in order to maintain higher level of accuracy and reliability.

Thoroughgoing Rust-Proofing: Upper mounts and lower brackets are coated with rich TEIN green powder paint. This powder paint has high coating film strength, is highly durable yet is low-pollution due to non-use of harmful solvent. After the shot blasting pre-treatment, the patented "2-layer/1-bake" treatment using anti-rust powder paint is applied for superior durability and high corrosion resistance. (Patent No. 4347712) On shell case, TEIN's self-developed one-of-a-kind "ZT Coating" is applied, for tougher protection against chipping, often caused by bounced pebbles, and rust. With zero claim rate, against adhesion, out of 500,000dampers sold, we are confident that people living in snowfall area or near seashores would even be very satisfied.

Highly-Rigid Bracket & Shell Case: For strut suspensions, sufficiently-thick ribbed plate is used for knuckle bracket to maintain high rigidity. Flange shape edge of the bracket provides larger contact area with the bracket lock, which is fastened with the conical washer inserted in between, to effectively prevent loosening of the bracket lock most commonly occurs on front strut suspensions. Brackets for brake hoses and ABS sensor harnesses etc are exclusively designed for each vehicle model for hassle-free installation. Shell case is made of high-strength steel STKM13C and solidly-constructed for firm handling and stable ride.

Smooth Ride Height Adjustment & One-of-A-Kind Adjusting Wrench: FLEX Z has adopted the new wrought aluminum spring seats and low-friction hard-resin thrust washers. These effectively reduces the friction with springs, caused during ride height adjustment, and makes it easier to adjust the ride height with pre-load on the springs. Shell cases are treated with "ZT Coating", a superlow-friction fluorine resin coating, which is tightly baked onto the surface in-house. This special coating provides superior protection against rust and high lubricity, for keeping a smooth adjustment for a long period. FLEX Z kit includes one-of-a-kind user-friendly ride height adjusting wrench. It has a 12.7mm (1/2in) sq. hole for attaching spinner handle and/or torque wrench for tightening at high torque.

No-Sag Springs: Included springs are made of high-tensile steel SAE9254 (tensile strength 200kgf/mm2 or over) and cold formed for excellent resistance to sagging and for superior quality stability. Surface is powder coated for superb protection against chipping & peeling, for high durability and for superior anti-corrosion performance. High-quality spring can be used under various conditions without any worry. The most suitable shape of spring (straight or barrel-shaped) is determined for each vehicle model, to provide wide ride height adjustable range and to secure sufficient stroke without compromising ride comfort.

High-Spec Damper Oil: Specially-formulated high-spec oil exhibits stable viscosity characteristics at any temperature; from low to high, to allow shock absorbers to stroke smoothly and to generate damping force stably under various conditions. The oil has superior anti-foaming characteristics hence the bubble cavitation and/or thermal degradation hardly occurs, making it even suitable for tough sport driving. The oil also does not deteriorate much with age, making it possible to maintain and deliver superior performance for the long term.

Replacement Service to Bring Used Shock Absorbers Back to Life: TEIN makes NO compromise on after-sales service of FLEX Z. Replacement Service is available for FLEX Z, in the place of overhaul/revalving service, as its "Sealed Structure" components cannot be disassembled.

Brand Information

TEIN offers ideal suspension systems for drivers who want quicker and better response to drive freely through turns and who are in pursuit of ultimate driving experience. It gives your vehicle the road holding which allows you to drive as you always imagined. It is an aggressive suspension which lets you put all you have into driving, and allows you look forward to attacking the next unknown turn. TEIN suspensions maintain their superior performance, and are highly durable. Quality of our products can withstand the high demands of the race track. This is what we see as the ideal sports suspension. Each of TEIN's products brings this ideal to reality.

Our foundation of suspension manufacturing lies on motorsports. We believe that the field of motorsports where each millisecond weighs heavily, is indispensable as a place to improve our suspension engineering technology.TEIN embodies the famous 'Laboratory on Wheels'. Utmost technology comes from the competition fields where winning requires competing for every tenth of a second. All the valuable data obtained from competitions are refind and poured into all TEIN products built for the street.

By applying sealed material to the friction surface, friction is exterminated to the minimum, and smooth movement can be achieved. All of joints are applied with sealed material to ensure stable damping control. We use the highest quality chrome molybdenum, and our rod guide clearance is precise to the 1/1000 mm measurement. The overall capacity of the shock absorbers has been also increased. TEIN shock absorbers are 1.3 times the capacity of normal sports shock absorbers, and we have succeeded in maintaining consistent performance at the most arduous conditions.