Nefarious Racing

TEIN Flex Z Coilovers

The Flex Z are TEIN coilovers designed for performance driving while giving you a comfortable street ride and have all the features you would expect from a proper coilover kit.

The TEIN Flex Z’s are manufactured and assembled in Yokohama, Japan, at TEIN’s manufacturing facility, making them a true JDM coilover.

They feature 16-level dampening adjustment, which gives you the ability to really get your ride quality set the way you like it. The dampening adjustment is done with either the supplied tool or an Allen key at the top of the shock, by turning it clockwise or anticlockwise to go soft or hard.

TEIN Street Advance Z Coilover Dampening Adjustment Diagram

They also allow you to independently adjust the ride height from the spring, by adjusting the shock body rather than winding the spring up and down.

This allows you to set the spring preload and get full travel from the shock no matter what ride height you are running at. This not only makes for a better ride and more control, as well as allows you to fine tune the ride, but also makes the dampers last longer too.

As they have adjustable dampening, they are also compatible with TEIN’s EDFC System (Electronic Damping Force Controller) while allows you to adjust the damper settings while driving from inside the car (purchased as a separate unit).

The springs on the Flex Z’s are typically a bit stiffer than on the TEIN Street Advance Z’s and come in the standard 2.5” ID, meaning that it’s easy to get replacement springs in different spring rates if you want to change them.

The Flex Z’s come with either pillow-ball mounts which allow camber adjustment, or reinforced rubber mounts.

While the shocks are non-rebuildable, you can buy replacement dampers for them from TEIN, which TEIN will custom valve to your specifications if you wish.

So if you blow a shock, you can simply get a replacement and swap it in, no need to wait for a rebuild and have your car out of commission.

Here are the features of the Flex Z’s:

TEIN Flex Z Features:

TEIN Flex Z Coilovers
  • Ride height adjustable up to 5 inches (125mm) lower than stock (depending on vehicle model), which is done at the shock body, independent of the springs and allows you to set the spring pre-load and get full suspension travel at all ride heights
  • 16-level adjustable dampening
  • Compatible with TEIN’s EDFC system which allows you to adjust dampening from inside the car while driving (sold seperately)
  • The springs are cold formed from SAE9254 steel (with a tensile strength of 200 kgf/mm2 minimum) which ensures they won’t sag and have an extremely high resiliency
  • Twin tube damper design which, compared to a mono-tube shock, has a longer stroke and a smaller repulsive force, resulting in a much improved ride quality
  • Use TEIN’s special damper oil which has proven to have a stable viscosity in a wide range of temperatures, meaning that it will sustain a smooth stroke and reliable damping force no matter the circumstances. The oil is also extremely resistance to deteriorating over time.


    Because of the damper oil’s excellent anti-foaming qualities, resistance to cavitation (bubbling) and its ability to withstand high temperature ranges, TEIN dampers are suitable for performance driving as well as street use.

  • TEIN’s famous green powder paint which is used on the shock body is no ordinary power coat. It’s actually patented by TEIN (Japanese patent number 4347712) for its 2-Layer, 1-Bake process, which contains 2 layers of anti-rust coating for maximum protection.


    This creates an extremely durable barrier against corrosion and rust which makes the suspension suitable for use in any weather condition including snow and coastal areas which usually mean high chance of rust.

  • The adjustment threads on the shock body are protected by TEIN’s unique ZT Surface Treatment Coating which is extremely resistant to abrasion from gravel and other debris and adds further corrosion resistance, which means your adjustment collars will never get seized.


    TEIN has never had a single claim due to stuck or seized parts with over 500,000 coilover kits sold, which proves they are extremely rust proof even in snowy regions and coast areas.

Are TEIN Flex Z Coilovers Good?

Yes, TEIN Flex Z coilovers are very good, especially for the price. Some people even compare them to KW levels of quality. We actually covered this in our blog post Are TEIN Coilovers Any Good? so if you want to know the details go check that out.

How Low Do TEIN Flex Z Coilovers Go?

TEIN Flex Z coilovers will lower your car by up to 5 inches (125mm), depending on the vehicle model.

Is TEIN Flex Z Serviceable?

TEIN Flex Z coilovers are not serviceable but you can buy replacement shocks from TEIN which you can swap out, so you don’t have to buy a whole new coilover kit.

Can TEIN Flex Z Coilovers Be Rebuilt?

No, TEIN Flex Z coilovers cannot be rebuilt, however you can buy new replacement shocks from TEIN which you can swap in, which is actually faster than rebuilding them. TEIN will also custom valve the replacement shocks for you if you want them to.

How Long Do TEIN Flex Z Coilovers Last?

People have reported that the TEIN Flex Z coilovers last a really long time, and are super durable, meaning you won’t need to replace the coilovers any time soon. And if you do, you can buy replacement shocks from TEIN, meaning you won’t have to buy an entire set of new coilovers.

How Do You Adjust TEIN Flex Z Coilovers Stiffness?

You adjust TEIN Flex Z coilover stiffness by either adjusting the spring pre-load or by turning the dampening adjustment on the top of the shock with the supplied tool or an Allen key. You can also get the TEIN EDFC system which will allow you to adjust the dampening from inside the car, even while driving.

How Do You Adjust the Height On TEIN Flex Z Coilovers?

You adjust the height on TEIN Flex Z coilovers by winding the shock body up and down, not the spring. This allows you to set spring pre-load and get full shock travel at any ride height.

Are TEIN Flex Z Made in Japan?

Yes, TEIN Flex Z coilovers are made in TEIN’s manufacturing plant in Yohokama, Japan.

Not Sure Which TEIN Coilovers Are Best For Your Car?

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