HKS Hipermax IV GT SPEC20 Coilover Kit - Toyota Yaris GR





  • Made in Japan by HKS Supreme Quality
  • 30 Step Adjustable Damping Force Front & Rear
  • Upgraded Rear Rubber Mount Inserts
  • Fully Height Adjustable 0-45mm Front and 0-47mm Rear
  • Spring Rate Front 69Nm and Rear 59Nm
  • Damping Rebound Force (N*) Front 603/490 and Rear 363/452



There is no secret that parts made in Japan are beyond any technological advancement of the western-world and also a superb build quality.


Whether it is engine, exhaust, suspension, or drive-train systems, there is no substitute for the performance, quality and reliability of HKS. Pumaspeed are an approved distributor for HKS performance and tuning products. For over 35 years, HKS products have been put to the test in drag racing, road racing, rallying, and top speed trials. HKS equipped vehicles have captured numerous racing championships and hold claim to a myriad of competition records using many “off the shelf”, race proven HKS components. As a result, HKS has been synonymous with “performance” in the automotive aftermarket industry for the past 35+ years.

Developed and tested by the HKS racing team in Japan and fitted to their own track car. Improve the handling and performance of your GR Yaris whilst simultaneously bettering the ride height and overall look of the car. Many customers that have driven/seen the HKS GR Yaris are amazed at the transformation this simple bolt on kit has made to the handling. Comments such as  ' Smooth',  'Effortless', 'Precise'  have been very common on the Facebook forums. 

Fully height and damping adjustable both front and rear... this is the absolute essential kit for those serious about driving their GR. 




Engine G16E-GTS
Model Year 20/09 - 
Remarks Developed in RZ High performance 1st edition


Damping force adjustment 30 steps 30 steps
Base valve - -
Height adjustable lower bracket
Upper mount Stock Rubber
Inverted/Normal type Inverted Normal
Damper/Spring layout Coilover Separated
Spring rate change at factory Possible Possible
Damping force adjustment with wire - -
Helper spring
(Spring rate N/mm)
- -

Ride Heightmm

  Factory *2 Test data Adjustable range
High - Low *3
Drivable range
High - Low *4
FRONT Ride height *1 654 679 ~ 634 679 ~ 634
Against stock -25 0 ~ -45 0 ~ -45
REAR Ride height *1 651 677 ~ 630 677 ~ 630
Against stock -26 0 ~ -47 0 ~ -47


*1. Height from road surface to fender arch.
*2. Height at factory is the data tested at HKS with the setting of Full Kit. (HKS' recommended setting.)
*3. Adjustable range (However, the lowest value may not be road legal.
Even within the adjustable range, car body, arm etc. may contact. In such case, it will be hard to drive.
Damper oil leakage or any other problems caused by low ride height setting from the factory setting will void the warranty of the product.)
*4. Drivable range that there is no contact of car body or arms etc. (However, change of tire/wheel size may cause a problem.)
Caution). Actual data depends on each vehicle.


Kit information

Spring of Full Kit

  F R
Spring rate N/mm(kgf/mm) 69 ( 7.0 ) 59 ( 6.0 )
Free height (mm) 200 250
Spring type Straight Barrel type Straight Barrel type
Recommended range to change spring rate N/mm(kgf/mm) +10 ( 1 ) ※5 +10 ( 1 ) ※5

Specification of damper

  F R
Damping force (Rebound/Damping)N* 603 / 490 363 / 452
Default position of dial 15 15
Remaining damper stroke (Rebound/Damping)mm 45 / 61 49 / 65

* The value of the damping force is at piston speed of 0.1m/sec.

Setting data

  F R
Default Test Drivable limit
High *
Drivable limit
Low *
Default Test Drivable limit
High *
Drivable limit
Low *
Length of
case (mm)
301 326 281 273 290 255
Set length(mm)
203 203 203 - - - -
Length to ride hight
adjuster (mm)
20 45 0 40 58 25
Lever ratio 1.02 1.42(spg) , 1.32(dmp)

* Refer to the above explanation *3 of ride height information for drivable high and low limitations.


Test vehicle information

  F R
Vehicle weight kg 773 515
Tire size (Air pressure) kPa 225 / 40 - 18 ( 220 ) 225 / 40 - 18 ( 200 )
Wheel size 8.0 JJ × 18 inset 45 8.0 JJ × 18 inset 45
Test data in 0 mm / -3°00' out 2 mm / -2°11'
Standard value in 1.8 ± 2.0 mm / -1°23' ± 0°45' in 2.2 ± 2.0 mm / -1°55' ± 0°45'

* Test data at HKS.



Parts List   * It may be changed without prior notice. 




The ride comfort required for daily use and sports performance such as stability has been improved in a well-balanced tune without losing stock comfortability
Pursue a drivability at the specification setting, We could create suspension that the car movement easier to understand and allows the driver to have better control.
Testing various spring rates resulted in a suspension with a spring rate of F = 69 Nm (7 kg)/R = 59 Nm (6 kg) and a spring length of F = 200 mm (series barrel type)/R = 250 mm (series barrel type) that was suitable for a wide range of users
Increase high rates springs are required for use in hill climbs and mini truck or use with high grip tires (ex Yokohama A052).
When the spring rate is changed, the spring length is automatically changed to F = 170 mm/R = 220 mm. The recommended dial for damping force when rate-up is F: D = 15/R: D = 13.
When considering a circuit attack, it is recommended to swing the rear suspension's toe angle to out. Understeer becomes less to come out, and you can get on the gas pedal earlier when you stand up from the corner. Control range of understeer and oversteer are also improved.
Note: Spring setting for Full kit
※5 Spring length (mm) changes to F=170 / R=220.


Brand HKS
Shipping Weight 20.0000kg

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