HKS Hipermax IV GT Suspension Subaru Impreza GRF

â–²The above photo is an item for ZN6.

Awesome control and comfort ride on the street for a sporty drive. The new Max IV sporty suspension.

Application

　

Specification

Engine

EJ25(TURBO)

Model Year

09/02 -

Remarks

　

FRONT

REAR

Damping force adjustment

30 steps

30 steps

Base valve

-

-

Height adjustable lower bracket

â—‹

â—‹

Upper mount

Rubber

Rubber

Inverted/Normal type

Inverted

Normal

Damper/Spring layout

Coilover

Coilover

Spring rate change at factory

Possible

Possible

Damping force adjustment with wire

-

-

Helper spring
(Spring rate N/mm)

-

-

Ride Height

mm

Factory *2

Test data

Adjustable range
High - Low *3

Drivable range
High - Low *4

FRONT

Ride height *1

654

←

685 ～ 606

685 ～ 646

Against stock

-31

←

0 ～ -79

0 ～ -39

REAR

Ride height *1

650

←

684 ～　596

684 ～　615

Against stock

-34

←

0 ～ -88

0 ～ -69

*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)

78 ( 8 )

59 ( 6 )

Free height (mm)

220

200

Spring type

Straight Barrel type

Straight

Recommended range to change spring rate N/mm(kgf/mm)

±20 ( 2 )

±20 ( 2 )

Specification of damper

F

R

Damping force (Rebound/Damping)N*

1422 / 373

461 / 177

Default position of dial

15

15

Remaining damper stroke (Rebound/Damping)mm

47 / 69

40 / 60

* 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)

269

←

297

265

253

←

268

233

Spring
Set length(mm)

217

←

←

220

195

←

185

200

Length to ride hight
adjuster (mm)

63

←

91

56

39

←

64

14

Lever ratio

1.10

1.38

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

Test vehicle information

F

R

Vehicle weight kg

893

627

Tire size (Air pressure) kPa

245 / 40 - 18 ( 230 )

245 / 40 - 18 ( 190 )

Wheel size

9.0 JJ × 18 off 45

9.0 JJ × 18 off 45

Alignment
(Toe/Camber)

Test data

0 mm / -2°36'

0 mm / -1°42'

Standard value

0 ± 3 mm / -0°40' ± 45'

0 ± 3 mm / -1°35' ± 45'

* Test data at HKS.

Parts List * It may be changed without prior notice.

Point

・It didn't give up the driving performance and at the same time it provides comfort in town driving. MAX IV has advanced even more from the MAX III.
・We have adopted newly developed needle and variable port system for both front and rear that makes damping force at the low speed range, which is very important for comfortable and great steering with no upthurst and floating feel.
・With the new design of piston and M shaft for rear damper provides better oil pressure that gives comfortable dive.
・The damping level can be adjusted with dial for slow drive or winding road drive or all other type of situation.
・The normal rear damper has not so good driving experience but the MAX IV provides awesome feeling and performance in dri...