HKS Hipermax Touring Height-Adjustable Springs – Toyota GR Supra A90/A91 and BMW Z4 M40i G29

OVERVIEW

Most GR Supras and Z4 M40is leave the factory with electronically controlled adaptive dampers — an expensive, well-sorted system that you lose the moment you fit conventional coilovers. HKS's view was that the best option for many owners is to keep those dampers and just fix the ride height. The Hipermax Touring kit does exactly that: a height-adjustable spring set that works with the factory adaptive dampers, so Comfort and Sport modes keep working exactly as before and no error canceler is needed.

The kit lowers the car by up to about 45 mm and lets you choose the height you want with the included adjuster, which uses the stock lower spring seat. The springs are a variable-pitch barrel design that steadies the body, and HKS developed a new, more durable rear bump rubber for lowered use. The setup was chosen after testing at Fuji Speedway and Gunma Cycle Sports Center with racing driver Manabu Orido.

The same kit fits the BMW Z4 M40i (G29), which HKS fitted and confirmed on an actual car — but only Z4s with Adaptive M Suspension. The Z4 is heavier than the Supra, and at HKS's factory height its front aluminum undercover sits 93 mm off the ground.

SPECS

• Type: height-adjustable spring kit for use with the factory adaptive dampers
• Spring rates: front 43 N/mm (4.3 kgf/mm), rear 117 N/mm (11.9 kgf/mm)
• Spring type: variable-pitch barrel, HKS special length
• Ride height adjuster works with the stock lower spring seat
• HKS rear bump rubber developed for lowered use
• GR Supra 3.0 (DB42): front −25 mm default (−25 to −48 mm), rear −20 mm default (−20 to −53 mm)
• GR Supra 3.0 (DB02): front −29 mm default (−29 to −52 mm), rear −24 mm default (−24 to −57 mm)
• GR Supra 3.0 manual (DB06): front −25 mm default (−25 to −52 mm), rear −18 mm default (−18 to −55 mm)
• GR Supra 2.0 (DB22): front −16 mm (−16 to −39 mm), rear −19 mm (−19 to −52 mm); HKS recommended setting F −18 / R −19 mm
• BMW Z4 M40i (G29): front −21 mm default (−21 to −44 mm), rear −19 mm default (−19 to −52 mm)
• Made in Japan

PARTS INCLUDED

• Front and rear HKS springs (set of four)
• Ride height adjusters
• HKS rear bump rubbers
• HKS installation manual

TECH RESOURCES

• Required extras: none. The factory adaptive dampers and their wiring stay in place, so the Suspension Error Canceler is NOT required.
• Dust boots: the stock dust boot will not fit with this kit. HKS makes a dedicated boot for owners who want one — ask us to add it to your order.
• Required after install: a full four-wheel alignment.
• Installation manual (HKS): 80280-AT001 Hipermax Touring installation manual (PDF)
• Installation notes: professional installation recommended. The factory springs are swapped on the factory dampers, the bump rubber is modified per the manual (required on GR Supra 3.0 DB42 / DB02 and Z4), and ride height is set at the adjuster.
• Z4 note: only for Z4 M40i cars with Adaptive M Suspension. HKS warns that raising the Z4 above its factory setting can let the spring coils bind at full bump.
• Not for: GR Supra 2.0 with conventional (non-adaptive) dampers (DB82). For those cars, see the HKS Hipermax S coilovers.
• ADAS: have the Toyota Safety Sense / BMW driver-assist radar and camera calibration checked after lowering.
• Price is for the item only; labor is not included.

PART NUMBER

• 80280-AT001 — HKS Hipermax Touring Height-Adjustable Spring, Toyota GR Supra and BMW Z4 M40i (G29)

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