XYZ Racing Top Sport Coilovers — Infiniti QX70 (S51) 4WD 2013-2017

The S51 QX70 is a 1.9-tonne crossover riding on a sports-saloon platform, and that contradiction is exactly what its suspension has to manage. Infiniti pitched the FX/QX70 as a sport-utility that drives like a coupe, but the standard dampers were always tuned conservatively to keep the body controlled rather than to actually exploit the VQ37 or 3.0d’s reach. The XYZ Racing Top Sport coilover for the Infiniti QX70 (S51) 4WD is built for owners who want the chassis to behave the way Infiniti’s marketing promised.

Top Sport sits in the part of the XYZ catalogue aimed squarely at occasional track work paired with daily street use – which, for a 4WD QX70 owner thinking about Cadwell or a hillclimb weekend, is the realistic brief. It runs spring rates roughly 2 kg/mm stiffer than street tune and damping 30-50% firmer, sharpening turn-in and quelling the body roll the standard car carries through any committed corner.

What this coilover does for your 2013-2017 Infiniti QX70

On the S51 you feel three things on day one. Body roll on initial steering input drops noticeably, so the heavy 4WD nose stops loading the outside front tyre quite so abruptly. Squat under throttle from the QX70’s V6 weight tucks down, giving the rear axle a flatter contact patch when the all-wheel-drive system shuffles torque rearward. And the secondary ride – the small, sharp inputs from broken UK B-roads – is calmer, because the firmer damping controls wheel travel rather than letting the spring run on after each hit.

Ride height adjustment lets you set the QX70’s stance without the visual gap the OEM suspension leaves over the wheel, and the damping bandwidth means you can soften things off for the school run and firm everything up before a track session. None of this asks you to compromise the practical use of the car.

About the Top Sport coilover

Top Sport is XYZ Racing’s track-day-with-daily-driver-manners tier, with damping and spring rates developed from their own racing programme rather than borrowed off a generic catalogue. The increase of roughly 30-50% in damping force over the street setting and the 2 kg/mm bump in spring rate is the technical heart of the kit – enough to absorb the impact of poor pavement and big single bumps, while still suppressing body movement so the tyre stays loaded.

That balance is the part that’s hard to get right on a heavy 4WD platform. Too much spring and the QX70 skips across mid-corner bumps; too much damping and it crashes into expansion joints. The Top Sport tune is the result of XYZ’s circuit testing, which is why it suits track days and committed road driving without forcing you to live with a one-dimensional setup. Ride height and damping adjustment are on the unit, so once installed you can fine-tune both ends for the weight distribution and tyre choice you’re running.

Fitment for the Infiniti QX70 (2013-2017)

This kit fits the S51 chassis QX70 in 4WD form across the 2013-2017 facelift run, covering both the VQ37VHR petrol and 3.0d twin-turbo diesel variants sold in the UK and Europe. The S51 designation covers the full second-generation QX70 (and the late FX-badged cars before the 2014 rename), so chassis-code S51 4WD is the spec to confirm against your V5.

What buyers also search for

• Infiniti QX70 coilover upgrade for road and occasional track use
• S51 4WD suspension that handles UK B-road surfaces without crashing
• QX70 stance setup that keeps the car usable as a daily
• Infiniti FX/QX70 height-adjustable coilover with damping control
• 2013-2017 QX70 suspension kit for the VQ37 and 3.0d platforms

Configure your Top Sport spec for the S51 QX70 below – spring rates, damping preferences and ride height all selectable before checkout.