XYZ Racing Circuit Master Coilovers — Infiniti Q45 (G50) Front top mount: 116mm / Front lower mount: φ20 1989-1997

The G50 Q45’s factory air suspension was built to smooth out motorway expansion joints, not to keep a heavy naturally aspirated V8 saloon flat through a fast direction change – and that’s the gap the XYZ Racing Circuit Master closes. This is a monotube coilover kit built around sustained circuit lap-time work: the kind of session where the suspension is loaded corner after corner rather than for one fast pull down a B-road.

For a car most people wrote off as too heavy and too soft to take seriously on track, Circuit Master gives owners of the front top mount: 116mm / front lower mount: φ20 spec Q45 a way to control that mass properly, instead of fighting it with stiffer anti-roll bars alone.

What this coilover does for your 1989-1997 Infiniti Q45

Fit the Circuit Master and the first thing you notice is how much of the V8’s front-end mass stays under control mid-corner instead of arriving at the apex a beat late. The kit’s 9720-way damping adjustment, set through three external knobs, lets you tune compression and rebound independently enough to stop the nose diving under trail-braking into a hairpin – a genuine weakness on the stock air suspension. Ride height drops enough to lower the centre of gravity without pushing the geometry out of range, which matters on a chassis this heavy. Track sessions expose body roll fastest, and a firmer, height-adjustable platform keeps the outside tyre loaded evenly through a full session rather than rolling onto the sidewall by the third or fourth lap.

About the Circuit Master coilover

XYZ Racing built the Circuit Master as its dedicated circuit-day product, developed and run through XYZ’s own racing teams on international circuits before it reached retail. The headline figure is 9720 possible damping combinations across the kit’s three external adjustment knobs, a far finer window than a single-knob coilover offers for matching the setup to a specific track surface or session length. That adjustment range comes from a monotube design with a small-diameter oil passage; XYZ notes that under heavy compression, such as a kerb strike or a badly cambered apex, that passage can produce a faint noise as oil moves through it. That’s a characteristic of the design rather than a fault, and the kit is built around repeated circuit loading rather than the odd pothole on the commute. On a low-volume platform like the Q45, that circuit-first brief is the reason to pick Circuit Master over a road-biased kit.

Fitment for the Infiniti Q45 (G50) (1989-1997)

This kit is specced for the G50-generation Q45, built from 1989 to 1997, matching the factory front top mount at 116mm and a front lower mount diameter of φ20. Confirm those two front mounting dimensions against your car before ordering, since hardware varied within the G50’s production run and a mismatch shows up as a bolt-hole or shaft-diameter problem at fitting, not on paper.

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Pick your Circuit Master spec for the G50 Q45 below, matched to your car’s front mount dimensions.