XYZ Racing Pro Racing Gravel/Snow Coilovers — Maserati BITURBO SI φ52 welding (PCD: 4X98) 1986-1991

The Biturbo SI’s twin-turbo V6 sits well forward of the front axle, a layout that made these 1986-1991 cars notoriously nose-heavy the moment the surface changed underneath them – exactly the weight transfer a rally stage or a snow-packed hillclimb will expose on the first hard braking into a hairpin. XYZ Racing’s Pro Racing Gravel/Snow coilover kit is built around that reality. Extended front and rear travel keeps the wheel loaded over ruts and washboard instead of slamming into the bump stops, which matters more on a Biturbo than on most rally cars, since there is no factory motorsport development to fall back on.

Fitting this kit means welding in a 52mm strut body rather than bolting to an existing top mount – a deliberate choice on a chassis this old, where XYZ Racing’s own perch geometry replaces whatever remains of the original mount after three and a half decades. The 4×98 PCD bolt pattern is confirmed against the Biturbo’s hub before the kit ships, so the geometry lines up without spacers or adapter plates.

What this coilover does for your 1986-1991 Maserati Biturbo SI Φ52 Welding (PCD: 4×98)

Off tarmac, the biggest single change is travel. The Pro Racing Gravel/Snow kit’s longer-stroke dampers let the Biturbo’s springs absorb a compression event fully instead of transmitting it straight into the chassis, which keeps the nose-heavy V6 from diving and losing front grip mid-corner. The three adjustment knobs let you separate compression and rebound enough to soften the ride for a loose gravel stage in the morning and firm it back up for a hard-packed snow test in the afternoon, without pulling the dampers off the car. Extra suspension oil and nitrogen gas volume inside each unit gives the shock more thermal mass to draw on, so a long stage or repeated hillclimb runs do not cook the damping the way a smaller-volume unit would. You may hear a faint tick as oil passes through the small metering holes on a big compression – that is the valving doing its job, not a fault.

About the Pro Racing Gravel/Snow coilover

XYZ Racing built the Pro Racing Gravel/Snow line for rally and rallycross use, where the car needs to survive repeated big hits rather than hold a single static ride height. Front and rear travel is stretched beyond XYZ’s tarmac-biased kits specifically to create a larger buffer before the suspension runs out of stroke on rough or rutted ground. Each damper carries a larger reservoir of suspension oil and nitrogen gas than a standard road kit, which gives the shock more capacity to shed heat during a long stage instead of the oil thinning and the damping fading before the stage is finished. The three external adjustment knobs work through deliberately small metering passages, a design that trades a small amount of noise on hard compressions for finer control over how the oil moves through the valving. XYZ built the kit around sustained circuit and stage use, so the damping characteristics hold up over a full day of driving rather than fading after the first few hard runs.

Fitment for the Maserati Biturbo SI Φ52 Welding (PCD: 4×98) (1986-1991)

This kit is built for the Maserati Biturbo SI, chassis code MS03, across the 1986 to 1991 production run. The φ52 Welding mount is designed to be welded directly to the strut tower rather than bolted through an OEM top mount, and the kit is set up for the Biturbo’s 4×98 bolt pattern.

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A Biturbo built for stages rather than showrooms deserves dampers set up the same way – pick your Pro Racing Gravel/Snow spec below and build yours to suit the surface you actually drive.