Sunny Coupe 1200GX-5

Datsun built the Sunny Coupe 1200GX-5 (KB110) from 1972–1973. The Sunny 1200GX-5 supplied a factory five-speed road-car base for a highly successful Japanese touring-car programme. Its two-door fastback coupé form and compact sports coupé purpose locate it within a specific chapter of the marque’s performance history.

This corrected identity is the August 1972 Japanese-market production GX-5 coupé, not a Sunny Truck, the restored 1975 TS race specification or another B110 grade. That scope is important: familiar badges can cover several engines, markets and model years, while road cars and competition derivatives may share a name without sharing a usable technical specification.

The mechanical centre is the A12, a 1,172 cc naturally aspirated inline-4. The period specification represented here is 61 kW (83 PS) and 98 Nm. Those figures stay attached to this configuration rather than blending regional tunes or later revisions.

The road-going A12 GX twin-carburettor engine is paired with a close-ratio direct-fifth manual gearbox unique to the GX-5. The installation is longitudinal front engine, rear-wheel drive, working through a 5-speed manual. That combination determines throttle response, traction and the path by which induction, combustion and transmission sound reach the cabin and roadside.

Useful listening markers include twin-carburettor A12 inline-four, close-ratio five-speed manual, rear-drive live axle, light fastback cabin. A genuine cold start records cranking, first combustion and the transition to a settled idle; a warm restart is a different event and should be labelled as such.

Under acceleration, microphone position and engine load reveal different layers. An engine-bay or cabin recording can expose induction and valvetrain detail, while an exterior pass gives more weight to exhaust, tyres, turbocharger or supercharger behaviour and the acoustic effect of speed.

The KB110 identity also makes comparisons within the Sunny family meaningful. Closely related editions may differ in intake hardware, boost control, gearing, catalysts, silencers or mass, so their recordings should not be treated as interchangeable merely because the body shell looks similar.

Surviving examples frequently carry replacement exhausts, wheels, suspension or engine parts. Those cars can still make valuable contributions when the changes are documented; the archive simply needs to distinguish a modified survivor from an evidenced factory-stock reference.

The 1972–1973 production period supplies another boundary for research. Manufacturers revised emissions calibrations, equipment and market availability during model runs, and historic output may appear in PS, kilowatts or regional horsepower standards. Keeping units and market context visible prevents false precision.

Body layout matters to sound as much as specification sheets suggest. The two-door fastback coupé changes cabin volume, resonance and the listener’s distance from the powertrain. Engine position, driveline and body openings can therefore make related engines feel substantially different in use.

Period photographs establish design and historical context, but appearance alone cannot prove untouched mechanical condition. Originality should be described component by component, especially for intake, forced induction, catalysts, silencers, transmission and final-drive hardware that can alter performance and sound. Service records and dated photographs can make those distinctions clearer without asking readers to accept appearance as proof.

The Sunny Coupe 1200GX-5 is therefore best understood as a connected mechanical identity: A12, 5-speed manual, rear-wheel drive and the KB110 boundary. Preserving those elements gives readers a useful story now and gives future community recordings an exact historical home.