1983-1986 Porsche 928S

Overview

The 928S4 elevated performance positioning through a 5.0-liter V8 engine producing 316 horsepower in American specification, establishing enhanced grand touring capability. Produced from 1987 through 1991, this variant represented significant performance improvement over the 928S through displacement increase and revised engine optimization. The 5.0-liter displacement reflected Porsche engineers' strategy to extract maximum sustainable power output from naturally aspirated V8 architecture.

The S4 designation signified substantial enhancement, attracting buyers seeking measurable performance increase without accepting forced-induction complexity. The 5.0-liter displacement represented a 300-cubic-centimeter increase from the 4.7-liter S model, providing substantial additional horsepower and torque for improved acceleration responsiveness.

Engineering & Development

The 5.0-liter V8 features an aluminum block with cast iron cylinder liners, employing variable valve timing and port fuel injection. The engine produces 316 horsepower at 5,500 rpm, with peak torque delivered across a broad operating range. The compression ratio optimization enables responsive power delivery without requiring premium-grade fuel specifications.

The transmission employs a four-speed automatic unit with torque converter lock-up and refined shift programming optimized for increased V8 torque. The suspension incorporates reinforced anti-roll bars and revised damper calibration reflecting the additional engine output. The steering system provides improved feedback through enhanced hydraulic characteristics.

The braking system specifies larger ventilated rotors and enhanced friction materials, providing increased stopping power. The cooling system receives substantially larger radiator capacity managing thermal loads from the 5.0-liter displacement.

Market Variants

The 928S4 represents the performance intermediate, featuring sport-oriented suspension tuning and enhanced interior appointments. The leather upholstery receives premium stitching and enhanced bolstering. The sport exhaust provides distinctive audio enhancement. The optional air conditioning improves daily practicality.

The wheel specification measures 16 inches as standard, fitted with performance-oriented tires. The interior emphasizes refined comfort and functional ergonomics suitable for grand touring applications.

Significance

The 928S4 demonstrates Porsche's commitment to extracting maximum power from naturally aspirated V8 displacement, validating that larger engines deliver satisfying grand touring performance. The 316 horsepower output proves that 5.0-liter naturally aspirated V8s provide competitive performance. The model validates continued 928 development strategy.

The 928S4 proved that naturally aspirated engines remain viable for meaningful performance delivery.