~80 %
TORQUE FROM LOW REVS
The ZPJ4 is PSA's own take on the PRV V6: four valves per cylinder, a variable-geometry ACAV intake, 200 naturally-aspirated bhp — a different breed from Renault's Z7X, and the base of the most powerful PRV road car ever.
ACAV stands for “Admission à Caractéristiques Acoustiques Variables”. Instead of a fixed manifold, a plenum — a “lung” — and butterfly valves change the effective length of the intake runners with engine speed: below about 5,200 rpm, the long runners exploit the resonance of the intake pressure waves to swell torque; higher up, the geometry opens to free top-end power.
The result: nearly 80% of the torque available from low revs — flexibility AND reach, on a naturally-aspirated V6. Early units, though, suffered camshaft problems and chaotic fine-tuning; the full context is in our History section.
The first 24-valve PRVs — a PSA-specific engine with its own cylinder heads and the ACAV intake, launched in 1989 on the 2,963 cc block. Renault stayed faithful to turbos and 12-valve engines.
Starting from the ≈200 bhp ZPJ4, the engine house EIA fitted two Garrett turbos for the Venturi 400 GT (2,975 cc): 408 bhp, the most powerful road car ever powered by the Douvrin V6 — nicknamed “the French F40”. Details in our Tuners section.
The ZPJ4 is a PRV. The 60° ES9 (Peugeot) / L7X (Renault) that replaced the PRV on the 605, XM, Safrane and Laguna from 1997 is a different engine — despite similar displacements.
The 2.5 turbo, the Renault 3.0, and every known engine code of the PRV V6.