CP Pistons SC7708-6 Forged Piston Set for 2019-2025 BMW S58B30 3.0L I6 9.3:1

Vehicle Fitment

• 2019-2025 BMW X3 M / X4 M / M3 / M4 / M2 (S58B30; RWD / AWD)

Fitment Notes

• Pistons are intended for the S58B30 3.0L twin-turbo inline-6 engine.
• Not compatible with B58, N55, S55, or N20/N55/N54 engines.
• Standard bore (84.00 mm) only; block must be in good condition.

Features

• Forged 2618 aluminum for high strength and thermal resistance.
• Compression ratio of 9.3:1 to match standard S58 spec for power and reliability. :contentReference[oaicite:0]{index=0}
• Standard bore size of 84.00 mm to maintain compatibility. :contentReference[oaicite:1]{index=1}
• Includes full set of 6 pistons with all required hardware (pins, rings, locks). :contentReference[oaicite:2]{index=2}
• CNC-machined for precise tolerances across all pistons. :contentReference[oaicite:3]{index=3}
• Designed for high-performance applications; durable under boost. :contentReference[oaicite:4]{index=4}
• Optimized dish volume for combustion efficiency in stock S58 head. :contentReference[oaicite:5]{index=5}
• Balanced set to reduce vibration and improve reliability at high RPMs. :contentReference[oaicite:6]{index=6}

Specifications

• Number of Pistons: 6
• Bore Size: 84.00 mm (standard) :contentReference[oaicite:7]{index=7}
• Compression Ratio: 9.3:1 :contentReference[oaicite:8]{index=8}
• Material: Forged 2618 aluminum alloy :contentReference[oaicite:9]{index=9}
• Stroke: 90.00 mm (engine spec) :contentReference[oaicite:10]{index=10}
• Connecting Rod Length: 137 mm :contentReference[oaicite:11]{index=11}
• Pin Diameter: 23 mm (≈ 0.905") :contentReference[oaicite:12]{index=12}
• Compression Height: ~1.39 in / ~35.3 mm :contentReference[oaicite:13]{index=13}

Included Components

• 6x Forged Pistons (SC7708-6)
• 6x Wrist Pins
• 6x Ring Sets
• Locks (pins locking clips)
• Spec Sheet / Installation Guide

Product Description

The CP Pistons SC7708-6 is a high-performance forged piston set built for the BMW S58B30 3.0L twin-turbo inline-6 engine, used in modern M-division models from 2019 through 2025. These pistons maintain the factory bore (84.00 mm) with a 9.3:1 compression ratio, offering reliability and durability under boosted conditions while preserving the stock combustion chamber design.

Crafted from 2618 forged aluminum, each component in this set is CNC-machined and precisely dimensioned. The 137 mm connecting rod, 90 mm stroke, and included hardware make this a complete solution for builds where strength is essential. Whether you're replacing worn stock pistons or building for higher output, this set delivers performance with OEM compatibility.

Fitment is confirmed through 2025 for all S58B30-powered BMW models listed. Before installation, ensure your engine uses the standard bore, and verify clearances especially if upgrading turbos, heads, or compression-height components.