JE Pistons 389618 Ultra Series BMW-Toyota Forged Piston Kit Bore - B58B30 83.00mm 6-Cylinder

The JE Pistons 389618 Ultra Series Piston Kit is a complete six-cylinder forged piston set engineered specifically for the BMW-Toyota B58B30 3.0L turbocharged inline-six engine. With an 83.00 mm bore, 30.91 mm compression height (CD), and a -12.00 cc dish volume, this kit is precision-designed for high-output performance builds on the B58 platform.

Key Specifications:

• Bore: 83.00 mm (3.268 in.)
• Compression Distance (CD): 30.91 mm (1.217 in.)
• Dish Volume: -12.00 cc (inverted dome/dish)
• Alloy: 2618 forged aluminum
• Engine Application: BMW-Toyota B58B30

Key Features:

• 2618 forged aluminum construction delivers the high tensile strength required for forced-induction and high-demand performance applications
• Proprietary Forged Side Relief (FSR) design minimizes friction and power loss through a reduced-width skirt and shorter wrist pin for additional weight savings
• Skirt coating reduces friction and wear between piston skirts and cylinder walls while lowering operating noise
• Accumulator groove reduces combustion gas pressure on the ring pack, limiting ring flutter and improving ring seal for consistent power output
• Engineered, forged, and machined 100% in the USA to exacting tolerances for each specific engine and racing application
• Complete kit includes wrist pins, locks, and JE Pro Seal premium piston rings

JE Pistons brings over 75 years of forged racing piston expertise to every set, with a track record validated across drag racing, drift competition, and road racing at the highest levels. The Ultra Series B58B30 piston kit is an ideal foundation for serious engine builds targeting reliability and power on this platform.