Manley 625EGR3-1 Extreme Duty Piston Nissan GT-R VR38DETT 95.5mm Grade 3 Single

Vehicle Fitment

• 2007-2019 Nissan GT-R (R35, VR38DETT, 3.8L Twin-Turbo V6) - Stock 88.4mm Stroke

Fitment Notes

• WARNING: CRITICAL - BORE GRADE SYSTEM: The VR38DETT uses Nissan's OEM bore grading system (Grade 1, 2, and 3). Grade 3 indicates the largest skirt diameter within the 95.5mm bore family, corresponding to the largest OEM bore grade. You MUST check the bore grade numbers stamped on the back of your engine block and order the correct grade piston for each cylinder - do NOT assume all 6 cylinders are the same grade
• This part number (625EGR3-1) is Grade 3 only - order 625EGR1-1 for Grade 1 bores and 625EGR2-1 for Grade 2 bores; most builds require a mix of grades across all 6 cylinders
• Sold individually - this listing is for ONE (1) piston with ring set, wrist pin, and wire lock; order the quantity matching the number of Grade 3 bores in your specific block
• Piston-to-wall clearance range for Grade 3: 0.0032 in.-0.0039 in. - confirm clearance with your machinist using the actual bore measurement
• Designed for stock 88.4mm stroke VR38DETT builds only - not compatible with stroker kits using a different crank throw
• Wrist pin diameter is 23mm - verify connecting rod pin bore compatibility before pairing with aftermarket rods
• Turbo Tuff/DLC wrist pin upgrades (P/N 42745 .250 in. wall and P/N 42746 .300 in. wall) are available separately for maximum-effort builds
• Will accommodate +1mm valve sizes - compatible with ported heads using slightly larger valves
• No manufacturer warranty - Manley Performance does not offer warranty on pistons due to their performance-oriented intended use
• Professional engine builder installation required

Features

• Platinum Series Extreme Duty designation - the highest-specification single-piston offering in Manley's VR38DETT stock-stroke lineup, featuring a 9310 alloy wrist pin (.210 in. wall) for significantly greater pin strength compared to the standard chrome moly pin (.180 in. wall) used in the non-Extreme Duty 625GR series
• Forged 2618 aluminum alloy construction - delivers maximum high-temperature strength, fatigue resistance, and ring land durability under the sustained high-boost, high-RPM conditions of heavily modified GT-R builds
• Near-flat top piston design (-1.5 cc dome volume) produces a 9.25:1 compression ratio - well-suited for high-boost forced induction builds on pump gas or E85
• Grade 3 skirt diameter corresponds to OEM VR38DETT Grade 3 bore specification, producing a piston-to-wall clearance of 0.0032 in.-0.0039 in. when installed in a properly sized cylinder
• Offset wrist pin design reduces piston-to-cylinder wall impact at TDC for quieter cold starts and reduced piston slap during warm-up
• Moly-coated (anti-friction) skirts reduce friction and wear, improving break-in and thermal management throughout the piston's service life
• Pressure balance groove equalizes pressure across the top ring land for more consistent ring seal and improved combustion efficiency
• Proprietary multi-step top ring groove machining process using "one fixturing" method ensures perfect ring groove-to-skirt squareness and precise groove geometry for maximum ring sealing and power
• Federal Form-Scan gauging used to validate ideal skirt indexing to pinhole and skirt-to-skirt polarity for consistent quality across every unit
• Precise pinhole machining delivers exact compression distance and precise lock ring groove concentricity
• "Contour forging" design provides optimal balance between strength and weight without grain-interrupting internal milling
• Premium Steel 1.2mm top ring set with 1.2mm Napier second ring and 9-13 lb. tension 3mm oil ring from Total Seal included

Specifications

• Series: Platinum Series, Extreme Duty
• Material: Forged 2618 Aluminum Alloy
• Piston Type: Near-Flat Top (Slight Dish)
• Bore Grade: Grade 3 (largest OEM VR38DETT bore grade)
• Bore Size: 95.5 mm
• Stroke: 88.4 mm (Stock)
• Rod Length: 6.500 in.
• Dome Volume: -1.5 cc
• Compression Ratio: 9.25:1
• Piston Weight: ~449 grams
• Piston-to-Wall Clearance Range: 0.0032 in.-0.0039 in. (Grade 3)
• Wrist Pin Series: Extreme Duty
• Wrist Pin Material: 9310 Alloy
• Wrist Pin Part Number: 42546
• Wrist Pin Wall Thickness: 0.210 in.
• Wrist Pin Weight: 147 grams
• Wrist Pin Length: 2.500 in.
• Wrist Pin Diameter: 23mm
• Skirt Coating: Moly (Anti-Friction)
• Ring Set: Premium Steel 1.2mm Top / 1.2mm Napier Second / 9-13 lb. 3mm Oil (Total Seal)
• Quantity: 1 (Sold Individually)
• Country of Origin: USA

Included Components

• 1x Manley Platinum Series Extreme Duty forged 2618 piston (95.5mm Grade 3, moly-coated skirts)
• 1x 9310 alloy Extreme Duty wrist pin (23mm / 0.210 in. wall, P/N 42546)
• 1x Complete ring set (1.2mm Premium Steel top, 1.2mm Napier second, 9-13 lb. 3mm oil - Total Seal)
• 1x Round wire wrist pin lock

Product Description

The Manley 625EGR3-1 is a single Platinum Series Extreme Duty forged piston for the Nissan R35 GT-R's VR38DETT 3.8L twin-turbo V6 engine at stock 88.4mm stroke and 95.5mm bore. The "E" in the part number designates the Extreme Duty spec, which upgrades the wrist pin from the standard chrome moly unit to a heavier-wall 9310 alloy pin (0.210 in. wall, P/N 42546) - a critical enhancement for high-powered GT-R builds where pin loading under extreme boost can exceed the capability of a standard-wall pin. The "GR3" suffix designates this as the Grade 3 bore variant, meaning the piston's skirt diameter corresponds to Nissan's OEM Grade 3 bore specification, producing the tightest fit within the Grade 1/2/3 clearance range of 0.0032-0.0039 in.

The near-flat top piston design (-1.5 cc dome volume) produces a 9.25:1 compression ratio - appropriate for aggressive boosted GT-R builds on pump fuel or E85 where the elevated compression aids power production without exceeding detonation limits under controlled boost and ignition timing. The piston is machined from forged 2618 aluminum alloy with moly-coated skirts, an offset wrist pin for cold-start NVH reduction, and a pressure balance groove for consistent ring sealing. The 1.2mm top ring / 1.2mm Napier second / 9-13 lb. 3mm oil ring set from Total Seal is included with each unit, along with the 9310 alloy wrist pin and round wire lock.

Ordering this piston correctly requires understanding the VR38DETT bore grade system. Nissan grades each cylinder bore at the factory as Grade 1 (smallest), Grade 2, or Grade 3 (largest). These grades are stamped on the back of the engine block. Before ordering, you must identify the bore grade of every cylinder in your specific block and order the correct grade piston(s) for each. Most blocks have a mix of grades across all 6 cylinders. This listing (625EGR3-1) covers Grade 3 bores only. Order 625EGR1-1 for Grade 1 and 625EGR2-1 for Grade 2 bores. This part is sold as a single unit - order the quantity equal to the number of Grade 3 bores in your block. Professional installation by an experienced GT-R engine builder is required. Manley does not offer a warranty on performance pistons.