Forged connecting rods Toyota 2JZ-GE / 2JZ-GTE 3.0 24v (Supra Mk4) for forged pistons

The vast majority of the connecting rods offered for the 2JZ are made from forged 4340 steel, a nickel-chromium-molybdenum alloy recognised as the benchmark for high-performance rods. Forging aligns the grain flow of the metal along the load paths, providing an excellent balance of tensile strength, toughness and fatigue endurance. After forging, the rods are machined, heat-treated and inspected to guarantee precise geometry and controlled mass.

One reference stands apart: the R-TOY-006-IP rod is produced from forged 817M40T steel, a 4340-type alloy processed to a British standard, chosen for its high mechanical properties and consistency. In both cases, these are aerospace- and competition-grade forged steels, a world away from the cast or sintered rods of mass production.

The I profile (I-Beam) takes the shape of an I in cross-section, with a central web bordered by two flanges. Naturally light, it reduces the moving mass and suits engines that favour high rpm. In its heavy-duty version it keeps this lightness while gaining strength, making it a balanced compromise between reduced inertia and solidity for a sporty 2JZ, from a prepared naturally aspirated engine to a moderate twin-turbo build.

The I-3P profile is an evolution of the I profile with three bearing surfaces, designed to combine the lightness of the I-Beam with reinforced rigidity. The material distribution optimises buckling resistance and body stability under heavy loads while keeping weight in check. This profile targets ambitious 2JZ builds seeking both a light rotating assembly and a large safety margin at high boost and high rpm.

The H profile (H-Beam) has a body relieved on both faces, revealing two parallel flanges joined by a central web, like the letter H seen in cross-section. This geometry offers excellent rigidity for a contained weight and handles compressive loads very well, which makes it particularly suited to heavily boosted engines such as the 2JZ-GTE. It is a versatile profile, valued for its robustness on high-boost builds.

ARP2000 hardware is the proven standard for high-performance rods. It offers a tensile strength of about 220,000 psi (roughly 1517 MPa) and suits the vast majority of 2JZ builds, up to an order of about 200 hp per cylinder and engine speeds reaching around 8500 rpm. On this listing the bolts are offered in 3/8 inch diameter, in 38 mm and 41 mm lengths depending on the rods.

ARP L19 hardware is a step above. This higher-performance alloy steel allows greater stresses and suits highly tuned engines, as a guide up to about 250 hp per cylinder. It is recommended when boost pressure and engine speed rise significantly. ARP L19 is more sensitive to corrosion and requires particular care during assembly and storage, in exchange for its superior strength.

ARP CA625+ hardware is the strongest grade in the range, reserved for extreme use. It is intended for very high-power engines exceeding the previous thresholds and for the highest engine speeds, up to about 10,000 rpm in extreme use. It maintains preload and rod-cap sealing under the harshest competition conditions, where the slightest loss of clamp load would be fatal.

On high-performance rods, the tightening of the cap bolts is ideally controlled by measuring bolt stretch rather than by torque alone. By measuring the elongation of the bolt between the free and tightened states with a stretch gauge, you eliminate the variations of friction under the head and in the thread, which distort the relationship between torque and actual preload.

This is the method recommended by hardware manufacturers to obtain a uniform preload across all six rods and to avoid any loosening under load. Each rod-and-hardware pairing has a target stretch range: you must reach that value, measured along the bolt axis, rather than relying on the torque wrench alone. The quoted torque remains a useful starting value when stretch measurement is not possible.

ZRP is a Greek manufacturer of forged connecting rods based in Athens, led by Alex Drakos. Its forged-steel rods are weighed and matched to within ±1 g, ensuring careful balancing of the rotating assembly. For the 2JZ, ZRP covers the H and heavy-duty I profiles, with ARP2000 or ARP L19 hardware, allowing you to secure both a prepared engine and a very aggressive configuration.

Boostline offers a specific I-3P profile for the 2JZ, designed for heavily boosted engines. The three-bearing-surface design aims for high rigidity without an excessive weight penalty. Boostline rods are offered with ARP2000 or ARP CA625+ hardware, making them suited to ambitious builds seeking a wide safety margin.

Manley is a respected American manufacturer (Wiseco group) offering an extensive range of heavy-duty H and I profiles for the 2JZ. Its rods are known for their careful manufacturing and consistency, with ARP2000 or ARP CA625+ hardware depending on the version. They are a proven choice on a great many Supra and 2JZ builds worldwide.

Wössner is a German manufacturer of high-performance forged components. For the 2JZ it offers an I-profile rod with ARP2000 hardware, geared towards an excellent balance of rigidity, weight and build quality. Wössner is a sound choice for a careful build that prioritises reliability and machining precision.