Performance Crankshafts

The best performance crankshafts are forged or billet cranks matched to your engine, stroke, and power goal: Manley Performance Turbo Tuff cranks serve Subaru EJ20 and EJ25 and Mitsubishi builds, K1 Technologies offers billet and stroker cranks for Nissan SR20 and Mitsubishi 4G63 engines, and Brian Crower covers SR20, 2JZ, and VQ35DE combinations. Treat the crank, rods, and pistons as one decision.

The crankshaft converts the pistons' motion into rotation and takes the full force of every combustion event. A performance crank adds strength for higher power and rpm, and a longer stroke increases displacement, which usually brings more torque. Stroker combinations also change piston speed and rod angle, so crank, rods, and pistons must be selected together and balanced as one assembly.

When you compare cranks, confirm the engine and bolt pattern first, because Mitsubishi 4G63 cranks differ between 6-bolt and 7-bolt engines. Next, decide on stroke: standard-stroke cranks suit high-rpm builds, while strokers trade some rpm headroom for displacement. Finally, consider material and weight, and always check your year and model.

Manley Performance is a core engine-internals name here, and its Turbo Tuff Series cranks are built for boosted applications. The range includes 75mm and 79mm cranks for WRX and STI EJ20 and EJ25 engines, a crank for the 1993-1999 Eclipse 7-bolt, and a 4340 billet 94mm stroke crank for the Mitsubishi Evo X. The Manley Turbo Tuff 79mm crank for EJ20 and EJ25 is the Subaru starting point.

K1 Technologies focuses on rotating-assembly components, and its lineup here spans a billet 92mm stroke crank for the Nissan SR20DE and SR20DET plus standard-weight and lightweight 100mm cranks for the 1993-1999 Eclipse. Both weights for one application let a builder choose response or durability. K1 pairs naturally with the connecting rods that complete the assembly.

Eagle is the 4G63 specialist here, with stroker cranks for the 7-bolt Mitsubishi Evo 8 and 9 and 6-bolt 1990-1992 Eclipse engines, in 94mm and 100mm strokes. Brian Crower covers the Nissan and Toyota side with 4340 billet cranks: 91mm stroke SR20 cranks, 94mm stroke 2JZ-GTE and 2JZ-GE cranks in standard and lightweight form, and 88.0mm VQ35DE cranks for the Nissan 350Z and Infiniti G35, in balanced and unbalanced versions. HKS also appears with its 2.2L stroker kit for the Mitsubishi Evo X, for builders who prefer a matched kit.

Before committing to a stroker, read our overview of how long WRX and STI engines last.

What does a stroker crankshaft do?

It increases piston travel, which raises displacement. That usually adds torque and midrange power, at the cost of higher piston speeds, so rods, pistons, and tuning must suit the longer stroke.

What is the difference between 6-bolt and 7-bolt 4G63 cranks?

The terms describe how the flywheel attaches, and the cranks are not interchangeable. Early Eclipse 4G63 engines are 6-bolt and later ones 7-bolt, so verify your engine first.

Does a new crankshaft need balancing?

Yes. Balance the crank with your rods, pistons, and damper as one assembly. Some cranks here are sold balanced and others unbalanced, so read the listing and budget for machine-shop work.

Can I install a performance crankshaft at home?

A crank swap is a full engine build: the block comes apart and bearing clearances must be measured precisely. Most owners should treat it as engine-builder work.