COBB Lightweight Crank Pulley Subaru Impreza 2.5 GT (2009-2010) Black - 300102

Fitment Information

• Subaru Impreza 2.5 GT (2009, 2010) 

Specs & Features

• Featherweight Fighter: Precision CNC machined from Billet 6061-T6 Aluminum, weighing in at a mere 1.2 lbs—that is a 4lb weight reduction over stock!
• No "Under-Drive" Headaches: Engineered to maintain the exact Stock Diameter, ensuring your alternator, A/C, and power steering keep running at factory speeds without triggering electrical warning lights.
• Physics Upgrade: drastically reduces Rotational Mass, meaning your engine wastes less energy spinning the pulley and puts more energy into the wheels.
• Built to Survive: Finished in a hard Anodized Black to withstand engine bay heat, corrosion, and grime while looking stealthy.
• Simple Install: Matches the factory drive belt surface perfectly, making this a quick, bolt-on upgrade for even the novice mechanic.

Product Description

Let’s talk physics for a second: "Rotational Mass" is the enemy of performance. Think of it like trying to spin a heavy steel bicycle wheel versus a lightweight carbon fiber one. The heavy one takes way more energy to get moving. The factory main pulley on your engine is a heavy, cast-iron lump that acts like a parasite, stealing horsepower just to keep itself spinning. COBB Tuning solves this by putting your crankshaft on a crash diet. By swapping to a CAD-designed, CNC-machined 6061-T6 Billet Aluminum pulley, you are dropping over 4 pounds of dead weight off the nose of the crank.

The result? The moment you touch the gas, the engine revs freer and faster. It isn't just about peak horsepower; it is about response. But here is where COBB is smarter than the other guys: many aftermarket pulleys are "under-driven" (made smaller) to save weight, which slows down your accessories and causes dim headlights or dead batteries. COBB Tuning kept the Stock Diameter intact. You get all the benefits of the lightweight material without the electrical nightmares or the need for a weird-sized custom belt. It is the perfect balance of performance physics and daily-driver reliability. Swap it out, keep your voltage up, and let that engine sing.