Subaru Oil System Upgrades - Import Tuner Magazine

Lateral and longitudinal forces from turns, acceleration, and braking, especially in drifting and road race vehicles, could push oil around the floor and up the side of the pan, starving the pickup under high-rpm/high-lateral g conditions. This is a common problem for high-performance engines. The Subaru EJ engine is notorious for oiling problems. From spun rod/crank bearings to occasional faulty oil pickup units, this engine has been begging for an aftermarket fix to prevent such mishaps from occurring. Killer B Motorsport out of Waynesboro, VA, specializes in aftermarket Subaru components. KBM offers a number of upgraded oiling parts, including a more robust oil pickup, oil pan baffle, and larger-capacity oil pan.

OEM Subaru EJ205 Oil Pan

Here’s a close-up inside the OEM ’02-05 Subaru WRX oil pans designed with a flat belly surface. You can see that it already has a built-in baffle, but it does not provide enough flow control by itself to prevent oil starvation in high g-force turns.

KBM Optimal Oil Pan

The Optimal Oil Pan holds an extra 1.3 quarts of oil, a 30 percent increase in capacity over OEM. KBM uses 1⁄8-inch-thick CNC-formed aluminum sheet to make the pan. For added convenience, the pan comes with two ½-inch NPT drain/sensor ports in the CNC-machined billet aluminum drain block. The aluminum baffles built inside the pan are an improvement over the OEM designs to concentrate the oil closer to the pickup, making it more stable and less prone to oil flow fluctuations. The oil pan’s compact design, based off of the OEM EJ25 pan allows it to be compatible with numerous aftermarket headers.

KBM Windage/Baffle Tray

When running high rpm the oil is pumping faster and is under more pressure, which creates windage, an oil foaming condition that causes parasitic drag on the crankshaft caused by oil splashing out of the sump at high rpm, keeping the oil from settling back into the pan. Poor internal oil circulation keeps it from returning to the pan, causing the oil pickup to surge and, in many cases, starve the oil pump. A baffle pan’s real purpose is to slow the return of the oil back into the pan. It is designed for the oil to fall on it so that air can escape the oil suspension where it then gets picked back up. The KBM windage tray features numerous advantages over the OEM piece, including a closed rear section to prevent oil from sloshing into the crank under hard acceleration and aggressive shifts, a block contoured profile to minimize oil returning from the heads interfering with the crank, and directional louvers to prevent oil in the pan from splash/sloshing into the crank.

OEM Oil Pickup

Replacing the OEM oil pickup is a good idea, regardless of how you drive your car. An alarming number of Subaru owners have claimed that their factory-welded/brazed oil pickups have cracked at the base (shown with our pointer) of the pickup tube. A cracked pickup very rarely has any symptoms. If they do, it’s an occasional oil light flicker at idle. The time between the initial crack formation and propagation to complete failure is more often than not, a rapid progression that gives little to no warning (see pic with carnage). A dented or damaged pickup can severely inhibit the flow of oil into the engine causing oil starvation.

Killer B Oil Pickup

The KBM Ultimate oil pickup has become a popular upgrade among Subaru owners. The pickup uses a .12-inch-thick double bracket, three-times OEM oil pickup tube thickness, and a brace between the bracket and the oil pickup tube to further strengthen the assembly. This highly reinforced pickup is a direct fit for all 2.5L ’04-09 STI, ’06-09 WRX, and LGT. The ’02-05 EJ20 WRX requires 2.5L oil pan for fitment.