All-Billet Subaru EJ 2.5L Engine - Engine Builder Magazine

All-Billet Subaru EJ 2.5L Engine

This 2016 Subaru STi, which features an all-billet EJ 2.5L engine, was built to showcase what Kaiju Motorsports is capable of. Not only does it look great, but all expectation is that it performs well too. Check it out!

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There’s always a lot to look at during the PRI Show given the countless cool parts, machines and engines to draw your attention. One car and engine bay that made me turn my head every time I passed it was Kaiju Motorsports’ 2016 STi Subaru with an all-billet EJ 2.5L engine inside. After seeing the Subaru a few times, I finally got the chance to speak with Kaiju Motorsports owner Brian Camacho about his shop and the Subaru, and it was well worth the chat.

Kaiju Motorsports is located in Henderson, NV, and specializes in JDM and imports engine work, but mainly Subaru.

Kaiju Motorsports Subaru STi

“Subarus are our go-to vehicle,” Camacho says. “That’s our heart and soul you could say. We really know the Subarus in and out. We built this car to showcase what we can do as a shop.”

Initially, the 2016 STi belonged to Brian’s office manager who bought it brand new. It came to a point where he was ready to part ways with the car, but rather than sell it, Brian saw it as an opportunity to turn it into a shop race car.

Kaiju Motorsports Subaru STi EJ engine

“We did custom graphics, 15” slicks and custom work on the fenders and hood as well,” Camacho says. “A lot of our work focuses on the engine, transmission, drivetrain, and suspension. The engine is still a 2.5L block, like what comes in the car from Subaru, but we went with a new, billet EJ 2.5L block.

“The short block came out of Australia and then IAG Performance took it, and they threw in some Darton sleeves and assembled the whole rotating assembly. Then, we paired it up with IAG Stage 5 cylinder heads, which are CNC ported and have Ferrea dual valve springs and 1mm oversized Ferrea valves on it, as well as GSC bronze valve guides. We got Brian Crower Stage 3 cams on it, and what we did at our shop, we took the cylinder block, we took the cylinder heads, and assembled the engine.”

EJ 2.5L Subaru engine

As mentioned, IAG Performance spec’d the rotating assembly, which meant a billet crank, custom rods and custom JE pistons. Brian says IAG also machined the billet block for fire rings, which help seal the block to the cylinder head, along with 14mm ARP studs. The BC Stage 3 cams are 280 duration on both the intake and exhaust.

We also mentioned that this engine bay turned some heads throughout the PRI week, and for very good reason. Not only is the car cool and the engine itself cool, but the piping for the intake and turbo really sets the whole combo off thanks to the use of titanium.

billet EJ 2.5L Subaru engine

“The turbo kit is a twin-scroll turbo manifold mated to a Garrett G42-1200 compact turbo,” he says. “From there, we took the car over to Jesse at JDL Auto in Phoenix, and he killed it with the fabrication. He used a Hypertune clamps, Ticon titanium piping and just welded it all up to perfection. He did all our intercooler piping too. He took a CSF Magnum intercooler core and made a custom intercooler, and modified our cooling system and the CSF radiator. Then, it’s got a 4” turbo back exhaust with the titanium muffler on the back. The titanium is definitely one of the things that make people stop and really pay attention to the car.”

At PRI, the STi was parked in the Exedy booth because the Subaru also features an Exedy triple-disc clutch, which Brian says is holding up the power really well.

billet EJ 2.5L Subaru engine

“We’re pushing a little over 1,000 horsepower on this engine and 700 lb.-ft. of torque,” he says. “This clutch is rated for around 750 torque and it’s holding it well. This Subaru was built to showcase all our work, but it’s very important for me to perform as well as looking really good. The car is used for drag racing.”

Helping the billet EJ 2.5L Subaru engine do its thing is a MoTeC M150 ECU and a MoTeC C127 dash to display all the right data.

Subaru STi with a billet EJ 2.5L engine

“The goal was 1,000 horsepower, so we hit that expectation,” Camacho says. “Now, as long as we could get into low 9s with the car, I’d be happy with that. If we break the 8s – amazing. But, the goal is 9s.”

Engine of the Week is sponsored by PennGrade1Elring – Das Original and NPW Companies. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].

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