+200 awhp on E85 over 93 - 2019 Subaru WRX STI with GermanTech Motorworks built EJ257 hits 757 awhp on E85 flex fuel

[Sticky]

The Subaru EJ series of engines certainly offers a long and storied history of tuning results. Well before everyone went turbo Japanese tuners were getting monster output out of the boxer four-cylinder literally decades ago. It continues to impress well into 2021.

This is a 2019 Subaru WRX STI with a built motor from GermanTech Motorworks. Johnson Tuning did the software work through a Cobb Accessport V3.

A very nice mod list:

IAG Performance IAG900 Long Block
GSC Power-Division 272 Cams
Extreme Turbo Systems Rotated Kit w/ GTX3582R Gen 2 Turbo
Extreme Turbo Systems Header
Injector Dynamics ID1700s
2 Walbro 450 w/ I-Wire Wiring
Process West Intake Manifold
Extreme Turbo Systems 4” Intercooler
Flex Fuel Kit
Johnson Tuning Tuned w/ COBB Tuning Accessport V3

And monster power from the 2.5 liter motor:

553 awhp 415 wtq on 93 octane
757 awhp 583 wtq on E85

If someone says E85 does not make a difference over pump fuel, show them this graph. This STI is making over 200 more horsepower at all four wheels on ethanol over pump 93 octane.

Not that the car is any slouch on pump gas with 553 all wheel horsepower. Flex fuel ability provides quite the bonus and versatility.

Awesome build!

[93siro]

What’s even more impressive is the fact that Subaru is too lazy to give us anything beside this almost 2 decade old engine!

[Sticky]

What’s even more impressive is the fact that Subaru is too lazy to give us anything beside this almost 2 decade old engine!

If it ain't broke...

[93siro]

If it ain't broke...

2004 STi: 300hp 2004 Ferrari 360: 400hp
2021 STi: 310hp 2021 Ferrari F8: 700hp

STi should have had +500hp with that formula.

That’s the problem with Subi and Mitsubishi. They both let go of improving the cars that basically owned the tuning scene back in the day in pursuit of terrible econoboxes that led Mitsubishi to the misery it is in now. They took things for granted instead of raising the bar.

[Sticky]

2004 STi: 300hp 2004 Ferrari 360: 400hp
2021 STi: 310hp 2021 Ferrari F8: 700hp

STi should have had +500hp with that formula.

That's an absurd formula as an STI is not a Ferrari and secondly the 360 is naturally aspirated and the F8 is a larger twin turbo V8. The comparison makes no sense.

It would be like saying the F8 should hav 415 horsepower based on the inverse.

[crapinternet]

If it ain't broke...

Well it breaks when the head gasket starts to weep, or cyl 4 loses a ringland because it got too hot from a flaw in the cooling system, or any turbo is horribly laggy because of the exhaust manifold setup and it not being twin turbo. So many reasons the EJ25 and STI's in general are trash.

Although, I think post 2017? they changed to a timing chain, instead of a timing belt.

[Sticky]

Well it breaks when the head gasket starts to weep, or cyl 4 loses a ringland because it got too hot from a flaw in the cooling system, or any turbo is horribly laggy because of the exhaust manifold setup and it not being twin turbo. So many reasons the EJ25 and STI's in general are trash.

Although, I think post 2017? they changed to a timing chain, instead of a timing belt.

Sure, it has flaws but it was there in the early Japanese turbo tuning days and allowed the Japanese to circumvent the stupid hp cap.

It would be nice for Subaru to bring the heat with the next STI but whether they do or not the EJ cemented its place in history.

[BLKROKT]

That’s the problem with Subi and Mitsubishi. They both let go of improving the cars that basically owned the tuning scene back in the day in pursuit of terrible econoboxes that led Mitsubishi to the misery it is in now. They took things for granted instead of raising the bar.

THIS is so true. Look at what’s become of the Eclipse. They lost the plot, it’s some sort of ugly crossover now. The enthusiast community around the Mitsubishi-based DSM cars was second to none.

But you can still sub the Evo in for DSM as a proxy, the engine is basically the same. And about the same pathetic progression as Subaru over a 10yr longer period.