Engine Upgrade from EJ253 to new FB25B Possible?

[fan23]

Hello i currently own a 2010 subaru legacy 2.5i and I wanted to know if anyone here might have tried swapping their engines and had any success. Also the engine in my car has SOHC and was wondering if fitting a turbo will show a any significant boost.

[AdventureSubaru]

What's the advantage? You've already got the more reliable motor without the oil consumption issues of the FB motor.

 

These motors don't historically do well on turbo additions. If you want more power, I'd be looking to get into one with an EZ36

[1 Lucky Texan]

people have done all kinds of swaps - probably 'easier' (this is a relative term, it won't be 'easy') to swap in engine and probably driveline gear from a wrecked WRX.

 

over at NASIOC I'd bet you could find threads on a similar swap.

 

you can do almost anything with enough $$$$$ - cardoc SUPERcharged a 6 cyl. Outback!

 

you just need to pick the path that best fits your budget, mechanical ability, tolerance for being without your car and dealing with a lot of details - and your goal.

Edited September 22, 2015 by 1 Lucky Texan

[idosubaru]

Not worth it.   Sell the vehicle and buy what you want - FB25 or turbo engine or H6.

 

A cheap/ghetto $2,000 turbo install will probably grenade your engine in 6 months to 2 years.  Not what most people want.

 

If you want it done right - you're talking a lot more money and you might as well go back to my original suggestion - sell it and get what you want.

 

I'd charge (if i charged people to work on cars, which I don't) at least $10,000 I'd  think to do that swap...probably a lot more.

Edited September 22, 2015 by grossgary

[Bushwick]

Turboing an engine in general won't grenade it IF it's done correctly. Biggest mistake would be NOT getting it tuned, running low power fuel pump, undersized injectors, leaning it out, etc. I'm not a fan of Chinese turbos at all. They use inferior metals from bearings to exhaust housings, and their balancing of the CHRA is very questionable. 

 

I've had good luck with Garrett turbos and have rebuilt my own, even upgrading the entire cold housing a GT28 style and upgrading from a tiny 52mm to a 64mm you typically find on the GT2860 turbos, to adding a 360 degree thrust plate which prevent the weak factory thrust washer failure like I experienced on my high mileage factory unit. ONLY thing I didn't do myself was the balancing. I think I had $500 into it (new GT28 style cold housing, new exhaust wheel/shaft, new cold wheel, new bearings and c-clips,balancing, etc.) after the factory turbo cracked the lip on the thrust bearing, allowing the shaft to walk laterally and ultimately clip itself into the housing. Talking my Saab here which was factory turbo'd to begin with, so it was just a matter of getting it to physically FIT w/o getting an expensive aftermarket exhaust manifold that angled the turbo outward more, plus reflashing a second ECM (which isn't an option with Subaru so you need a piggy back unit or aftermarket unit).

 

If you want more power, go the NA EZ36 route. They make around 256 hp (IIRC) and are a direct fit to the Subaru trans. That's a 120hp+ more than a standard EJ22 AND you don't have to mess with turbo BS like intake ducting, FMIC, custom exhaust with at LEAST a 4" race cat (for a 6 cyl with a single turbo) or you'll experience extreme lag as it won't spool up as quickly as it needs to; your EGT will be higher, and ultimate flow will get restricted limiting hp.

 

What people often don't realize is "peak" hp means absolutely ZERO. For a daily driver with pep, you want as much torque as you can get, as early as possible and hope it holds it to redline and try and at least have as much, if not more hp. With that said, I'd take 44 hp hit with an EZ36 over a 300 hp STi engine any day of the week. Mighty Car Mods (google "Gramps" from Youtube) 1st did a mid 90's Legacy Wagon with an EZ36 then turbo'd it, before transferring the drivetrain over to a newer body style after the car got rained out when the windows were out (they were prepping it for a repaint) and the new variant is called "Super Gramps". Watch the earlier "Gramps" videos to get an idea of what's involved with JUST the EZ36 transplant and ignore the turboing aspect. If you kept it NA and aren't constantly racing it or beating the spoob out of it, you could probably leave the factory trans and rear alone until you have the $$$/time to upgrade to say STi trans/rear. If your car has an auto, it's a MUST to add a trans cooler with a small 8" - 10" electric fan (preferably thermostat controlled) as it'll help the trans cope and last longer. Fresh fluid every 30k-60k miles depending on age and abuse would be smart too. When the engine is out, DRAIN the torque converter and refill will best Subaru fluid you can afford.

 

I think if you want more power and early pep, the EZ36 is a great option. You'd the ecm, the fuel pump, and some effort to get it working with your car, but it's 100% doable. I'm seriously considering this with my 95' Legacy at some point (minus a turbo) and getting fresh paint with nicer rims just to have a different, clean, and quicker daily driver.