Scubi questions, Motor questions Options

[r_towle]

So, whats the list of decent motors for a subaru swap?
What is the price range nowadays?
If going down this road...is there a motor that can be upgraded to the STI motor over time???

Ideally I would like to figure out if a 2.5 liter legacy motor (or whatever) can have new cams and special head work and become an STI...etc...

Rich

[VaccaRabite]

If you want to eventually go up to a STi motor, you are going to be spending a little coin.

The ej2.0t out of the WRX up to 2005can be made to produce STi power pretty easily, though. Its also cheaper.

Taking a 2.5T out of a forrester XT or a 06-current WRX can be built to STi spec.

There is a TON of after market for the 2.0t motor. The pre-2006 WRX is to the current crop of ricer tuners what the Honda Civic was to the previous one.

Zach

[r_towle]

If you want to eventually go up to a STi motor, you are going to be spending a little coin.

The ej2.0t out of the WRX up to 2005can be made to produce STi power pretty easily, though. Its also cheaper.

Taking a 2.5T out of a forrester XT or a 06-current WRX can be built to STi spec.

There is a TON of after market for the 2.0t motor. The pre-2006 WRX is to the current crop of ricer tuners what the Honda Civic was to the previous one.

Zach

So, the ej 2.0 turbo is the favorite motor?
Is this motor in anything besides the wrx?

Rich

[Todd Enlund]

I believe that the STi uses a different block... it has a semi-closed deck.

JDM twin turbo engines are cheap and plentiful, but I've heard that parts compatibility is not 100% with USDM stuff. Like Zach says, the WRX 2.0 engine can make STi power (and more), but probably not as reliably as the STi. Way cheaper though. I think you'd be lucky to get a good STi engine for much under $5k. WRX could probably be had for $1.5k. JDM stuff is in the $800 range.

I was looking into a Subie conversion before I decided to build a big Type IV. A well done Subie is not going to be as cheap as some of the numbers that people are throwing around.

[r_towle]

I am still confused...
The US WRX STI motor is not the same as the JDM WRX STI motor?

Explain the differences once again between the 2.0 WRX motor and the STI motor...
What is a semi closed deck? is the head difference or is the case closed off somehow?

Rich

[Todd Enlund]

I am still confused...
The US WRX STI motor is not the same as the JDM WRX STI motor?

Explain the differences once again between the 2.0 WRX motor and the STI motor...
What is a semi closed deck? is the head difference or is the case closed off somehow?

Rich

Nope... USDM and JDM engines are different. I can't give you specifics though... but I believe that the JDM STi is still 2.0 liters.

The standard Subie engine has cylinders that are free-standing in the water jacket (open deck). The semi-closed deck on the STi has webs that support the cylinders.

I found a pic:

http://www.grindstonemotorsports.com/tech/blockdesign.jpg

[budman5201]

Advice from my experience. (on 3rd subie conversion) This time around i am using a US spec 2.5 liter Naturally aspirated engine with free flow intake, free flow exhaust to an extent (dont want to lose too much torque) and delta 2000 grind cams. The stock 2.5 n/a is a blast, this one should be killer too. Yeah if you plan on turboing it later i would recommend going with a closed block due to the head gasket failure porblem when under boost. The STI motor has lower compression pistons so when under boost it wont detonate. But the standard 2.5 n/a motor can handle some boost to bring it up another 35 horsepower if needed in the future. (5 lbs or less boost) As long as you have a free standing computer like my setup (link computer) and you can monitor from your wideband o2 sensor at ALL rpms and loads (dynoed) then you should be fine. (ex. larger fuel injectors with turbo, programmable fuel going into cylinders,etc)

I'll release my dynoed numbers after this conversion....should be nice. (IMG:style_emoticons/default/popcorn[1].gif)

stay tuned should be done by end of august with this one!

[budman5201]

next subie conversion

[r_towle]

I am still confused...
The US WRX STI motor is not the same as the JDM WRX STI motor?

Explain the differences once again between the 2.0 WRX motor and the STI motor...
What is a semi closed deck? is the head difference or is the case closed off somehow?

Rich

Nope... USDM and JDM engines are different. I can't give you specifics though... but I believe that the JDM STi is still 2.0 liters.

The standard Subie engine has cylinders that are free-standing in the water jacket (open deck). The semi-closed deck on the STi has webs that support the cylinders.

I found a pic:

http://www.grindstonemotorsports.com/tech/blockdesign.jpg

Seems pretty self explainitory with that picture...
So, which motor has the closed deck...its the one I want.
And...
What is the base HP for these motors?
I dont want to re-invent the wheel. A US spec wrx turbo sounds like the place to start if I want to get into the super tuning level of fun...

Rich

[jimkelly]

http://www.renegadehybrids.com/914/Subie/Subie.html

and matt monson is one of our resident subaru experts

http://www.914world.com/bbs2/index.php?showuser=4562

[VaccaRabite]

And...
What is the base HP for these motors?
I dont want to re-invent the wheel. A US spec wrx turbo sounds like the place to start if I want to get into the super tuning level of fun...

Rich

US spec 2.0t was rated at 225 HP.
US spec 2.5 NA was rated at 165 hp
Both of these engines are cheap. The NA engine is surprisingly torquey, and is the way I would go if I was going to do it. Its also the motor that I know the best, as I drive one every day. It has been utterly faultless for 100K miles over 4 years. The only time it has failed was due to a dead battery.

US Spec STi motor is rated for 305.
I don't know what the 2.5t motors (new WRX) are rated for, but it is not much more then the 2.0t.

Zach

[DBCooper]

Unless you intend to get north of 350 horsepower there's not that much advantage to a closed over an open deck. There's a good description of all the Subaru chassis and engine codes here: http://www.toronto-subaru-club.com/forums/...ead.php?t=84585

EDIT: And more on the different engines: http://en.wikipedia.org/wiki/List_of_Subaru_engines

There is actually no official EJ20T engine designation, that's just shorthand for an EJ two liter engine with a turbo. The STI EJ207 engine (the first five digits of the engine number) is different than the EJ205 WRX motor because it has all forged internals, pistons, rods and crank, for higher stock boost and more horsepower (227 for the WRX stock, 300 for the STI). That means the STI engines are more rare, pretty highly sought after, and as a result more expensive. The non-STI EJ205 WRX engines are excellent and what most people use for performance conversions. No issues.

Once you get the cats and restrictive intake off the WRX engine, and hopefully onto a standalone ECU, you should get up around 300 horsepower without a lot of work. The WRX engines go for $1000 to $2500. Try to aim at a 2002 to 2005 motor, the sweet spot, but if you're going to do the work and tuning yourself any of the WRX motors will be pretty much as good. The advice I've gotten is that an aftermarket standalone ECU is the only way to go unless you're putting the motor into an older Subaru or other car that has to meet the smog visual check, when you'd want to use the OEM ECU.

If you want to be different and spend a little more the newer Japanese Domestic Market STI's have a similarly good 2.5 liter motor, the EJ257, but what really intrigues me are the NA 2.5 SOHC engines, which are all over the place and for under $1000 are cheap as chips. They're 165 hp stock, easier to install than a turbo, and nearly 200 hp with only exhaust and an ECU, which you'll do anyway to put them into a 914. That's the same non-turbo power as a much heavier and far more expensive 80's 911 Carrera motor, so not bad. But also take a look at the 2001-2004 EZ30 three liter flat six engines, which could be very cool. Also NA, 212 hp stock, 250 with better exhaust and induction, pretty much the same size as the four cylinder engines (less than one inch longer), and with a firing order that should produce an exhaust sound that would be very 911. These aren't the big old H6 3.3 SBX engines, they're much smaller, lighter, more modern and more powerful, the seeming perfect mate to the 914.

As info you'll see a lot of engines at wrecking yards (like www.car-part.com) that have broken cam sprockets from front collisions. The later engines are all interference, meaning that when the timing belt stopped in the collision there was almost certainly valve to piston contact. Usually the valves just bent and a new set of valves and guides will fix things up, but sometimes EVERYTHING gets mangled. So you take your chances with those engines. Luckily heads aren't that expensive or hard to find for any engines except the STI's, so a lot of times you can get an exceptional deal. Not always, though.

The folks at Small Car Performance are great and have all the little bits and pieces you'd need. They specialize in Subaru engines into Vanagons. The folks at Outfront Motorsports are similar, but they put the engines into sand rails, so they're more performance oriented. A lot of good practical performance info on their website, too. Both companies are knowledgeable and incredibly helpful. Good forums are Subbug (Subarus into VW's) and NAISOC (Imprezas).

[Todd Enlund]

I just remembered another consideration... the STi (and maybe some other newer cars) are drive-by-wire, which can be a PITA to adapt.

[Zaney]

Here ya go Rich!

STi engine on Evilbay

(IMG:style_emoticons/default/beerchug.gif)

(IMG:style_emoticons/default/driving.gif) Oh ya!

[DBCooper]

I just remembered another consideration... the STi (and maybe some other newer cars) are drive-by-wire, which can be a PITA to adapt.

True. Those are all after 2005, so stay with the older engines and you're fine. But even if you get a new engine you can just put on an earlier mechanical throttle body with a standalone ECU and you're good.

Then there's variable valve timing starting in about 2004 (depends on which engine) which is on-off, so easy to control with an aftermarket ECU. More complicated is variable lift (starting in 2006, also depending on which engine) which isn't linear and depends on a lot of different engine operating parameters. Evidently an upcoming version of the Link G3 ECU (in the next 60 days or so) will control that as well, but for right now you won't get the extra torque that the variable lift gives under 4000 RPM.

Those aren't really big obstacles though. If you get a chance at a reasonably priced and nearly new STI engine I'd grab it and gladly deal with the newer technology. In the meantime a nice WRX motor and a Renegade kit would give you all the thrills you're likely to need.

[r_towle]

It looks like a turn key WRX STI motor is the place to start.
Turn key, properly shopped would be 5k from what I am seeing...yes or no? This would include the turbo etc.

Rich

[Zaney]

(IMG:style_emoticons/default/hijacked.gif) I am now in a dilemma in chosing a Suby engine myself. I thought I wanted to go the 2.5 Sti turboed with a Suby 5 speed tranny but, now I want to find out more about the ER33 SVX engine (6 cylinder N/A engine). Smallcar.com has a conversion kit for this engine to mate it to a manual 5 speed tranny (stock is an auto).

Someone chime in on any pros and cons with this option verses a 4 cylinder turbo engine.

This may provide Rich with another option for a conversion as well. (IMG:style_emoticons/default/beer.gif)

Thanks!

[VaccaRabite]

I thought I wanted to go the 2.5 Sti turboed with a Suby 5 speed tranny but, now I want to find out more about the ER33 SVX engine (6 cylinder N/A engine).

Someone chime in on any pros and cons with this option verses a 4 cylinder turbo engine.

SVX is fine if you don't want to build it. It does not have anywhere near the after market support that the Impreza line of engines have. It was also designed for an auto tranny.

Personal preference is that i would not use it, even though it is supposed to be a great engine. They are going to be older then many other Suby engines, parts are harder to get, and it weighs more.

Zach

[ninefourteener]

2002-2005 WRX - 2.0L, 227 HP, TD04 turbo

2006-2007 WRX - 2.5L, 230 HP, TD04 turbo) much better torque though. They utilize drive-by-wire throttle though, which causes complications when doing a transplant.

2004-2007 STI - 2.5 L, 300 HP, VF39 turbo (VF43 twin scroll turbo in 2007) HP is primarily due to larger turbo only. The 2.5 Blocks are the same as the 06-07 WRXs, however, the STI internals are stronger (several forged components).

The 2.0s can be made to produce well over stock STI power levels safely with turbo upgrades, but keep in mind they will also require larger injectors and a fuel pump to support it. STI "pink" injectors are a popular upgrade.

The 2.5 WRX engines will support nearly 400hp on the stock "blue" injectors

The 2.0 WRX engines can be safely built up to 400 hp without stronger internals

The 2.5 WRX engines will support up to 450hp on the stock internals safely.

The 2.5 STI engines can support over 500hp on the stock internals.

2.0 engines on ebay sell for $2500-ish
2.5 (WRX) engines sell for $3000-$3500ish
2.5 (STI) engines start at $5000, and go up to $8000

Obviously this is vague, generic info, but it's a start. The 2.0 WRX engines are a very reasonable choice if you're on a budget, and will support lots of HP, especially for a 914.

Keep in mind, with ALL of these choices, you will need to be properly tuned, and have some kind of computer controlled engine management system.

Added: To answer a few more questions I read above, The (almost) entire Subaru line uses H-4, 2.5L engines now. The Tribeca and some of the Outbacks use a non-turbo H-6. The Legacy and outback utilze a different intake/exhaust/intercooler setup than the Impreza line though.

The Forester uses EXACTLY the same engine/transmission setup as the Impreza line.

Factory non-turbo Subarus are great, but turbocharging them ends up to be more expensive than just buying a factory turbocharged engine. Not to mention, the internals cannot support NEARLY as much boost as the factory turbo engines.

Added again: The WRX and STI engines, of all years, are essentially legos.... you can swap parts left and right, and they all fit (except the injectors)..... great for planning upgrades, because you never need to change the intake / exhaust, etc.... they all bolt directly on to one another.

Example, my 2006 WRX:
Stock - 230 hp
+ full 3-inch turboback exhaust with bellmouth downpipe - $500
+ Cobb Accessport hand held tuner - $700
+ Used VF39 (stock STI) turbo w/ 1500 miles - $450
+ Used STI intercooler - $250
+ 2 hours on Cobb's dyno - $400
= 305 AWHP (385 @ the crank), mid 12-sec 1/4 mile times.

Thats it..... nothing else was required... it all bolted right on or plugged right in..... and it's a SAFE, dailly driver. The 2 hours on Cobb's dyno was only to squeeze a few more HP out of my injectors (I was at 362 hp before the dynotune)

[WRX914]

I bought my EJ20 for $2k complete. 2 years later, I had a cooling issue which led me to purchase a OEM Subaru shortblock EJ2.5 STI shortblock for $1740.00 DELIVERED to my door. The swaping of components is a breeze added 75 more ponies!

Don't forget... it is a BRAND NEW block direct from Suby, and it only weighs about 70lbs!!!