Subaru Engine Conversion Wiki, Let's compile all the knowledge into one thread... Options

[charliew]

Exhaust System

- Headers

(IMG:http://www.914world.com/bbs2/uploads/post-4154-1249270963.jpg)



- Mufflers

(IMG:http://www.914world.com/bbs2/uploads/post-4154-1248752914.jpg)

Be real careful you have enough heigth on the turbo to drain the oil to the pan or you will pump oil out the exhaust and into the intake manifold and cooler.

[charliew]

Very interesting motor mount you added. Uses the stock bar/mounts? Im curious how the owner of that car likes that as with that power you would think you might need some better mounts.

That smallcar mount has been changed to work with the 914 bar by it's owner.
Smallcar puts subys in vanagons.

[dlo914]

Here's what our smallcar engine mount looks like after fabbing it up for 914 use.
(IMG:http://www.914world.com/bbs2/uploads/post-2697-1262148792.jpg)
(IMG:http://www.914world.com/bbs2/uploads/post-2697-1262148814.jpg)

There isn't much progress lately on our project, but here's our thread link:
http://www.914world.com/bbs2/index.php?showtopic=92942

[Britain Smith]

Thanks for the pic.

The one difference I see between the Small Car mount and the Outfront Mount is that the Outfront mount actually bolts to there adaptor plate.

-Britain

[Sleepin]

Not a whole lot to contribute here, but I wanted to thank you for getting all this info together Britain!

One thing to check is the clubNARP forum for Subies: http://z8.invisionfree.com/ClubNARP/index.php?showforum=20

Thanks again, this is very useful!

[JRust]

I'd like a link or someone who knows the subaru drivetrains to give a breakdown on the motors. Basically the HP in stock form & the benefits of each motor. REally considering a subaru swap at some point. Would like to keep an eye out for a good setup. I will hit up some different subaru forums. Figured this might be the place to have the breakdown for the motors though (IMG:style_emoticons/default/idea.gif)

[bfrymire]

I'd like a link or someone who knows the subaru drivetrains to give a breakdown on the motors. Basically the HP in stock form & the benefits of each motor. REally considering a subaru swap at some point. Would like to keep an eye out for a good setup. I will hit up some different subaru forums. Figured this might be the place to have the breakdown for the motors though (IMG:style_emoticons/default/idea.gif)

Wikipedia.org

http://en.wikipedia.org/wiki/List_of_Subaru_engines


RenegadeHybrids

Outfront motor sports

http://www.outfrontmotorsports.com/motor_matrix.htm

I am sure there are more.

-- brett

[AndyB]

Britain thanks for the work. Nice to see all of this in one location (IMG:style_emoticons/default/beerchug.gif)

[d914]

intersting site for older JDM motors

http://www.catherineandken.co.uk/sti/wrx.html

Tranny specs

http://www.catherineandken.co.uk/sti/trans.html

speed calc

http://www.catherineandken.co.uk/sti/tyres.html

I didnt check the early pages.. sorry if duplicate

from Vin plates

http://www.catherineandken.co.uk/sti/engine.html

[d914]

and my build thread..

http://www.914world.com/bbs2/index.php?sho...947&hl=epic

front mount turbo, engine cradle by BOB.... suby tranny, soon to be cable shift..

Been a long haul but moving again,

[NC_Colfax]

What is everyone using for electronics??

How do they interface with the 914??

[DukeTrout]

This is a late reply, but I thought I'd chime in.

I'm coming to the party as a Subaru guy with an extra EJ25 engine sitting in my garage, looking for a chassis.

Since you're in Oregon, you have a lot of great Subaru resources close to home. When you're ready to have the engine talk, I'd suggest Cobb Tuning Surgeline up in Tigard.

A stock EJ25 engine is good for just under 300 whp (AWD) and ~325 wtq with a medium-sized turbo and a good intercooler and exhaust setup. Running it 2WD drops the driveline loss from 24% to ~15%, so more like 325 whp. Tuning with E85 can also help, both in terms of torque and turbo spool.

A mildly built engine with forged pistons can put out 300-400 whp in an AWD Subie. It all depends on how big of a turbo you want to run and how much lag you can stand. Again, if you have the fuel pump and injectors to flow enough fuel, E85 can really be a great fuel for these engines, better than race gas.

For example, in my daily driver Legacy GT, with a tune for 92 octane pump I can get 290 whp with 310 wtq at 18 psi boost. With E85, the tuner can tune it for 21 psi boost, 310 whp and 350 ftlbs. The torque curve also shifts about 700 RPM to the left with E85, due to quicker spool.

I'm not sure what else it affects in a 914 build, but the Cobb AccessPort is the go-to ECU programmer for the Subaru folks. If you're keeping the Subaru ECU connected to the engine, the AP might be the way to go. I'm not sure what needs to be deactivated in the Subaru ECU to allow it to run just the engine (probably a lot) but it might be easier than building a tune from the ground up with an aftermarket ECU.

I'd like a link or someone who knows the subaru drivetrains to give a breakdown on the motors. Basically the HP in stock form & the benefits of each motor. REally considering a subaru swap at some point. Would like to keep an eye out for a good setup. I will hit up some different subaru forums. Figured this might be the place to have the breakdown for the motors though (IMG:style_emoticons/default/idea.gif)

[Britain Smith]

Hey Duke...here is my Subaru conversion thread. I have a dyno date in 2weeks at Cobb Surgeline.

http://www.914world.com/bbs2/index.php?act...=2&t=113579

[utah914]

Has anyone done heat with a suby swap?

[malaga_red75]

I have been going thru several of the threads regarding Subaru engine conversions to learn about the different ways people are performing the installation. From radiators to CV adaptors, there are several paths to take. Lets try to compile all that information into one thread. Anyone can contribute and I will take the information in the thread and update the top few posts with the details.

Here is a list of 914 Subaru related Threads:

The Project Anklebiter Build Thread

Suby-engined rustoration

Zaney's Suby Rustoration Adventure

PorSTi Project Thread

It's official, Subaru EJ25 progress thread

Subaru 6 Cylinder EZ30R Conversion

My 914 EZ30R Twin Turbo Conversion

914 SVX swap, subaru 3.3 conversion

914 Subaru EG33 engine and WRX transaxle conversion, Finally finishing up

Subaru Engine w/Boxster transaxle, Perfect fix for 914???

One of THE most in-depth subaru N/A conversion threads out there. I know I used this thread several, several times during my build.

Tony's Subaru Conversion Thread

[thenewwazoo]

(bloody hell those smilies to the left are distracting)

Here's some quick info regarding suby transmissions and clutch assemblies.

There are two main types of suby clutches - "push" and "pull". Relative to the stock configuration, a "push" clutch has the slave cylinder mounted on the engine side of the clutch fork and actuates toward the driveshaft end. The "pull" clutch has the slave cylinder mounted near the center of the transmission and actuates toward the engine. The type of clutch actuation is dictated by the combination of the flywheel, clutch, pressure plate, throwout bearing, clutch actuation fork, and the slave cylinder. All of these items must be matched in terms of fork actuation direction. A transmission can be converted from pull to push by flipping the pull slave cylinder and using a kit - some bellhousings may have bolt holes for using either type, but I don't believe this to be the case. Note that cable-actuated clutches actuate in the "push" direction.

So here's a quick cheat sheet for transmissions and clutch actuation direction. From the factory on cars sold in the USA,
1.8, 2.2L engines came with cable-actuated clutches (Impreza -'01, Legacy -99?)
2.5L non-turbo engines came with push-style hydraulic clutches (Legacy 96+, Impreza 98+, Forester all years)
2.0L turbo engines came with pull-style clutches (02-05)
2.5L turbo engines in the WRX came with push-style clutches (06-09)
2.5L turbo engines in the STi came with pull-style clutches (04+)

You cannot mix and match flywheels with clutches across these (e.g. no WRX clutch on an N/A flywheel, no push WRX clutch with a pull WRX flywheel, etc). You also cannot use an STi fw/clutch/pp in a non-STi bellhousing without some grinding, and you still must use a pull-style clutch fork actuation. Why does this matter? Two reason: power and packaging.

Due to the proliferation of WRXes and the relative scarcity of high-power N/A cars, there are basically no cheap or livable options for N/A clutches that will handle real power. If you're not going to be making more than realistic power for a 2.5L N/A (say, about 200 lb-ft), you can use any clutch combination you want. If you are going make more power, you can either shell out BIG bucks ($800+) for an N/A clutch/fw/pp kit, or you can find a way to make a WRX or STi clutch work.

So why not just grab a WRX clutch/fw/pp and stick it on any old gearbox? The gearbox might not have the bosses required to mount a pull-style slave cylinder. Why not just use a WRX transmission? The pull-style clutch actuation mechanism is physically large, and it's on the top of the transmission, right where the 914 has lots of metal. The push clutch cylinder is smaller, lives closer to the engine where there's space, and can be more easily made to fit inside the 914 transmission tunnel without cutting. The solution, then, is simple - you need a WRX clutch with a push-style clutch actuator. Luckily, that's what Subaru moved to with the WRX in '06+. You can use a stock N/A slave cylinder and clutch fork with an 06+ WRX flywheel, clutch disk, pressure plate, and throwout bearing!

This matters because WRX boxes are expensive (easily twice the cost of an N/A box of the same year), rarer since the N/A transmissions have been around since the early '90s, and basically identical in terms of capability when used in a 914. 06+ WRX flywheels aren't terribly cheap yet, but prices are coming down all the time. '06+ transmissions, however, are still really expensive.

What this means is that, when you're doing shopping, you must consider the transmission, that transmission's clutch actuation direction, and then what flywheel/clutch/pp combos match that direction. You can work backwards or forwards, but they must necessarily follow in that direction unless you want a headache. (IMG:style_emoticons/default/smile.gif)

[DukeTrout]

Thanks for the link, Britain. I've been looking for the thread on your project. I've seen your 914 at the ORPCA AX events and heard about the project at Surgeline when I had my Legacy in for tuning. I'm very curious to see it hit the road.

Jay

Hey Duke...here is my Subaru conversion thread. I have a dyno date in 2weeks at Cobb Surgeline.

http://www.914world.com/bbs2/index.php?act...=2&t=113579

[sawtooth]

Something that may be useful for guys considering a suby transmission or have a conversion already...

I was trying to resolve an issue with my suby trans where I could hear a bearing noise coming from the tail near 5th gear. I started talking with Bremar about how to determine the correct oil level after doing the 2wd conversion. They said not to rely on the dipstick for oil level. They have seen problems where the suby trans gets used in a mid-engine setup and is mounted at a slightly different angle than in the original suby. The result can be a dry 5th gear which they have had to replace along with bearings. The solution is to tap a plug in the case in the tail section high enough to bath the gearset at the tail. When filling with oil, open the plug and fill until oil comes out the plug hole.

I did what they suggested in my suby trans, tapped a plug about 2-3 inches up from the bottom near 5th gear. I ended up with about 7 qts of oil which is almost double the suby specification. Doing this resolved the bearing noise which I now know was due to not enough oil in the trans.

[Britain Smith]

Thanks for the link, Britain. I've been looking for the thread on your project. I've seen your 914 at the ORPCA AX events and heard about the project at Surgeline when I had my Legacy in for tuning. I'm very curious to see it hit the road.

Jay

Hey Duke...here is my Subaru conversion thread. I have a dyno date in 2weeks at Cobb Surgeline.

http://www.914world.com/bbs2/index.php?act...=2&t=113579

Hey Duke...are you in the Portland/Hillsboro area? If you are nearby, you are welcome to come by anytime to check it out. I should have it running by this weekend or next week.

-Britain

[BIGKAT_83]

Something that may be useful for guys considering a suby transmission or have a conversion already...

I was trying to resolve an issue with my suby trans where I could hear a bearing noise coming from the tail near 5th gear. I started talking with Bremar about how to determine the correct oil level after doing the 2wd conversion. They said not to rely on the dipstick for oil level. They have seen problems where the suby trans gets used in a mid-engine setup and is mounted at a slightly different angle than in the original suby. The result can be a dry 5th gear which they have had to replace along with bearings. The solution is to tap a plug in the case in the tail section high enough to bath the gearset at the tail. When filling with oil, open the plug and fill until oil comes out the plug hole.

I did what they suggested in my suby trans, tapped a plug about 2-3 inches up from the bottom near 5th gear. I ended up with about 7 qts of oil which is almost double the suby specification. Doing this resolved the bearing noise which I now know was due to not enough oil in the trans.

Great info there sawtooth.... Thanks
Everyone doing a transaxle conversion should be awhare of this. In the stock Subaru the engine and transaxle sits at very different angle than it does when mounted in the 914.

Bob