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Old 02-10-2004, 01:05 AM   #1
d00f
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Default EZ30 H6 turbo???

Ok, first of all I'm definitely crazy. Second of all I don't need to know what people think this motor will do to the handling.

I'm interested in turboing an H6 motor and dropping it into a GC8. I'm sure the transmission won't last very long so I think ultimately it would need a 6MT.

Long before that I'm considering selling off my STi engine/tranny and doing this as it's something completely different and could be an absolute beast. Here is what I think...

Obtain the EZ30 from a euro/jap spec car. Reason being better heads. Spend some time giving them a good port and polish. If practical, convert the valvetrain to shim under bucket.

Replace rods and pistons. Look at closing the deck but really I think re-sleeving the whole thing may be a better choice for the given power output.

Rip out the stock wiring and ECU - replace with a haltech. Rework the fuel system with better rails, FPR, pump and injectors.

Get a really strong clutch. Fabricate an engine cradle or maybe rework a legacy turbo/wrx/sti crossmember to allow an up-pipe. Fabricate some headers. Mount a large-assed turbo and TIG up another freightliner FMIC.

Target power output: 700hp.

Estimated cost: $20k CAD.
Here is an approx breakdown:
Fuel system $1k
Clutch $1k
Motor $5k
Rods & Pistons $3k
Resleeving block + studs etc $5k
Engine management $2k
Misc costs (parts, materials to make the exhaust, intercooler piping, perhaps STi shim under bucket parts, possible cam regrinding etc etc etc... $3k
Turbo (big-assed garrett GT) $2k

Just to give you an idea my current project is making an AWD 1.8T VW rabbit from a rabbit and a rolled audi. So this is consistant with my crazy scale.

Thoughts anyone?

-Michael
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Old 02-10-2004, 11:13 AM   #2
Tats
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I could have sworn this was covered b4. But I can't seem to find it with a search.


Tats.
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Old 02-10-2004, 11:38 AM   #3
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I spent a good 1/2 hour searching before writing up the post. Couldn't find anything. Apparently there was a guy in australia who did this swap and extracted 800hp from it. I spent some time playing with google and anders was the only swap I could find and his is NA.

I'm a man of many plans but less time. My Impreza has a squished nose so I'm not going to be driving it for a while. I'm just contemplating selling off the STi motor and going for some retarded amounts of horsepower.

-Michael
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Old 02-10-2004, 01:20 PM   #4
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Yeah, it was covered recently, but I don't think any real conclusions came from the previous discussion. I've been looking at the feasibility of adding a turbo to an EG33 motor, and based on my research I see no reason why an EZ30 can't be turboed at the level you are considering, but my feeling is that you are underestimating the cost.

You may want to give some thought to a 5MT with STi RA gears. The 6MTs are starting to show that they are not bullet proof either.
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Old 02-10-2004, 04:29 PM   #5
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About 2 years ago, when I had my SVX, I did a FAT turbo kit on it. It made decent power, but nothing like the 2.5 built did. The major problem, much like Chuck D. found out, there is NO aftermarket support for the H6 motor, either the EZ33 or the EZ30.
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Old 02-10-2004, 08:30 PM   #6
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I dont see any reason why this wont work.

I mean, basically you just need to get the EZ30 to run (get the EZ30R!!!) but you will probably need like a 6-speed at least for this, if not a HEAVILY reinforced 5-speed.

Then you just need a ghetto turbo kit with a huge turbo, custom piping, and some good engine management (probably just a link would surfice)

I wouldnt even bother with engine internals (especially since I dont even know if any exist)
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Old 02-11-2004, 08:44 AM   #7
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The ghetto turbo kit part is really the easy part. I've successfully made a number of those in my spare time. I think one of the biggest challenges is reworking the ends to make shoving that amount of air realistic. From what I hear the EZ30 heads are not exactly optimal.

There are lots of companies around who make custom internals and such so I'm not exactly expecting to buy most of these parts off the shelf anyway. I can't see the 5MT ever holding that amount of torque. It's been said that the 6MT is good for 600-800hp. Remains to be seen and I haven't really done a lot of research on it yet - people's claims and opinions are not always based on anything but hersay.

-Michael
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Old 02-11-2004, 01:01 PM   #8
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Ok, turbos require good exhaust flow. A total of 2 exhaust ports for a 6 cylinder is not good exhaust flow. Go buy a ver 7 or 8 motor and see what real power is all about. I built a ver 7 motor with an EJ257 block and 20 G turbo. Nothing can catch that car. It's pretty satisfying dumping the clutch at 5000 rpm using the 6 speed. Burns right through 1st and 2nd gears.
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Old 02-11-2004, 03:55 PM   #9
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Quote:
Originally posted by d00f
From what I hear the EZ30 heads are not exactly optimal.
The EZ30 heads suck, but like I said, shoot for the EZ30-R which has awesome heads
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Old 02-13-2004, 01:59 PM   #10
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There seem to be a large number of cars starting with the EJ257 block and sticking on a pair of JDM STi heads. I have an EJ20K block and heads in my basement. That would probably be more cost effective but I'd still prefer to do something different.

The 6 port heads EZ30-R are the ones I had in mind. I see that next year's legacy comes with a 3.0l and makes 250bhp. I guess I'll just have to wait for the first one to be rolled.

-Michael
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Old 02-13-2004, 04:20 PM   #11
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The biigest problem you'll run into is the fact that the EG33 uses the wrx bore, so pistons are readily available. The EZ30 has a bore that isn't compatable with any of the factory turbo cars, so custom piston will have to be built. If your truely going to do everything you listed and are willing to spend that kind of money it could definitly be done.

The only problem I see is the supporting components. If this is a daily driver at 700hp you'll probably have some reliability issues. Supra and Z cars make that kind of hourse power, but the trannys were design to take elevated power levels. Subaru on a whole doesn't.

Good luck and keep us posted.
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Old 02-17-2004, 11:49 AM   #12
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I think you may have fun with the funky new variable valve lift cam system on the 3l.

Also, I would give serious thought to building up a twin turbo setup rather than going for one big turbo. IIRC, each bank will fire in an evenly spaced manner, so each turbo would be fed nice well spaced exhaust pulses. Size the turbos correctly and you should get better response and better power than a big single turbo setup.

A friend of mine (Pat on the 22b bbs) is building up a twin turbo EG33 project. This is going to be very... interesting.
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Old 03-10-2004, 01:56 AM   #13
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Why dosent japan like 6 cylinders? or to better word that, why dont they import more to the US? We are so unloved.

I would love to see how this comes out.
IF your looking at that type money, why not look into a hybrid tranny?
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Old 03-10-2004, 08:05 AM   #14
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I think a 6MT would be fine. I wasn't looking at twin turbo because of the packaging limitations. In a legacy chassis they would fit. In an Impreza, that would be fun not only to fit them in there but also to work on the car.

-Michael
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Old 03-13-2004, 11:41 PM   #15
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I dont know much about H6 engines, but the sole fact of having 6 exhaust ports vs 4 to push a turbo will make it spool up much faster, allowing for easy twin setup, or a single large one (naturally easier config)
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Old 03-17-2004, 02:23 AM   #16
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might try searching the conversions forum for some info on swaping the motor into your car, but turboing it will be hard to find info on. and i dont think there will be very much room after putting that motor in.
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Old 03-18-2004, 08:22 PM   #17
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Let me know when you plan on selling the STi engine/tranny

Jiffy
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Old 11-15-2017, 11:36 AM   #18
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Default Ej25 or Eg33, not ez30

Big issue here for you. I own a 2008 l.l.bean wagon with this motor and its awesome, ive got 180k miles on it. These motors were designed to fit in the same space as the ej25, in fact they are just a hair over an inch longer despite having 2 more whole cylinders. To get this engine packaged in such a small space they made the journals on the crank much narrower. Like 25% narrower than ej25 ones. Supposedly this makes the crank and block very fragile and does not make this an affordable build over 300ft lbs of torque. You will need to get a custom billet crank and better sleeves and crank bearing reinforcements to achieve over 400hp. You already mentioned rods which due to the journal size you will have to go titanium to achieve anything huge. This usually runs $20k+ USD alone in just parts not including putting it together.

Second issue is they have a different Bell housing pattern and flywheel since they only ever came with the 5speed auto. So all that will have to be custom as well.

Had a buddy cut his hood up and put a 7psi whipple blower on his. Motor threw a rod before his next oil change.

If you want to make big power spend the time and money on something else. Eg33 or ej25 you can build either of these to 1100hp for the price it would take you to get an ez30 to 550hp.

Only worthwhile mod you can do to the ez30 is upgrade the whole valve train and get it to rev to 8k or maybe 9k rpm. Everything else that can be done already has. If you get the 2007 to 2009 d version (some people call them r though Subaru calls them d) then porsche has already ported and flowed the heads so there wont be much room for improvement there.

Also as a side note I believe you can get a little more stroke if you do get a new billet crank. Probably worth it for that little extra torque and displacement.
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Old 11-27-2017, 05:46 PM   #19
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way to revive a 13yr-old thread.

xcceleration.com has H6 boost parts (closed deck block, heads, etc).
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Old 12-15-2020, 04:06 AM   #20
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Quote:
Originally Posted by Lord_hyren View Post
Second issue is they have a different Bell housing pattern and flywheel since they only ever came with the 5speed auto. So all that will have to be custom as well.
At least for the 01-04 (Phase 1) EZ30 this is simply not true, 5MT's and 6MT's bolt right up. The flywheel bolts right to the crank, with the longer flywheel bolts of course.

I believe the 05+ has the same bellhousing, I know people have done manual swaps with them.

Don't steal an EG33 from an SVX!
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