Jump to content
Ultimate Subaru Message Board

Want to turbo an N/A 2005 Subaru Legacy 3.0r


Recommended Posts

I want to turbo my 2005 Subaru Legacy 3.0r. I just want to know if it is worth it and wether it is possible. I was hoping that i might be able to use an sti set up and work off that.  I only want to put out about 10-12 Psi and hoping that it will increase the  performance quite a bit. I would also like to know roughly how much it might cost to manufacture some of the custom parts and what might be needed to do this conversion.

Link to comment
Share on other sites

If you want a setup like that, I would recommend just buying an sti. There are several upgrades needed on a stock engine before installing a turbo to prepare the engine for the added torque a turbo produces. I had a kid walk into my shop a few months ago wondering the same thing told him the same info and he didn't listen and sure enough his car showed up at my shop on a tow truck less than a week later with a blown moter.

Link to comment
Share on other sites

Thing is with a 3.0 it already has fairly high compression. I'd probably want a lower compression set of pistons before dumping a turbo on it. Second issue is engine management. I'm not sure if the 2005 computer can be tuned or not to support a turbo.

The whole process would be a lot of work and cost a lot of money.... Probably quite a lot of money. BUT it would be totally awesome. If you have the time and money to work on this project... I'm excited to see videos of it :)

Link to comment
Share on other sites

haha! well, i like making up numbers and seeing what they say.

i did say get a quote since that would quantify his local resources, that's the big ambiguity here - who does he know or have at his disposal to do the work?

i'm inferring high labor costs since it sounds like he's not doing the work...

 

Raptor kit is $5k. (+ install)

$2.5k STi engine and $2.5k install/parts = $5k

RAM quoted $2,400 for a low compression H6 XT6 block rebuild. $2.5k for install/additional parts/labor

 

As a very rough $/hp order of magnitude estimate -  $5k seems a good starting point for him to start talking...."wow, that's better than i thought - what exactly does that mean.....or.....after i change my pants, how can I put $500 into this rusted beat up offroading POS?"  

 

custom exhaust, turbo charger and parts + install is going to be 4 digits

couple grand for aftermarket ECU and tuning is going to be 4 digits

Rebuilding the lower end with turbo pistons, wide band O2, EGT sensors, gauges....that's a few thousand more.

Link to comment
Share on other sites

  • 1 month later...

You're far better off to supercharge it than to try to do everything necessary to convert it to a turbo.  Supercharging is 6-8 psi but it has no lag at all.  Turbo has lag but it can push upwards of 16 psi + and unless you reduce compression, you'll be blowing the heads right off of it. 

 

Nonetheless, if you're feeling froggy and want to jump....here's a link to read about it and you can find more if you google "Subaru 6 cylinder turbocharge kit"

 

http://www.subaruoutback.org/forums/65-parts-accessories-performance/3607-turbo-6-cylinder-boxer-sick.html

Link to comment
Share on other sites

  • 9 months later...

Thanks heaps for the info guys, I'm scraping Together as much info as I can. I've found a page where Perrin made a turboed h6 for sema and the results were promising (with a lot of work). As well as them I also saw that mcm turboed a 3.6l Tribeca motor and stuck the 6 speed manual to it in a legacy wagon. They only pushed out around 8-10 psi running on e85 fuel. The nick named SUPER GRAMPS put out around the 275kw to the wheels which would be more than enough for what I want. My biggest issue now however is the compression on an open deck engine like mine... What would be the best way to try get past this issue? Sleeve? Custom closed deck modification? I was thinking about dropping the compression ratio or the supercharger you spoke about. I'm leaning towards the supercharger simply for the no lag factor.. But I really want something a bit different than a bolt on mod... Personally I think the H6 can do quite a bit more than they led on... But it will need a bit of money thrown at it.

Still spitballing even after this long, but doing some supporting mods while I decide

Cheers

Link to comment
Share on other sites

What would be the best way to try get past this issue?

 

Ask a local performance shop to build you an "XYZ" hp engine.

 

Or, how big and how much? Make that decision then you can answer questions.

 

Break everything down to "per cylinder" to simplify.

 

Read all the 4 cylinder builds and ball park everything by a proportional 3/2: (6 cylinders/4 cylinders = 3/2).

 

IE:

2005 an EJ25 makes 165hp.

divide by 2 and you get 41.25 hp per cylinder.

multiply by 3 and you get 247.5 hp....or....nearly identical to what your EZ30 makes

 

with that you can extrapolate lots of information about what you want, what others have done and what trigger points there are for various compression, hp, and boost numbers.

 

At XX compression you need...

At YY hp you need...

At ZZ boost you need....

 

and more...

Edited by grossgary
Link to comment
Share on other sites

Hopefully you have deep pockets as this is not a cheap endevor.

 

The Perrin built 3.0 turbo STI was a nightmare to tune and they never could get it tuned right. Had major issues with it before the owner gave up. It has good info to read but that's about it.

 

Your best bet would be the Raptor supercharger as it was specifically designed for the second generation 3.0

 

I've also had a couple second Gen 3.0s come in with cracks in the #3 combustion chamber that allows coolant to seep into the cylinder and cause a misfire.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...