Subaru Enthusiasts Car Club of the Sierras

Subaru Enthusiasts Car Club of the Sierras (https://www.seccs.org/forums/index.php)
-   Technical Chat (https://www.seccs.org/forums/forumdisplay.php?f=11)
-   -   Engine Question (https://www.seccs.org/forums/showthread.php?t=8236)

Arrows 2009-10-26 09:33 PM
Engine Question
 
Would a 06 WRX Turbo engine fit into an 04 STi?

Would any special modifications be required?

And if it would fit would there be any issues arising from using a WRX Turbo engine in an STi? (Just talking about daily driving, no racing of any sort)

Thanks.

(I'm a noob @ this stuff)

100_Percent_Juice 2009-10-26 10:08 PM
Physically it would fit in the engine compartment. Are you also swapping the ecu and transmission?

Arrows 2009-10-26 10:13 PM
Negative. I take it that would be required for it to work...

100_Percent_Juice 2009-10-26 10:25 PM
I think probably just the ECU but I have no experience in that area.

Arrows 2009-10-26 10:30 PM
Well shit.

I'm assuming dropping in a STi engine would be a piece of cake compared to trying to put the WRX engine in, right?

Know anyone who wants a WRX turbo engine with 36k on it? lol, back to square one...

100_Percent_Juice 2009-10-27 07:13 AM
I don't think an ECU is that expensive. Take a look on nasioc before you decide to scrap your project based on something I said.

sperry 2009-10-27 08:31 AM
The only thing different between an '06 WRX block and an '04 STi block are the heads. The STi has better flowing AVCS heads, the WRX does not. In fact, the short block (bottom end) even share the same part numbers IIRC. Of course the ancillary bits on the STi motor are a bit different with the WRX having a smaller turbo, smaller injectors, smaller intercooler... but none of that stuff is essentially different from the STi stuff.

You could probably even keep the '04 STi ECU if you are able to re-tune it for the smaller turbo/intercooler/injectors on the WRX motor. What's hard to do is use a WRX ECU to run an STi motor... there's no way to control the AVCS, but the other way around shouldn't be hard.

I'm afraid to ask why someone wants to put a WRX motor in an STi... did someone blow up their STi and need a cheap replacement?

100_Percent_Juice 2009-10-27 08:55 AM
An 06 has the same injectors as an sti so if he uses the sti turbo and intercooler it will probably be even easier than what you said, to get an easy tune.

sperry 2009-10-27 09:02 AM
Quote:
Originally Posted by 100_Percent_Juice (Post 141355)
An 06 has the same injectors as an sti so if he uses the sti turbo and intercooler it will probably be even easier than what you said, to get an easy tune.
'06 WRX's have side-feed '04 STi injectors?

Kevin M 2009-10-27 09:26 AM
I think Juice and Arrows are thinking too hard on this one.

If you have a broken STi, an the borkage is in the shortblock, then just put the WRX shortblock into the STi and call it good. If you have a problem in the STi head(s) then just get that fixed.

WRX06TR 2009-10-27 09:30 AM
06 WRX's do have AVCS, but I believe the STi heads to flow better. And the pistons are different, and the WRX has a slightly higher compression ratio. There is a big thread with all the part numbers and parts compared side by side, but I am having trouble opening NASIOC right now.

100_Percent_Juice 2009-10-27 09:31 AM
Quote:
Originally Posted by sperry (Post 141356)
'06 WRX's have side-feed '04 STi injectors?
Why would top feed or side feed matter to the ecu, I thought you were talking about size.

sperry 2009-10-27 09:35 AM
Quote:
Originally Posted by 100_Percent_Juice (Post 141364)
Why would top feed or side feed matter to the ecu, I thought you were talking about size.
Top-feed and side-feed injectors even of the same size likely have very different latencies which would make a big difference requiring tuning of the ECU.

100_Percent_Juice 2009-10-27 11:31 AM
Quote:
Originally Posted by sperry (Post 141365)
Top-feed and side-feed injectors even of the same size likely have very different latencies which would make a big difference requiring tuning of the ECU.
You are a revolving debate machine. You posted...

Quote:
Originally Posted by sperry (Post 141353)
the WRX having a smaller turbo, smaller injectors, smaller intercooler.
So when you said smaller you meant top feed?

100_Percent_Juice 2009-10-27 11:35 AM
Quote:
Originally Posted by Kevin M (Post 141362)
I think Juice and Arrows are thinking too hard on this one.

If you have a broken STi, an the borkage is in the shortblock, then just put the WRX shortblock into the STi and call it good. If you have a problem in the STi head(s) then just get that fixed.
You're right, pulling his sti engine and taking it apart and then taking apart his wrx engine and then rebuilding the sti engine with parts from the wrx engine would be way easier than just taking out the sti motor and putting the wrx motor in and getting it tuned.:rolleyes:

Arrows 2009-10-27 11:44 AM
Quote:
Originally Posted by sperry (Post 141353)
I'm afraid to ask why someone wants to put a WRX motor in an STi... did someone blow up their STi and need a cheap replacement?
Yep.


I had a list of the broken components on the STi engine, but my mechanic has it. I need to get a copy of that.

Although I do know one or more piston rods is broken, oil pump is broken, dont know the state of the short block on the STi.

I'll get that list ASAP.

Thanks for the ideas guys.

Kevin M 2009-10-27 12:34 PM
Quote:
Originally Posted by 100_Percent_Juice (Post 141373)
You're right, pulling his sti engine and taking it apart and then taking apart his wrx engine and then rebuilding the sti engine with parts from the wrx engine would be way easier than just taking out the sti motor and putting the wrx motor in and getting it tuned.:rolleyes:
What the hell is actually wrong with it anyway?

Kevin M 2009-10-27 12:36 PM
Quote:
Originally Posted by Arrows (Post 141374)
Yep.


I had a list of the broken components on the STi engine, but my mechanic has it. I need to get a copy of that.

Although I do know one or more piston rods is broken, oil pump is broken, dont know the state of the short block on the STi.

I'll get that list ASAP.

Thanks for the ideas guys.
Okay, that answers that I guess.

If the problems are all in the shortblock, then yes, you should tear it down and put the WRX shortblock into the STi. That way, you still have an STi when you're done, not some weird hacked hybrid that will never quite work right without a custom tune.

sperry 2009-10-27 01:24 PM
Quote:
Originally Posted by 100_Percent_Juice (Post 141372)
You are a revolving debate machine. You posted...



So when you said smaller you meant top feed?
I thought the injectors on the WRX were smaller *and* top feed vs. the side feed STi injectors. When you said they were the same, I though they might actually be literally the same, i.e. both side feed, which was news to me.

Either way, they'll need tuning to switch from one to the other.

Like Kevin said, the best way to fix an STi w/ a busted shortblock is to replace the shortblock and leave everything else alone.

Kevin M 2009-10-27 01:30 PM
'06+ WRX injectors are the same (or really, really close) to side-feed STi injectors. Since '04 STi engines use topfeeds, and are smaller than side feed STi injectors, they are not directly compatible with any WRX injectors. So Scott is right, you cannot plug-and-play between WRX and STi injectors unless both engines are '06+.

The only reasons not to simply plug the STi manifold/wiring/fueling on top of the WRX long block (to get around the fueling differences) are the differences in the head, which boil down to AVCS and cam profiles as I understand it. Downgrading an engine, or pieces of it, is just never a good idea.

ScottyS 2009-10-27 01:47 PM
:omg:

sperry 2009-10-27 01:58 PM
Quote:
Originally Posted by Kevin M (Post 141382)
'06+ WRX injectors are the same (or really, really close) to side-feed STi injectors. Since '04 STi engines use topfeeds, and are smaller than side feed STi injectors, they are not directly compatible with any WRX injectors. So Scott is right, you cannot plug-and-play between WRX and STi injectors unless both engines are '06+.

The only reasons not to simply plug the STi manifold/wiring/fueling on top of the WRX long block (to get around the fueling differences) are the differences in the head, which boil down to AVCS and cam profiles as I understand it. Downgrading an engine, or pieces of it, is just never a good idea.
I don't think any STi <'07 has top feed injectors. There's a reason you can't swap STi block/heads under a WRX intake manifold. The WRX top feeds interfere with the AVCS solenoids unless you've got a Perrin fuel rail that will allow the front injectors to be clocked 90deg. That's why the STi all used side feed injectors up until the fuel rail re-design in '07 (IIRC).

Kevin M 2009-10-27 02:56 PM
I thought the '04s had the old "STi pink" injectors, but I haven't really kept up on the Lego details the last few years to be honest. I know the WRX got sidefeeds in '06 with the 2.5, but I could easily be wrong about when the STi got them.

sperry 2009-10-27 03:07 PM
Quote:
Originally Posted by Kevin M (Post 141386)
I thought the '04s had the old "STi pink" injectors, but I haven't really kept up on the Lego details the last few years to be honest. I know the WRX got sidefeeds in '06 with the 2.5, but I could easily be wrong about when the STi got them.
Wait... so now we're back to the '06 WRX having exactly the same injectors as the '04 STi? :lol:

The STi never "got" side-feeds. It always had them, until recently when they switched to top-feeds. I didn't think any WRX's ever had side-feeds.

100_Percent_Juice 2009-10-27 03:31 PM
I think Scott and Kevin are thinking too hard on this one.

Arrows if you have a borked car, fix it.

sperry 2009-10-27 03:40 PM
Quote:
Originally Posted by 100_Percent_Juice (Post 141391)
I think Scott and Kevin are thinking too hard on this one.

Arrows if you have a borked car, fix it.
+1. If the shortblock is broken, replace it. No other parts needed, no tuning needed, no sorting out what works, etc.

The rest of this conversation is academic.

100_Percent_Juice 2009-10-27 03:46 PM
If academic= riddled with false information, this thread is blazingly academic.

sperry 2009-10-27 03:50 PM
Quote:
Originally Posted by 100_Percent_Juice (Post 141398)
If academic= riddled with false information, this thread is blazingly academic.
Where is this thread "riddled with false information"? I see a bunch of people trying to figure out what the facts are... you not being one of them.

How about you go find the list of what size and type injectors came on each turbo Impreza in the US from '02 to '09. I've been searching google and NASIOC and haven't been able to find anything reliable yet. But at least I'm looking rather than adding useless posts to this tech thread. Except for this post apparently. :unamused:

100_Percent_Juice 2009-10-27 04:51 PM
It's actually a sticky.
http://forums.nasioc.com/forums/show....php?t=1218460

I guess I was wrong saying false information, I should have said misinformation. And I don't see a bunch of people trying to find facts, I see 2 people trying to get their facts straight after making incorrect statements. The injectors were never an issue until I posted something contrary to what you believed to be true and instead of finding the facts and then coming back to the thread you decided to argue about top feed and side feed.

sperry 2009-10-27 05:14 PM
Well I guess in the future I'll refrain from asking you legitimate questions. I thought "'06 WRX's have side-feed '04 STi injectors?" was a pretty straightforward thing to ask when someone states the '06 WRX has "the same" injectors as an '04 STi and I was pretty sure that no WRX's ever had side-feeds. Sure I was wrong about the sizes, but the point I was making about needing tuning was still correct.

If you want to start pointing out misinformation, you can start with your post in the thread:

Quote:
Originally Posted by 100_Percent_Juice (Post 141355)
An 06 has the same injectors as an sti so if he uses the sti turbo and intercooler it will probably be even easier than what you said, to get an easy tune.
...because you would in fact need to change the tune for the different injector latencies between the '06 WRX and '04 STi injectors, even though they're both rated for similar flow (if you consider 535 the same as 560). So really, the "similarity" of the injectors makes nothing much easier since the latencies will have to be updated and the flows scaled.

So then... for reference:

All WRXs have top-feed injectors.
'02 to '05 are 420cc top-feeds, latencies: 2.79, 1.49, 0.98, 0.68, 0.38 (in Cobb AP voltage order)
'06+ are 560cc top-feeds, latencies: 4.70, 2.65, 1.73, 1.20, 0.99

Some STi's have side-feeds, some have top-feeds:
'04-'06 STi are 535cc side-feeds, latencies: 7.66, 2.69, 1.37, 1.05, 0.75
'07+ STi are 560cc top-feeds, (which I'm assuming are the same as the '06+ WRX injectors)

So, when attempting to swap an '06 WRX motor into an '04 STi, you're going to need to re-tune the ECU for the injectors, even if you re-use the STi's turbo and intercooler.

Kevin M 2009-10-27 05:22 PM
Quote:
Originally Posted by sperry (Post 141389)
Wait... so now we're back to the '06 WRX having exactly the same injectors as the '04 STi? :lol:

The STi never "got" side-feeds. It always had them, until recently when they switched to top-feeds. I didn't think any WRX's ever had side-feeds.
I thought '04 STis had the same injectors as the EJ207, but I could very well be wrong. Like I mentioned, it's been years since I really strained to keep up with what swaps where (other than older NA stuff).

Also, I thoguht the 2.5 liter WRXs had side-feeds, but I guess that was conjecture on hearing they were the same size as the STi injectors.

Kevin M 2009-10-27 05:26 PM
Also also, "WRX motor" would be shortblock and heads I would think. Manifolds, fueling, and wiring shouldn't be swapped if they don't have to be. So the injectors wouldn't actually be a tuning issue, if the STi manifold and fueling physically bolts to the EJ255, which I'm pretty sure will (just not vice-versa).

Arrows 2009-10-27 05:37 PM
Okay, so it's been so long since I've been in contact with the car that I forgot what year it was. It's an 05. Off by one. Whoops...

Here is a summary of the main parts that what Lithia wanted to replace (for $7078 )

Short Block
Timing Belt
Oil Pump
A bunch of gaskets
Adjuster of some sort
Idler
& Oil & coolant

I'd be more descriptive but that's all it says on their quote sheet, if you guys know part numbers I'll throw those up.

I have a complete (minus wiring harness, ecu, intake, and intercooler) 06 WRX Turbo engine

100_Percent_Juice 2009-10-27 05:43 PM
Quote:
Originally Posted by sperry (Post 141405)
Well I guess in the future I'll refrain from asking you legitimate questions. I thought "'06 WRX's have side-feed '04 STi injectors?" was a pretty straightforward thing to ask when someone states the '06 WRX has "the same" injectors as an '04 STi and I was pretty sure that no WRX's ever had side-feeds. Sure I was wrong about the sizes, but the point I was making about needing tuning was still correct.

If you want to start pointing out misinformation, you can start with your post in the thread:



...because you would in fact need to change the tune for the different injector latencies between the '06 WRX and '04 STi injectors, even though they're both rated for similar flow (if you consider 535 the same as 560). So really, the "similarity" of the injectors makes nothing much easier since the latencies will have to be updated and the flows scaled.

So then... for reference:

All WRXs have top-feed injectors.
'02 to '05 are 420cc top-feeds, latencies: 2.79, 1.49, 0.98, 0.68, 0.38 (in Cobb AP voltage order)
'06+ are 560cc top-feeds, latencies: 4.70, 2.65, 1.73, 1.20, 0.99

Some STi's have side-feeds, some have top-feeds:
'04-'06 STi are 535cc side-feeds, latencies: 7.66, 2.69, 1.37, 1.05, 0.75
'07+ STi are 560cc top-feeds, (which I'm assuming are the same as the '06+ WRX injectors)

So, when attempting to swap an '06 WRX motor into an '04 STi, you're going to need to re-tune the ECU for the injectors, even if you re-use the STi's turbo and intercooler.
Just so attitude can't be read into my post I will add this.

*Calm non-sarcastic tone*

I really don't care who is right or wrong. I did not have a good day today and it clearly went into this thread.

ScottyS 2009-10-27 06:34 PM
Quote:
Originally Posted by Arrows (Post 141411)
Okay, so it's been so long since I've been in contact with the car that I forgot what year it was. It's an 05. Off by one. Whoops...

Here is a summary of the main parts that what Lithia wanted to replace (for $7078 )

Short Block
Timing Belt
Oil Pump
A bunch of gaskets
Adjuster of some sort
Idler
& Oil & coolant

I'd be more descriptive but that's all it says on their quote sheet, if you guys know part numbers I'll throw those up.

I have a complete (minus wiring harness, ecu, intake, and intercooler) 06 WRX Turbo engine
Simplicity says that you build the STi engine back up to avoid hybridizing issues. The shortblock is the only really expensive part, maybe it's just me, but I would think that a complete 06 motor would sell for enough to get all the stuff you need. Otherwise, as others have stated, tearing the 06 motor apart for the block (if same as 05 STi) and small bits might be feasible, and sell the rest.

Arrows 2009-10-27 07:12 PM
Quote:
Originally Posted by ScottyS (Post 141419)
Simplicity says that you build the STi engine back up to avoid hybridizing issues. The shortblock is the only really expensive part, maybe it's just me, but I would think that a complete 06 motor would sell for enough to get all the stuff you need. Otherwise, as others have stated, tearing the 06 motor apart for the block (if same as 05 STi) and small bits might be feasible, and sell the rest.
Well from what I can gather the 05 STi shortblock is the same as the 06 WRX shortblock so I think thats what I'm gonna be doing & parting out all the stuff I don't need/cant use off the 06 engine.

ScottyS 2009-10-28 10:49 AM
Quote:
Originally Posted by Arrows (Post 141422)
Well from what I can gather the 05 STi shortblock is the same as the 06 WRX shortblock so I think thats what I'm gonna be doing & parting out all the stuff I don't need/cant use off the 06 engine.
Cool, we are rooting for your success!

A1337STI 2009-10-28 09:33 PM
I know of an sti block for $250 (broken rod bearing) if that helps you any

not sure year, i could ask though

Arrows 2009-10-29 03:08 PM
If anyone knows of any shops in town willing to do this that would help. I'm going to go talk with Lithia about it but I'm pretty sure they're gonna try and rape my wallet to do the work...

cody 2009-10-29 03:29 PM
http://www.seccs.org/forums/showthre...highlight=aims

sperry 2009-10-29 03:35 PM
Quote:
Originally Posted by Arrows (Post 141498)
If anyone knows of any shops in town willing to do this that would help. I'm going to go talk with Lithia about it but I'm pretty sure they're gonna try and rape my wallet to do the work...
If you're just swapping the shortblock, and you're mechanically inclined, you can do it yourself. It's basically just a little more work than a head-gasket swap.

knucklesplitter 2009-10-29 05:28 PM
Quote:
Originally Posted by Kevin M (Post 141408)
I thought '04 STis had the same injectors as the EJ207, but I could very well be wrong. Like I mentioned, it's been years since I really strained to keep up with what swaps where (other than older NA stuff).
As Charlie Murphy would say, "Wrong. Wrong!"

;)

2004 STIs have side-feed 550-ish injectors. Whereas EJ207 have top-feed injectors.

Kevin M 2009-10-29 07:15 PM
I guess that makes me Rick James, bitch! :lol:

(I'm glad that's actually funny to me again. It's been a while.)

Arrows 2009-10-30 03:43 PM
Quote:
Originally Posted by cody (Post 141501)
Thank you very much!

Although I've never ripped apart a car engine, I'm quick to learn mechanical stuff. I just don't have the tools to do it... :|

sperry 2009-10-30 04:02 PM
Quote:
Originally Posted by Arrows (Post 141563)
Thank you very much!

Although I've never ripped apart a car engine, I'm quick to learn mechanical stuff. I just don't have the tools to do it... :|
IIRC the only "odd" tools you'll need are a big-ass allen wrench for the cam bolts, and a 12-point socket (12mm?) for the head bolts (at least my ARP head bolts use 12-point heads... I'm not sure about OEM head studs).

Cory can probably remember off the top of his head what's needed... but I don't remember there being anything too unusual.

Dean 2009-10-31 02:42 PM
Quote:
Originally Posted by sperry (Post 141564)
IIRC the only "odd" tools you'll need are a big-ass allen wrench for the cam bolts, and a 12-point socket (12mm?) for the head bolts (at least my ARP head bolts use 12-point heads... I'm not sure about OEM head studs).
Allen head socket set at HF is cheap and head/main bolts are 12 points .

MPREZIV 2009-11-02 07:31 AM
10mm allen for the cam bolts, (and a huge breaker bar, and a MattR...) and the head bolts are 14mm twelve point.

Dean 2009-11-02 07:52 AM
The things I found with the cam bolts are.

A. Make sure the allen fits very tight and is fully seated. Use paper to shim if needed. Yes, paper.

B. Move the breaker bar as fast as possible like an impact, don't just do a slow build up of torque. The later for me at least was what almost lead to having to drill one out.... Fast worked great on the other 7 I've done.


All times are GMT -8. The time now is 07:24 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
All Content Copyright Subaru Enthusiasts Car Club of the Sierras unless otherwise noted.