Welcome to the North American Subaru Impreza Owners Club Wednesday July 26, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 07-07-2015, 01:59 PM   #1
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default WRX manifold mod to fit your 2.5i!!!

Hello folks it is your old pal GEE OTTO here to post about the mythical and elusive WRX/LGT stock manifold modified to fit the 2.5i platform and other useful information about the rest of the exhaust.

Many years and many, many hours of research and trial and error were put into getting this done right. I made a thread 2 or 3 years ago to float the idea and gather feedback, which came in the form of positive and negative responses. I've put out interest threads to build a header, ive worked with people to develop their own prototypes and UEL solutions. I remember talking to Mike years ago about his UEL header which is now Rallisport Racing (Great headers and quality).


***I understand both sides. As a car guy I want performance over anything else but with a non-turbo EJ thats not realistic for the cost as opposed to say a I4 platform. I would call Mach V up and have a set built + a dyno tune to yield MAX POWER but that may cost more than the car is worth @ 8 years old even more than a turbo kit. So please keep that in mind before you bash the guys/girls that merely want the info of OPTIONS to convert to UEL. That is why we exist to help others do funky mods to theirs cars turbo or not, dumb or smart, rice or wheat.****

So first some info about this project/mod:
1. You don't lose bottom end power
2. You don't lose top end power
3. Your cars acceleration is equally linear
4. You car sounds like a stock WRX/LGT afterwards
5. It does not impede the oil filter in fact it makes oil changes 10x easier
6. Your second cat IS sufficient to keep the CEL off and your fuel mileage the same
7. It will not melt your water pump outlet
8. It does fit under the stock splash tray with plenty room to spare
9. You do not get the sewing machine sound under load
10. You don't have to fab a new mid-pipe
11. You only have to extend your rear (gray) O2 sensor
12. The WRX/LGT manifold fits the EJ253
13. The stock flange is a 3 bolt 2.25" NOT 2.5" flange !

In terms of difficulty this would be a 7/10. You will need these parts:
05+ LGT/WRX/STi manifold
2.25" three bolt flange with ROUND holes and a set of Grimmspeed THICK cross-pipe to elbow gaskets see my diagram below:

A Casper Electronics Rear (gray) 36" O2 extension
Two standard O2 bungs
A thick 2.25 inch three bolt gasket
Photo of the parts (notice the thick GrimmSpeed gaskets installed btwn the cross pipe and collectors):



The most difficult part of this process is finding a shop that will chop and weld the manifold. Cast Steel scares many a welder, so ask around and explain to them what you want done, take a picture with you .

So far LM24 in the Tristate area and Mach V in the greater DC Metro area will do it for a good price and do it right. Once you find a shop they will be able to do the entire project for you.

Some tips from me after three UEL attempts:

Try not to splice the O2 sensor(s) if you have to move the AFR sensor (orange) reroute the wiring harness back through the intake manifold and down the back of the engine first! Then connect the orange and place it where you or your fabricator sees fit. If you do splice them make sure to use the proper braided wire not the solid copper stuff.

Buy the rear (gray) O2 extension! Trust me there is nothing better than having a Bolt on UEL setup that you can swap out to your stock setup with the turn of a wrench and unplugging of a sensor. There is also much to be said about peace of mind

DO not rush the process! Don't settle for a old beat up Stock manifold, I bought a EJ20K manifold it was in bad shape but cheap it wouldn't even fit my block, and I ruined the bolt flange b/c it was so rusted together I had to use a torch and cutting wheel to separate the three parts. Well trust me when I say: grey iron doesn't like the heat an Oxy/Acetylene torch puts out

Keep a look out for a clean EJ255/7 (05+) stock manifold. Also buy a good thick flange as well for the new connection to your stock mid-pipe. You will find plenty of 1/4" flanges but you want at least 3/8" and preferably a 1/2". This insures during the welding process you don't experience any warping.

Do some research on the rest of your exhaust well ahead of time as well. I like mellow tones and overall quiet operation SO I went with stock LGT cans and my stock Y pipe. For now this setup is as quiet as the stock 2.5i system. Most of us that have/will done/do this mod want to have something to show for it so naturally a CBE is in the mix of future additions.

I would suggest you stick with your stock CBE and swap out parts in groups like muffler(s) first, then a resonator, then full custom if you are unhappy.

I say that b/c typically a shop will fabricate the exhaust with thin walled mild steel instead of thicker 304 grade steel. Thinner steel has issues like, poor corrosion resistance, emitting mechanical sounds, lower crush tolerance, and the interior has a higher coefficient of friction. However it is cost effective and with a few coats of Hi-Temp header paint you will have a durable custom setup.

I would also go for an 18" minimum resonator, you want to go with a double walled, fiberglass packed resonator. If you cheap out on this component you will suffer from drone and rasp, so look at brands like Vibrant, Thrush, Borla, etc.

Along with custom piping comes your choice of mufflers I would avoid a straight through muffler i.e. FlowMaster 40's or Super 44's, cheap 115mm melon cannons you find on eBay or cheap exhaust shops. Instead look for chambered and well packed mufflers like a Flowmaster 60 Series, Thrush Hush Super Turbo, MagnaFlow Universals or any other well flowing well insulated muffler.


And now some pictures of my recently completed setup as reference for your own project should you choose to follow.






Also an be done this way




Another great example:
http://forums.nasioc.com/forums/show...ght=wrx+header

Many many ways to achieve your UEL goal!


As you can see in the first example the stock splash shield fits perfectly and will not melt. The stock size oil filter clears easily. You can also see how I positioned the rear O2 sensor so it isn't directly exposed to road elements (snow, rain, salt, debris). The front sensor is placed in a similar fashion for the same reasons and because there isn't much slack with the connector in the stock location under the intake manifold.

In the second example you can see that NO cutting was needed but your transition will be a tighter angle and you will chop your midpipe instead of the header. In both methods you place the AFR directly downstream of the merge and the O2 efficiency sensor directly downstream of the second cat.

A performance shop will probably opt for the second method as not many want to deal with cast steel BUT you loose that bolt-on/bolt-off quality.

Reflections:
Keep an open mind about the end result and be willing to change components as needed to achieve your desired effect.

Be clear when approaching a shop or welder to do this project, print my pictures, take them with you, show them. This is a big part of getting a yes versus a “nah I can’t do that.”

I wish I went with this setup three years ago it is as quiet as stock and I have the option to go LGT CBE or back to stock at anytime. Oil changes are easier and there is no degradation in fuel mileage or vehicle behavior. Also this setup is solid, compact and durable.
* Registered users of the site do not see these ads.

Last edited by GEE-OTTO; 07-08-2015 at 12:10 PM.
GEE-OTTO is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-07-2015, 02:43 PM   #2
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Scores:
10/10 for figuring this out and posting an informative thread.
1/10 for posting pictures that appear to have been taken with a 1megapixel camera from 1997 with no flash
Patrick Olsen is offline   Reply With Quote
Old 07-07-2015, 03:28 PM   #3
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

HAHAHA Thank you for the 11/20 overall I took them a LONG time ago on a damaged iPhone 1 (yes that old ass phone) I wil update pictures this week while I change the oil!

I hope this gets "sticky"!
GEE-OTTO is offline   Reply With Quote
Old 07-07-2015, 04:35 PM   #4
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
HAHAHA Thank you for the 11/20 overall I took them a LONG time ago on a damaged iPhone 1 (yes that old ass phone) I wil update pictures this week while I change the oil!

I hope this gets "sticky"!
Where did you get your Grimmspeed gaskets?

The diagram above is the only part that I get lost at lol, like I mentioned before i'm not the most car savvy person so this is all still a learning process for me.

What exactly am I looking at in that diagram you made above?

Would I be able to do header only and just get the wrx header setup to my car and worry about the CBE and everything else I wanna do later?

My main concern is getting a UEL header I can swap in/out with my stock ones if needed.

Figure if I get the UEL done first and out of the way, I can get the CBE when the time and money is right knowing I already have the UEL done.

Also quick edit - do you only need the thick grimmspeed gaskets for the connector if I get a stock manifold? The ones on ebay don't look like they have that centerpipe that connects to the ends of the header. it's all just one piece until you get to the up-pipe

Last edited by Twinge; 07-07-2015 at 05:23 PM.
Twinge is offline   Reply With Quote
Old 07-07-2015, 10:51 PM   #5
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Well I'm not sure how more clear the thread can be the thread is for a STOCK WRX/LGT/STI manifold modded to fit your 2.5i the diagram merely shows you what happens if you get a slotted hole flange. Some headers are three piece some are 1 piece just depends on what you get, if you go that route then reference this as a general guide as to what will need to be done.

CBE and the like are indifferent to your header choice so altering that is at your desire/intent/liking

Last edited by GEE-OTTO; 07-07-2015 at 10:59 PM.
GEE-OTTO is offline   Reply With Quote
Old 07-17-2015, 12:09 AM   #6
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

I hope this gets sticky'd!!!!
GEE-OTTO is offline   Reply With Quote
Old 07-17-2015, 11:05 AM   #7
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Quote:
Originally Posted by GEE-OTTO View Post
I hope this gets sticky'd!!!!
They're probably just waiting on those updated pictures.
Patrick Olsen is offline   Reply With Quote
Old 07-20-2015, 12:05 PM   #8
silvercookie
NASIOC Supporter
 
Member#: 180033
Join Date: May 2008
Chapter/Region: Tri-State
Location: Queens, NY, 11385
Vehicle:
2005 WRX
PSM

Default

Question. Do you know if the catback fitment is the same on the 09 legacy as a 06 outback?
Excellent write up.
silvercookie is offline   Reply With Quote
Old 07-20-2015, 01:04 PM   #9
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Quote:
Originally Posted by silvercookie View Post
Question. Do you know if the catback fitment is the same on the 09 legacy as a 06 outback?
Excellent write up.
The "Y" pipe is identical the mufflers are not. You would need to extend the tips a few inches to the clear the bumper OR have "turn-downs" welded on to each can to direct the exhaust.

Thanks! I am going to take new pictures
GEE-OTTO is offline   Reply With Quote
Old 07-23-2015, 04:29 PM   #10
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

If all goes well this saturday I'll be adding some pics of the aftermath

He told me to get there around 12 so leaving my house around 10:30-11 AM saturday morning, getting it done at some shop my buddy referred me to in Bethany, CT.

Appointment moved up to 10 in the morning instead, I'm okay with that, the earlier the better!

Still haven't decided if I want to go catback or axleback

Last edited by Twinge; 07-23-2015 at 09:55 PM.
Twinge is offline   Reply With Quote
Old 07-25-2015, 04:10 PM   #11
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Alright guys I just arrived back home after getting this modification done.
I have a 2009 2.5i hatchback

Here is a complete list of everything I bought :
o2 Sensor Extension(Didn't end up needing to use this)
02-07 WRX UEL Header
3 Bolt 2.25 inch flange(I bought 2 of these)
o2 Sensor Bung

Here are a few pictures showing the header on and where it was cut, we also had to cut an inch or two from the midpipe. Also shows you the clearance for the oil filter now, oil changes will be so much easier!





Twinge is offline   Reply With Quote
Old 07-25-2015, 04:40 PM   #12
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

And there you have it folks. Nice work routing the mid pipe to clear the frame.

Now to keep it mellow
GEE-OTTO is offline   Reply With Quote
Old 07-25-2015, 04:44 PM   #13
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Wait where are your AFR and cat effeciency sensors???
GEE-OTTO is offline   Reply With Quote
Old 07-25-2015, 04:47 PM   #14
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
Wait where are your AFR and cat effeciency sensors???
both the o2 sensors are on the other side of the modified pipe on the last picture, you cant see them in any of the pics, we used the same o2 bung that came in the header and then drilled a hole into the fabbed piece for the 2nd one
Twinge is offline   Reply With Quote
Old 07-25-2015, 10:41 PM   #15
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Are you getting a tactrix cable to disable the P0420 b/c its a matter time before it pops up. I saw that you didnt use your extension the whole point of it was to put the second bung at the second OEM cat
GEE-OTTO is offline   Reply With Quote
Old 07-25-2015, 11:18 PM   #16
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
Are you getting a tactrix cable to disable the P0420 b/c its a matter time before it pops up. I saw that you didnt use your extension the whole point of it was to put the second bung at the second OEM cat
I thought it was supposed to go in the modified part of the header, or else I would have told him to put it there.

CEL actually just came on on my way home from the bar.

Is the tactrix cable the only way to get it to go off? The guy who did the fabbing said if I got an o2 spacer and put the o2 sensor in there the CEL would go away.

Can you verify this?
Twinge is offline   Reply With Quote
Old 07-26-2015, 12:15 AM   #17
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

This entire thread......


Spacers dont work, have a bung placed behind that second cat and use your extension to make it reach.

You will be in limp mode until its fixed.

That or buy a tactrix 2.0 cable disable the P0420 DTC
GEE-OTTO is offline   Reply With Quote
Old 07-26-2015, 08:50 AM   #18
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
This entire thread......


Spacers dont work, have a bung placed behind that second cat and use your extension to make it reach.

You will be in limp mode until its fixed.

That or buy a tactrix 2.0 cable disable the P0420 DTC
Okay, I talked to the guy who did the work and told him, going to go down next saturday again and have him re-install it at the 2nd cat.

Will it be bad to drive with this code on for a week?

Other than that my car seems to be running great, and my gas consumption has also been at 25.5 instead of the average 22.5 I get after changing the headers. Not sure if it will stay that way though.

Also when you say behind the 2nd cat, is it going on the side closer to the header or closer to the muffler of the cat? I'm guessing the side of the cat thats closer to the muffler/rear of the car?
Hard to tell from the picture which side of the cat its located on

Last edited by Twinge; 07-26-2015 at 09:13 AM.
Twinge is offline   Reply With Quote
Old 07-26-2015, 02:55 PM   #19
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

You will want to have it placed downstream of the cat.
GEE-OTTO is offline   Reply With Quote
Old 07-26-2015, 06:20 PM   #20
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
You will want to have it placed downstream of the cat.
I'm still not fully sure what you mean by downstream of the cat lol, sorry I'm still in a learning process lol, im a newbie.



So would you put it where the o2 sensor is in this diagram facing towad the header or on the other side of the cat facing toward the resonator and muffler?

I figure by downstream you mean on the other side facing toward the resonator and muffler but I want to be 100% sure before I tell this guy where to relocate it come saturday.

Also it should be insterted on the top of the pipe correct?
Twinge is offline   Reply With Quote
Old 07-26-2015, 08:57 PM   #21
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Yes you want the O2 bung on the side of the cat that faces the resonator. You will then use that extension to plug the sensor back into the factory location.
GEE-OTTO is offline   Reply With Quote
Old 07-26-2015, 09:44 PM   #22
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
Yes you want the O2 bung on the side of the cat that faces the resonator. You will then use that extension to plug the sensor back into the factory location.
Okay so opposite the diagram.

Thanks again for the help.

Will report back next saturday with pictures or relocated o2 sensor and hopefully no CEL
Twinge is offline   Reply With Quote
Old 07-31-2015, 01:47 PM   #23
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2009 Legacy GT
OBP

Default

Quote:
Originally Posted by Twinge View Post
Okay so opposite the diagram.

Thanks again for the help.

Will report back next saturday with pictures or relocated o2 sensor and hopefully no CEL
That diagram is for a turbo car totally different and for an older EJ255. The sensor sniffs exhaust as it exists the converter, so like the stock manifold has that sensor past the cat so should the new configuration
GEE-OTTO is offline   Reply With Quote
Old 07-31-2015, 06:54 PM   #24
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Quote:
Originally Posted by Twinge View Post
I'm still not fully sure what you mean by downstream of the cat lol, sorry I'm still in a learning process lol, im a newbie.
Exhaust gasses are like water, they flow downstream. The engine is the upstream side, the exhaust tip at the rear of the car is the downstream side. Downstream of the cat means after the cat as the exhaust is flowing away from the engine.
Patrick Olsen is offline   Reply With Quote
Old 08-01-2015, 01:08 AM   #25
Twinge
Scooby Newbie
 
Member#: 387486
Join Date: Apr 2014
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
2009 2.5i Hatch
Silver

Default

Quote:
Originally Posted by GEE-OTTO View Post
That diagram is for a turbo car totally different and for an older EJ255. The sensor sniffs exhaust as it exists the converter, so like the stock manifold has that sensor past the cat so should the new configuration
I went to the shop on thursday and got a axleback exhaust w/ performance resonator, I already want it louder though lol.

When the car idles at a cold start it sounds nice, but once it warms up it quiets down a lot and you can barely hear anything, also you only really hear anything when you're accelerating. I want a deeper and slightly louder noise maybe, would also like a slightly deeper note while idling/cruising at the same speed if possible.

Think I am going to go back to the shop, and have them cut out the stock resonator and just weld in a pipe there.

Quote:
Originally Posted by Patrick Olsen View Post
Exhaust gasses are like water, they flow downstream. The engine is the upstream side, the exhaust tip at the rear of the car is the downstream side. Downstream of the cat means after the cat as the exhaust is flowing away from the engine.
Makes sense, thanks for the explanation.

Here's a short video clip of the sound.

2.5i UEL Header Axleback Exhaust
Twinge is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 11:37 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.