Welcome to the North American Subaru Impreza Owners Club Thursday September 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Vancouver Impreza Club
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Chapters > Vancouver Impreza Club Forum -- VIC

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 11-23-2003, 03:24 PM   #1
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default Exhaust systems?

So which exhausts would pass AirCare?

Obviously a straightpipe probably won't... but yeah...
* Registered users of the site do not see these ads.
Lantec is offline   Reply With Quote
Old 11-23-2003, 06:47 PM   #2
Penphoe
Friendly Neighbourhood
Moderator
 
Member#: 269
Join Date: Sep 1999
Chapter/Region: VIC
Location: Burnaby, B.C., Canada
Vehicle:
2005 ABP LGT LTD BP6
00 Impreza RS GM6 RIP

Default Re: Exhaust systems?

Quote:
Originally posted by Lantec
So which exhausts would pass AirCare?

Obviously a straightpipe probably won't... but yeah...
If all you're doing is changing the midpipe and the muffler, then almost any exhaust system out there will pass AirCare. The muffler itself has nothing to do with emissions, but to do with noise control.

However, if you replace the catalytic convert and/or header, then you may run into problems. With the headers, it may flow too well, and the exhaust gasses might cool down too much before it hits the cat. This is an example of the infamous cat. efficiency CE light. With the cats, if you replace them with a test pipe, then obviously you won't pass Airscare. With a highflow cat, it might not scrub enough of the bad emissions well enough to pass either, but I'm not 100% sure on this.

LaterZ!
Darren!!
Penphoe is offline   Reply With Quote
Old 11-24-2003, 01:54 PM   #3
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

ah.

what about the uppipe and downpipe people talk about???
Lantec is offline   Reply With Quote
Old 11-24-2003, 02:19 PM   #4
au112
Scooby Specialist
 
Member#: 4412
Join Date: Feb 2001
Location: Port Moody BC Canada
Vehicle:
MY01 Impreza 2.5RS
BRP

Default

Quote:
Originally posted by Lantec
ah.

what about the uppipe and downpipe people talk about???
These apply for turbo car

Andy
au112 is offline   Reply With Quote
Old 11-24-2003, 02:46 PM   #5
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

Quote:
Originally posted by au112
These apply for turbo car

Andy
.... Oh....


and the Intakes and stuff.. what are those??

sorry for sounding like a n00b
Lantec is offline   Reply With Quote
Old 11-24-2003, 03:45 PM   #6
quest
*** Banned ***
 
Member#: 42402
Join Date: Aug 2003
Location: 4 inches south of :coffeemug:
Vehicle:
- Finder of Porn
-Bringer of tears...

Default

intakes won't affect Air care. Basically, you've got headers- cat section-midpipe-muffler. The cat section is the only part that really affects Air care.

Of course, i'm a newb so I could be wrong
quest is offline   Reply With Quote
Old 11-24-2003, 04:14 PM   #7
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

Quote:
Originally posted by quest
intakes won't affect Air care. Basically, you've got headers- cat section-midpipe-muffler. The cat section is the only part that really affects Air care.

Of course, i'm a newb so I could be wrong
Exactly, you are wrong. There are heaps of factors which affect aircare including spark plugs, air filter of course the cats and more. Almost anything that affects air fuel ratio our exhaust will affect air care. Your emissions can change when you run more power, different cams, different injectors....all will affect aircare. Generally though if you are running both cats you should be able to pass.

For an NA car if you really want good power I would recommend:
An intake like Ganzflow, PDM or for more bucks COBB. A bored out throttle body, some mild head work, cams, headers and nothing over a 2.5 inch exhaust. Also a good Tuning program for your ECU and management of all the parts you have. Also I would get a lightened flywheel and crank pulley. A lightened flywheel will probably make the most noticeable difference in power and drivability of the car aws far as power and acceleration goes.
tora is offline   Reply With Quote
Old 11-24-2003, 05:47 PM   #8
quest
*** Banned ***
 
Member#: 42402
Join Date: Aug 2003
Location: 4 inches south of :coffeemug:
Vehicle:
- Finder of Porn
-Bringer of tears...

Default

lol...at least I tried...that's what I get from doing some half-assed research
quest is offline   Reply With Quote
Old 11-24-2003, 05:52 PM   #9
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

No problem, we're all here to learn. I have the luxury of asking two very good mechanics (one an 8 year Subaru tech, the other an ex-WRX pitt crew member)....so it kinda helps.
tora is offline   Reply With Quote
Old 11-24-2003, 06:03 PM   #10
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

so if I did an EJ20 swap... what could I do to the whole intake/exhaust system to make more power yet keep it still air care-able.....

^Air Careable? is that even a word?
Lantec is offline   Reply With Quote
Old 11-24-2003, 06:14 PM   #11
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

If you an EJ20 swap you can do anything that people are doing on a WRX. I would say go this route:
1. up-pipe
2. downpipe
3. exhaust
4. bigger turbo
5. bigger injectors
6. bigger fuel pump
7. tuned ECU

Now all of those EXCEPT the downpipe will be fine for getting through aircare. SO, I would recommend doing the downpipe, but keep your stock one and put it back on when you have to get aircared.
tora is offline   Reply With Quote
Old 11-24-2003, 06:16 PM   #12
Spooled
Scooby Specialist
 
Member#: 14958
Join Date: Feb 2002
Chapter/Region: VIC
Location: Vancouver, BC
Vehicle:
1991 318is
Silver

Default

I've heard of people down in California passing smog checks with an aftermarket cai, catless uppipe, but also with an aftermarket downpipe with highflow cats. I dunno though (This is for the EJ20 just so you know, Lantec). I'm sure someone like tora could answer that for you.

EDIT: Jamie! You've now made my post worthless!
Spooled is offline   Reply With Quote
Old 11-24-2003, 06:39 PM   #13
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

For the extra cost of having hi-flow cats I would say put that into the labor every two years to put your stock downpipe back on. Now there are also those of us (jik....jak.....paddywhack) who will be running JDM turbo-backs who will have to reinstall the entire exhaust systems because the stock downpipe will not mate up....although just for aircare it may...
tora is offline   Reply With Quote
Old 11-24-2003, 07:08 PM   #14
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

Quote:
Originally posted by tora
If you an EJ20 swap you can do anything that people are doing on a WRX. I would say go this route:
1. up-pipe
2. downpipe
3. exhaust
4. bigger turbo
5. bigger injectors
6. bigger fuel pump
7. tuned ECU

Now all of those EXCEPT the downpipe will be fine for getting through aircare. SO, I would recommend doing the downpipe, but keep your stock one and put it back on when you have to get aircared.

but if I kept the stock downpipe and but had everything else would I still gain power and still be able to pass air care?
Lantec is offline   Reply With Quote
Old 11-24-2003, 07:12 PM   #15
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

You would have more power over stock and you would most likely pass aircare, especially if your ECU had a valet mode. But you would be missing out on heaps of power due to having the two cats.
tora is offline   Reply With Quote
Old 11-24-2003, 07:14 PM   #16
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

Quote:
Originally posted by tora
You would have more power over stock and you would most likely pass aircare, especially if your ECU had a valet mode. But you would be missing out on heaps of power due to having the two cats.

Doh!

so what exactly is an uppipe and a downpipe? and why would it go through 2 cats?
Lantec is offline   Reply With Quote
Old 11-24-2003, 07:53 PM   #17
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

There is one cat on the up-pipe, it's purpose is as a pre-warmer for the other two cats to make sure they are working at full efficiency as soon as possible. The other two cats are on the downpipe which is made of two sections, so you can take out just one of the dowpipe cats. Taking out the up-pipe cat does not affect aircare PROVIDED you warm the car up completely (at least 30 minutes plus some highway driving) before going.
tora is offline   Reply With Quote
Old 11-24-2003, 08:02 PM   #18
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

Quote:
Originally posted by tora
There is one cat on the up-pipe, it's purpose is as a pre-warmer for the other two cats to make sure they are working at full efficiency as soon as possible. The other two cats are on the downpipe which is made of two sections, so you can take out just one of the dowpipe cats. Taking out the up-pipe cat does not affect aircare PROVIDED you warm the car up completely (at least 30 minutes plus some highway driving) before going.
So essentially, there's 3 cats but I only need 1 to pass the test provided that I warm up the car completely before doing the test?
Lantec is offline   Reply With Quote
Old 11-24-2003, 08:23 PM   #19
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

Nope, you need both your downpipe cats.
You would be very lucky to get by on one cat...that would only happen possibly IF you had no other mods to the car.
tora is offline   Reply With Quote
Old 11-24-2003, 11:36 PM   #20
Lantec
Scooby Specialist
 
Member#: 48685
Join Date: Nov 2003
Location: Coquitlam, B.C.
Vehicle:
2010 Prius
Silver

Default

Quote:
Originally posted by tora
Nope, you need both your downpipe cats.
You would be very lucky to get by on one cat...that would only happen possibly IF you had no other mods to the car.

Ah. I see
Lantec is offline   Reply With Quote
Old 11-25-2003, 05:09 PM   #21
deft
Scooby Specialist
 
Member#: 46624
Join Date: Oct 2003
Location: Vancouver, BC
Vehicle:
2004 WRX
World Rally Blue

Default

If running with two cats is what you will need to pass aircare. Isn't running catless period, or just with one highflow cat in your exhaust irresponsible? How dirty is the exhaust actually going to be if there is only one or less cat in the exhaust?

What I am trying to say, is even though going with one cat or less is good for power, is it morally responsible(enough)?
deft is offline   Reply With Quote
Old 11-25-2003, 05:37 PM   #22
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

Well, morality goes out the window as soon as we step in the car by your argument doesn't it? Anyways, only cities with large populations have aircare. My car was registered in Whistler before and I didn't need aircare, it was also registered in Victoria and I didn't need aircare. If we want to be MORALLY responsible we should all drive echo's or scooters (TMR) or Honda insights or whatever....no?
tora is offline   Reply With Quote
Old 11-25-2003, 05:56 PM   #23
deft
Scooby Specialist
 
Member#: 46624
Join Date: Oct 2003
Location: Vancouver, BC
Vehicle:
2004 WRX
World Rally Blue

Default

Well I didn't say it's wrong to step in a car, not at all, I don't really know where you're getting that from. And yes, of course there is a step down in emissions, when you go from something like a scooter, toyota prius, or honda insight. However, there's still a difference between a stock exhaust on a WRX and a catless exhaust. What I'm trying to say is how much more harm is this doing to the environment?

Yes, anyone could say that this one car, in the scheme of things is not going to make an appreciable difference, but that's not important to me. What's more important, is the principle, for me at least. So in the end, I would really like to know, how much dirtier my above example would be measured as?
deft is offline   Reply With Quote
Old 11-25-2003, 06:01 PM   #24
tora
Scooby Guru
 
Member#: 5851
Join Date: Apr 2001
Chapter/Region: VIC
Location: Vancouver
Vehicle:
09 Forester XT
+ NA Miata

Default

A single cat will only eliminate maybe 2/3rd as much emmissions as a single cat.
tora is offline   Reply With Quote
Old 11-25-2003, 06:13 PM   #25
deft
Scooby Specialist
 
Member#: 46624
Join Date: Oct 2003
Location: Vancouver, BC
Vehicle:
2004 WRX
World Rally Blue

Default

In a previous post, tora, you said that the cat in the uppipe is sort of a pre-warmer, so it's not that necessary. But how well do hi-flow cats perform in the downpipe/midpipe, in flow, and emissions cleaning?
deft 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: Cobb 3" Cat Back Exhaust System or a quieter exhaust Yuman Private 'Wanted' Classifieds 13 02-05-2010 09:16 AM
Big Blow Out on Invidia N1 Exhaust Systems and Turbo Back Exhausts!! Spun Autosports MAIC Vendor Classifieds 3 10-10-2006 09:05 AM
ZERO/SPORTS Exhaust Manifold & World Leaguer Exhaust System! Edo Performance Engine/Power/Exhaust 0 08-24-2005 12:54 PM
Stock 01 RS exhaust system + air intake system davidlee Private 'For Sale' Classifieds 0 09-26-2003 07:49 PM
My entire exhaust system for sale! Andrew Bay Area Impreza Club Forum -- BAIC 13 03-10-2001 04:33 AM


All times are GMT -4. The time now is 07:41 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.