Welcome to the North American Subaru Impreza Owners Club Friday March 29, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 04-21-2004, 07:15 PM   #1
STI8U
Scooby Specialist
 
Member#: 54052
Join Date: Feb 2004
Location: Auckland, NZ
Vehicle:
2005 Spec C Type RA
WRC Blue

Default Do I need a Cold Air Intake?

I have an MY03 JDM STI (2.0L with VF37 twin scroll turbo) and have the following modifications that I'm going to install soon:

- 70mm downpipe
- 70mm - 80mm catback exhaust
- TurboXS UTEC
- Currently has aftermarket filter in stock air box

In stock form, the JDM STI runs 17psi at 4000rpm, dropping down to 14psi at 8000rpm redline. My goal is to get 19psi across the entire rev range.

My question is, with the above mods, is there any point in getting a CAI and aftermarket BOV (i.e. will I get more than 3HP with the CAI and can the stock BOV handle 19PSI)?

Or is my aftermarket filter in the stock air box and BOV sufficient?
* Registered users of the site do not see these ads.
STI8U is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-21-2004, 07:39 PM   #2
tino
Top Scoob 019
 
Member#: 43630
Join Date: Sep 2003
Location: Down Under
Vehicle:
2004 GT40R-built 2.5
604 whp @1.8 BAR on VP109

Default

dude,

these questions have been answered before. but briefly CAI dose not benefit subaru engines much at all. they cause the car to run leaner only used when u have an aftermarket ecu.

stock blowoff can handle round 1.3-.14bar.

i rekon wot u have there currently will be fine for ur setup.
tino is offline   Reply With Quote
Old 04-21-2004, 07:57 PM   #3
Thumper23
Scooby Specialist
 
Member#: 11571
Join Date: Oct 2001
Chapter/Region: RMIC
Location: Park City, UT
Default

yep, you don't need either
Thumper23 is offline   Reply With Quote
Old 04-21-2004, 09:44 PM   #4
pegdrgr
Scooby Specialist
 
Member#: 25693
Join Date: Oct 2002
Location: Portland, Or
Vehicle:
2008 18x9" goodness
E85-380ftlbs @ 3100

Default

If you are going to run only 19 psi you will not gain power with a CAI. The over sized MAF CAI becomes useful if you want to run a FMIC, or if you are making big power and running out of resolution of the MAF. With the stock IC and 19 PSI you are not going to qualify as NEEDING a CAI that is over sized. A stock sized one is useless unless you need to route a FMIC through the inner fender.

It pains me to tell you that some what, but I would rather you buy one becuase you need one, not because you thought you needed one.
pegdrgr is offline   Reply With Quote
Old 04-21-2004, 10:10 PM   #5
Red Rocket
Scooby Specialist
 
Member#: 10507
Join Date: Sep 2001
Vehicle:
'04 Ex STi Owner
'97 4Runner

Default

I personnally would recommend a CAI, but make sure it is properly setup - tuned for, gets proper air flow, etc. I would recommend the APS 65mm unit. A CAI will have less pressure drop then the stock pieces it replaces, and give a marginally cooler intake charge (but much cooler than a short ram). This means your turbo and intercooler don't have work as hard, and you gain headroom on your setup.

Skip the BOV.

Don't try to run 19 pis to redline, you'll probably just be blowing hot air.

Kevin
Red Rocket is offline   Reply With Quote
Old 04-21-2004, 10:51 PM   #6
pegdrgr
Scooby Specialist
 
Member#: 25693
Join Date: Oct 2002
Location: Portland, Or
Vehicle:
2008 18x9" goodness
E85-380ftlbs @ 3100

Default

Actually I would think he could run 19 psi on a 2.0 with that turbo. Notice that he is JDM, not US.
pegdrgr is offline   Reply With Quote
Old 04-22-2004, 02:23 AM   #7
SJwrx
Scooby Specialist
 
Member#: 14970
Join Date: Feb 2002
Chapter/Region: BAIC
Location: San Jose, CA
Vehicle:
1997 GF8
multi

Default

Quote:
Originally posted by tino
dude,

these questions have been answered before. but briefly CAI dose not benefit subaru engines much at all. they cause the car to run leaner only used when u have an aftermarket ecu.

stock blowoff can handle round 1.3-.14bar.

i rekon wot u have there currently will be fine for ur setup.
Ah, ignorance is great among the internet forums.

Talk to Injen and their dyno sheet... thats proof (oh, aswell as every major manufacturers car having a CAI on there cars, oh and the racing cars, and my car)

In short, they work quiet well, and most people are easy diverted away from them by other idiots.

Rich
SJwrx is offline   Reply With Quote
Old 04-22-2004, 02:50 AM   #8
911renegade
Scooby Newbie
 
Member#: 58442
Join Date: Mar 2004
Location: Washington State
Vehicle:
1975 911
undecided

Default

Quote:
Originally posted by pegdrgr
If you are going to run only 19 psi you will not gain power with a CAI. The over sized MAF CAI becomes useful if you want to run a FMIC, or if you are making big power and running out of resolution of the MAF. With the stock IC and 19 PSI you are not going to qualify as NEEDING a CAI that is over sized. A stock sized one is useless unless you need to route a FMIC through the inner fender.

It pains me to tell you that some what, but I would rather you buy one becuase you need one, not because you thought you needed one.
you guys are awesome I love it when you say "ONLY 19 PSI"
911renegade is offline   Reply With Quote
Old 04-22-2004, 04:30 AM   #9
tino
Top Scoob 019
 
Member#: 43630
Join Date: Sep 2003
Location: Down Under
Vehicle:
2004 GT40R-built 2.5
604 whp @1.8 BAR on VP109

Default

hey rich,

im not saying they dont work well, but u need the appropriate mods to go with them including an aftermarket ecu to handle the change in air flow.

on sti84 setup i dont think that theres gonna be a huge benefit, i think when moving to a larger non vf series turbo the true benefit can be shown.

its not ingnorance just an opinion and thats wot these forums are about. remeber also that these companies are gonna say that theres gains to be made cos they wanna sell their products. with the dyno sheet was the before and after dyno run done on the same day? was the car tied down at exactly the same load? was the temperature the same? theres a ton of factors that can influence a dyno reading and if the gains are only small then this can have a huge impact over the results.

look at aps with their sr40 didnt make anywhere near the power they quoted and they had dyno sheets to prove wot they had.
tino is offline   Reply With Quote
Old 04-22-2004, 08:15 AM   #10
1DOWNCLOWN
Scooby Specialist
 
Member#: 50287
Join Date: Dec 2003
Location: Franklin IN
Vehicle:
02 WRX
silver

Default

no
1DOWNCLOWN is offline   Reply With Quote
Old 04-22-2004, 08:26 AM   #11
mrbigisbudgood
Scooby Specialist
 
Member#: 54378
Join Date: Feb 2004
Chapter/Region: South East
Location: Charlotte, NC
Vehicle:
2023 WRX
WRB

Default

If you want to beat an SRT-4, you'll need a CAI and an MBC cranked up to 24psi.
mrbigisbudgood is offline   Reply With Quote
Old 04-22-2004, 09:26 AM   #12
pegdrgr
Scooby Specialist
 
Member#: 25693
Join Date: Oct 2002
Location: Portland, Or
Vehicle:
2008 18x9" goodness
E85-380ftlbs @ 3100

Default

Quote:
Originally posted by 911renegade
you guys are awesome I love it when you say "ONLY 19 PSI"
Honestly on the 207 motor I do not think that 19 psi is that much. If he were talking a 205 on the street then 19 would be a little high. I do not know of a turbo at 19 psi that will peg the MAF, hence the only 19 psi comment.
pegdrgr 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
If i get a cold air intake on my car do i need a tune or no? akazempoor Newbies & FAQs 9 09-25-2009 10:43 AM
Opinions on cold-air intake or no cold-air? gldenchld Tri-State Area Forum 7 11-06-2002 07:55 PM
I need a cold air intake. McLaren Formula 1 Forester Forum 1 10-04-2002 07:48 AM
AEM cold air intake or Injen cold air intake? energy57 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 31 05-20-2002 12:27 AM
Anyone need a cold air intake? subee_love Bay Area Impreza Club Forum -- BAIC 6 06-08-2001 02:17 PM

All times are GMT -4. The time now is 09:43 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.