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Old 07-20-2019, 10:12 PM   #1
HawkeyeNewb
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Default Street or competition IAG air oil separator

So I want to buy a oil separator and Iím not sure which one to go with. From my understanding the street series has two hoses going to be turbo inlet in the competition just has one large hose, correct me if Iím wrong. I was highly considering the competition strictly because it only has one hose which may clean up the engine bay, hopefully one hose will make a difference, LOL I plan on going with A bigger set up in the future but right now I just have a perrin stock style turbo inlet. I know the competition hose would be bigger than one that would fit on the parent but I could get some kind of adapter to step the hose down . Please help me out and give me some direction to go in and please share your opinions and/or concerns. I want to do it right the first time . thank you everyone!
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Old 07-20-2019, 10:21 PM   #2
JSR84
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https://www.iagperformance.com/IAG-C...g-eng-7251.htm

Read the product page, it'll answer your questions.
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Old 07-20-2019, 10:41 PM   #3
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Thank you for the link!! I had only read the ones on rally sport direct. Well I do plan on running e85 in the near future which they recommend the street version to try to evaporate as much water as possible . And I donít want a retune which they say will need to be done with the comp version.
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Old 07-21-2019, 04:50 AM   #4
viper_crazy
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Why would it need a tune with the comp version??
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Old 07-21-2019, 08:47 AM   #5
HawkeyeNewb
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The website says itís requires a tune??? Iím not sure. The street version retains the same set up as the original configuration which is why they donít suggest a read to me for the street version. But since the competition version vent to atmosphere it may alter the Intake charge very slightly Iím guessing. Maybe since itís originally tuned seeing some oil and contaminated in the air, when itís all gone it could affect the afr or give you more room for ignition without worrying about oil causing problems in the combustion. I honestly have no idea but just a guess. But the IAG website does suggest a return for the competition version and not the street version
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Old 07-21-2019, 08:50 AM   #6
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I think itís weird they say to run the competition version if you run pump gas under 600 hp or if you have a very high horse power above 600. But to only run the street series if you run under 600 horse power for ethanol. Itís kind of a pain when do you want the absolute best application as I am running pump gas now and I want to get the product now but want to run ethanol in the future and will have to end up paying another hundred dollars to get the conversion kit. So I donít know if I should just get the street version and run that on pump gas so it Will be ready for ethanol. Or get the competition version which it suggests to run for pump gas and then I have to pay another hundred dollars for the conversion kit once I run ethanol.
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Old 07-21-2019, 09:57 AM   #7
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The street version just is so cluttered with all those hoses I really hate it (((
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Old 07-21-2019, 12:02 PM   #8
Marvick08GT
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Street version, because most likely, NOT racecar. Lol..
Competition AOS is actually vent to atmosphere, hence the retune. The street is plumbed back into the inake tract for zero loss. You dont really need an AOS unless you heavily track the car. .02
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Old 07-21-2019, 12:53 PM   #9
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Quote:
Originally Posted by Marvick08GT View Post
Street version, because most likely, NOT racecar. Lol..
Competition AOS is actually vent to atmosphere, hence the retune. The street is plumbed back into the inake tract for zero loss. You dont really need an AOS unless you heavily track the car. .02
You may want to read the link and see why IAG recommends the 2 version the way they do. You also may want to research the subject before you give someone bad advice.
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Old 07-21-2019, 12:53 PM   #10
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The main reason I want this is for reliability reasons and to keep oil from builds up in the intake system. From what Iíve heard oil clown cars a problem in the combustion process which could cause a freak accident. Iíve already blown one motor so Iím kind of scared of doing it again and want to take every precaution possible to keep this motor healthy. I donít know how much of that theory comes from evidence and research or from scare people like me who have already blown their motor and will do anything to keep it from happening again
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Old 07-21-2019, 01:00 PM   #11
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And for the record my mods are basic like fuel pump, Iag tgv, turbo inlet, Cobb SF intake, catless down pipe, and Tomie exhaust, Boost solenoid with a JDMSTI ej255 out of a sg9 Forrester. I swapped the intake manifold from my old motor to the STI motor so that I could use my access port and keep top feed instead of side feed. Have a conservative tune at 18 pounds of boost, 320 to the wheels
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Old 07-21-2019, 01:05 PM   #12
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Quote:
Originally Posted by HawkeyeNewb View Post
And for the record my mods are basic like fuel pump, Iag tgv, turbo inlet, Cobb SF intake, catless down pipe, and Tomie exhaust, Boost solenoid with a JDMSTI ej255 out of a sg9 Forrester. I swapped the intake manifold from my old motor to the STI motor so that I could use my access port and keep top feed instead of side feed. Have a conservative tune at 18 pounds of boost, 320 to the wheels
Its a smart idea. There are several technical studies that provide insight into the topic.
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Old 01-24-2020, 09:19 PM   #13
AndrewD5418
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Bit random, but has anybody thought about using an e-vac scavenger with the competition series?
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Old 01-27-2020, 11:20 AM   #14
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Quote:
Originally Posted by HawkeyeNewb View Post
The main reason I want this is for reliability reasons and to keep oil from builds up in the intake system. From what Iíve heard oil clown cars a problem in the combustion process which could cause a freak accident. Iíve already blown one motor so Iím kind of scared of doing it again and want to take every precaution possible to keep this motor healthy. I donít know how much of that theory comes from evidence and research or from scare people like me who have already blown their motor and will do anything to keep it from happening again
Yeah, getting oil into the combustion chamber via blowby reduces the octane of your gas, among other things, making the engine more likely to knock and respectively, go boom.

Every turbo Subaru should have an AOS if you can swing it. It's an investment in reliability.
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Old 01-27-2020, 02:36 PM   #15
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Quote:
Originally Posted by BeastianSTI View Post
Every turbo Subaru should have an AOS if you can swing it. It's an investment in reliability.


That's a good one. No, it's really a waste of money in most peoples' cases.

Quote:
Originally Posted by HawkeyeNewb View Post
The main reason I want this is for reliability reasons and to keep oil from builds up in the intake system. From what Iíve heard oil clown cars a problem in the combustion process which could cause a freak accident.
The oil film in the intake is not of such a volume that this will happen with a healthy motor. If your rings are shot or turbo seals are worn, you should rebuild your motor. If you're running 25-30+ lbs of boost, you may benefit from an oil separator.

Quote:
Originally Posted by HawkeyeNewb View Post
And for the record my mods are basic like fuel pump, Iag tgv, turbo inlet, Cobb SF intake, catless down pipe, and Tomie exhaust, Boost solenoid with a JDMSTI ej255 out of a sg9 Forrester. I swapped the intake manifold from my old motor to the STI motor so that I could use my access port and keep top feed instead of side feed. Have a conservative tune at 18 pounds of boost, 320 to the wheels
You do not need an AOS. If you want to keep oil out of the intercooler, just reroute the PCV system. Search my posts - you may need to visit the images on Photobucket since their site is garbage for linking now.

https://forums.nasioc.com/forums/sho....php?t=2765219
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Old 02-07-2020, 08:35 AM   #16
si shane
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Quote:
Originally Posted by JSR84 View Post
You may want to read the link and see why IAG recommends the 2 version the way they do. You also may want to research the subject before you give someone bad advice.
That's exactly what the site says though! The comp version is vent to atmosphere vs. the street version which is vent to intake... So the more blowby the motor has, the more oil is pulled through the intake, the more you'll need a retune when you eliminate that oil by venting to atmosphere instead of venting to your intake stream.

It seems like there is some comedy to the companies reasoning, though. Air oil separators help reduce the amount of oil that's entering the intake stream when there is lots of blowby. If the stock configuration sends so much oil into the intake that you need to get the street air oil separator, but there is no significant change to the intake charge and no retune is needed - then what did the street version do? Do I misunderstand something about the function of these parts or am I being narrow in my assessment?
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Old Yesterday, 04:47 PM   #17
Nsmitty16
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Quote:
Originally Posted by HawkeyeNewb View Post
The street version just is so cluttered with all those hoses I really hate it (((
I agree it cleans up the bay and if your going to upgrade your setup you might as well get the competition one
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