FL4TBANGR

iTrader: (1)

Hey Everyone,

I wanted to take part in the group buy over at Nasioc for the Crawford AOS v2. I am currently stage 2. I was just reading about their AOS and seems even the v2 with the added coolant line has problems with the yellow sludge and making its way back into the engine and flaking of their powdercoating. Would I just be better not going with one and staying stock? I was thinking about going with the Grimmspeed AOS but I read problems about their AOS as well if you do a lot of turns and get G's up.

I don't do Auto-X or anything just daily drive and occasionally a quick spirited drive. Any input would be great. Thank you.

chuckc0313

iTrader: (1)

I run a gs aos and haven't had any trouble. I don't burn a drop of oil and I'm stage 2+ Running 24 psi. I have a new red gs aos Im willing to sell. Pm me if you're interested.

Krang

iTrader: (14)

GS AOS is fairly worthless to be honest, there simply isn't enough surface area for the oil to separate from the air. The Crawford unit absolutely works, and the yellow sludge buildup is minimal. Very easy to clean out with a little gas every year or so.

If you get an AOS, Crawford. You really don't need one for your power levels and type of driving though, but it's something shiny to have in your engine bay.

moto96793

iTrader: (8)

that's actually the only AOS I've haven't heard complaints about.

joejoe69

iTrader: (2)

Any good AOS is better than no AOS (or GS AOS). You don't want ANY oil going into your intake and trust me, stage 2 WILL definitely push oil out of your crankcase and back into your intake.

I've installed all AOS' except IAG's but based on what I read and see, I can break it down for you:

Grimspeed AOS

Pros:
-Cheap
-Easy to install
-Easy to service/clean
-Retains PCV and vacuum return for emissions and piston ring seal

Cons:
-Crankcase pressure overcomes inferior baffle, won't catch all oil
-No heater option; prone to condensation from cold weather or short drives


Crawford AOS V2

Pros:
-Moderate installation difficulty
-Welded unibody design; less parts
-Heater option to prevent sludge
-Vacuum return for emissions

Cons:
-Expensive
-Fairly large; takes up some room
-Can't service or clean due to unibody
-Paint flaking from inside
-Single baffle still lets oil through under high boost or hard cornering
-Still sludges even with heater option
-Deletes PCV for track use; ring seal possibly compromised under high boost applications


Perrin AOS

Pros:
-Excellent triple baffling; catches oil very well; no oil in intake hose
-Heater option for condensation prevention
-Serviceable/cleanable
-Retains PCV and vacuum return by default for emissions and piston ring seal, but can be deleted for track.

Cons:
-More expensive
-Hard to install for some
-Leaks externally if not installed correctly
-Uses cheap plastic fittings and requires teflon to seal


IAG AOS

Pros:
-Looks very nice (polished or wrinkle black/red)
-Semi unibody; combination of welded barbs and flared fittings
-Large surface area for separating oil molecules from air
-Heater option
-Can choose between non-PCV or PCV option for emissions or ring seal

Cons:
-Most expensive
-Hard to install
-Very large; takes up alot of space
-Uses single baffle and relies only on large surface area and crankcase pressure for separating air; not always ideal but that's what IAG claims.
-Deletes PCV by default (PCV version is available)
-AOS outlet hose is routed below car by default, next to downpipe because racecar and is emissions and fire prone if blowby is extremely high (Vacuum is available with PCV version)

You can draw your own conclusions but pick which one suits you, as there is NO perfect AOS out there.

FL4TBANGR

iTrader: (1)

thanks for that, very informative! My biggest worry is the yellow sludge making its way back into my intake or motor. That makes me feel I'm buying a part to potentially harm my engine. Thoughts?

joejoe69

iTrader: (2)

Yellow sludge is the least thing to worry about here in Hawaii because our climate is too warm for it to form. It mostly forms in climates close to or below 0° and such. But short drives can also increase temp deltas as the motor is hot while the AOS is cold, forming a little condensation. Anyway, like I said, highly less likely for us in Hawaii, but it's still a piece of mind to use the heater option just in case.

Intake oil sludge is what you should be worried more about and I highly recommend running an AOS especially if you're making power beyond the limits of stock. Remember, you're forcing more presssure in your engine. That means oil blowby will increase, as well as the chance for detonation.

FL4TBANGR

iTrader: (1)

Thanks joejoe69 I just bought a Crawford AOS through the group buy on NASIOC. I appreciate it!

Island Style

iTrader: (66)

Hmm...I've run single and double oil catch cans on my sti...checked on multiple occasions with very minimal to no oil collection...(Cusco Catch Cans)...I tried the GS AOS...not much there either...

Not sure if its worth the cost...

FL4TBANGR

iTrader: (1)

Ahhh that sucks to hear. the Crawford AOS just arrived yesterday. Well I guess it can't do no harm.

Island Style

iTrader: (66)

They definitely have "bling" factor in the engine bay...can't hurt either.

Eh...I gotta admit...the dual Cusco Catch cans did make my engine bay look nice...only thing bad...it seemed like everytime I needed to do something...I always had to remove those dang buggers...got to be a real pia

I can remember saying...oh, I need to clean up that area...then the thought of removing the catch cans (which were custom and very difficult and time consuming to remove) came to mind...bleh...eventually it was cleaned up...but at the cost of my patience...