Alternatives to catch cans: Air Oil Separators

[Huffer]

This applies to both FI and NA applications!

Air Oil Separators work like catch cans, but without the need to empty the catch can OR refill your oil pan.

We all know that during the combustion cycle that oil vapors and "blow by" are typically recycled by the factory system INTO the air intake tract. This is bad for several reasons, it contaminates the air intake and creates problems that Grimmspeed list such as:
1) reduced fuel octane 2) higher chance of engine knock(detonation) 3) worse emissions 4) higher oil consumption.

Below are links to two AOS add-ons, one from Grimmspeed and one from Prova, being supplied by RallySportDirect:

https://www.grimmspeed.com/catalog/prod ... cts_id=191 (https://www.grimmspeed.com/catalog/product_info.php?cPath=91&products_id=191) RRP $299.99
https://www.grimmspeed.com/images/product_images/aos_300_1.jpg

http://www.rallysportdirect.com/shop/pr ... -4057.html (http://www.rallysportdirect.com/shop/prova-subaru-air-oil-separator-p-4057.html) RRP $419.99
http://www.rallysportdirect.com/shop/product_thumb.php?img=images/AO1.jpg&w=200&h=200

Install thread by RallySportDirect for the Prova (also aimed at NA cars):
http://forums.nasioc.com/forums/showthr ... 782&page=2 (http://forums.nasioc.com/forums/showthread.php?t=1768782&page=2)

These are for people who do NOT want to mess around with emptying catch cans, and who want a clean, professional look to their engine bays.
Both models have some differences but both do roughly the same job.

The difference between the Prova AOS and the Grimmspeed model:

Why the GrimmSpeed AOS over other AOS products?
A: The GrimmSpeed AOS allows you to separate the vapors from both the heads and the crankcase. Others on the market only allow you to separate the vapors from the head. Also, our AOS allows you to retain the OEM PCV Valve. Being that it allows you to do both of these things at the same time makes it the most complete AOS on the market.

A possibility would be to modify a catchcan to allow it to return oil to the oil pan directly - which then makes it an AOS anyway.

[ben g]

ahh wtf i just ordered a catch can two days ago =/

[d1giPhux]

wow those prices are redic. thats insane!

[StatGSR]

yea those are a little much since u can get a moroso AOS for 100 bux.

http://www.jegs.com/i/Moroso/710/85471/10002/-1

[Huffer]

yea those are a little much since u can get a moroso AOS for 100 bux.

http://www.jegs.com/i/Moroso/710/85471/10002/-1

https://sl-i.net/FORUM/images/imported/2010/01/71085471-1.jpg

Yep, you can - but do you see the differences in the engineering? The Moroso one doesn't mount to a factory location, doesn't come supplied with hoses, and doesn't offer the "clean install" that the Grimmspeed or Prova ones do. That's why the higher price tag, because you're paying for a specifically engineered product.

The Moroso one looks like a hand-welded canister too...

[d1giPhux]

Yeah.. you can also buy giant chrome rims and paint your car electric orange too.. because it 'looks better'. Bah.. not worth $420 bux.. what a waste of money.

[rougeben83]

honestly, if youre getting a ton of blow-by that youre catching so much junk in your catchcan/aos, there's something wrong with your engine or motor oil. Even with daily blasts to redline, my modified wrx motor barely loses any GC oil between oil changes (3-4k miles).

[Huffer]

d1gi - well sorrreeee for attempting to spread some knowledge amongst the fraternity. Geez.

rouge - I think the point of an AOS is that every factory system introduces blow-by back into the intake - which is bad anyway, right? - so the AOS takes that out of the equation. And the other point of an AOS is to remove the inconvenience of ever having to empty a catchcan.

I'm not disagreeing that $3-400 for an add-on seems like a ridiculous use of money... but there are some out there who can personally justify it.
Just like how d1gi can justify the time and effort to retro fit heated mirrors, whereas I won't.

[rougeben83]

d1gi - well sorrreeee for attempting to spread some knowledge amongst the fraternity. Geez.

rouge - I think the point of an AOS is that every factory system introduces blow-by back into the intake - which is bad anyway, right? - so the AOS takes that out of the equation. And the other point of an AOS is to remove the inconvenience of ever having to empty a catchcan.

I'm not disagreeing that $3-400 for an add-on seems like a ridiculous use of money... but there are some out there who can personally justify it.
Just like how d1gi can justify the time and effort to retro fit heated mirrors, whereas I won't.

I know what you mean, I've seen an STI with one of those prova pieces before...he ended up selling it because he needed money :lol: I'm just saying for the price, you can spend your money better. I just want to clarify that these types of devices are only meant to catch whatever bit of oil happens to escape into the breather/pcv lines, not necessarily a way to fix any kind of oil consumption issue...

[d1giPhux]

I'm just a hater for things that are overpriced i guess.. :lol:

[StatGSR]

https://sl-i.net/FORUM/images/imported/2010/01/71085471-1.jpg

Yep, you can - but do you see the differences in the engineering? The Moroso one doesn't mount to a factory location, doesn't come supplied with hoses, and doesn't offer the "clean install" that the Grimmspeed or Prova ones do. That's why the higher price tag, because you're paying for a specifically engineered product.

The Moroso one looks like a hand-welded canister too...

clean install? it replaces the 710 cap! it would look retarded.... id rather tap my oil pan and hide the AOS entirely.... and on noes they dont include $2 worth of hose! what will i ever do! :lol: :wink:

[StatGSR]

and as u said its basicly a catch can with a drain, so you can go out, buy the ebay one. drill a hole in the bottom, add a fitting and call it a day.

[Huffer]

Stat - You have to admit the Grimmspeed or Prova items look a LOT more factory than your Moroso example. I'm not crapping on it either - but you cannot compare that construction to the very obvious R&D time spent on a CAD/CAM package that Grimmspeed/Prova have.

Anyway - it was just an "alternative" to the catch can thread. Forget I even started it!

[StatGSR]

they look nice as a piece, dont get me wrong, i think they would look dumb when actually mounted tho. you could mount the moroso or a modified ebay can where it would work and never be seen. those 2 have to be mounted at the 710 cap, which is frankly kinda out in the open and i still feel the price is unjustifiable for either one.

Also i have known Mr. Grimm (justin) for about 4 years now. and i am happy he has had great success with grimmspeed. i think its a clever idea, but i mean the hardest part about creating that part in cad would be getting the threads right for the oil cap.... the rest could be knocked out in about an hour if your any good with a program, a day at most, so the expense shouldn't have been in the design. Just trying to figure out where the extra cost was, might have been in prototyping or something i guess.

Sorry its just the engineer in me taking over.....

Edit.

it does look ridiculous!!! and is blocking off the dipstick...nice
http://www.grimmspeed.com/images/product_images/aos_installed_6.jpg

[Grafton]

after seeing the stuff that my catch can "catches" i would never want that stuff back in my motor...
and my catch can was $20 and i am using my stock pcv valve

to each their own...

[Huffer]

Stat - if you read the thread on RS25, Justin addresses that issue re: blocking the dipstick. On that particular car the AC unit was removed and the top was rotated around.

And I agree with most if not all of your points - but yes Grafton, to each his own.

Also Grafton - the stuff you caught came from your motor - and an AOS simply drops used oil back down into the pan - if you have anything larger than vapor in your catch can then your oil filter isn't doing it's job and no amount of AOS activity is going to save your engine.

FWIW, I wouldn't spend $3-400 on one of these either. I'd much rather buy tires. But it has been a fun discussion!

[d1giPhux]

wow.. got a full on discussion going here. thats dope. I would actually LIKE an oil catch can like that or 'AOS'.. but yeah, i just had to laugh at that price a bit. They do LOOK nice.. thats for sure.. well.. maybe not that sea squid up there ^ but if set up proper bet it could look decent, and the concept is great. I'm sure they did put a lot of time into it.. but still, that price is killin me just for some recycled dirty oil.

[Huffer]

I agree digi! For the vast majority of us a cheap $20 catch can is going to work great. But with every product you have top, mid and low end price points. Just like with wheels, tires and all that.

:)

[GrimmSpeed]

lol, thanks for the local support :-?

I don't think they look dumb at all when mounted..personally i think its the cleanest looking out of all the aos and catch cans out there.

honestly, if you think you could pound out our design in an hour, you are very mistaken. we've been designin, testing, redesigning, etc etc for over a year now.

it doesnt block the dip stick. in the picture of my car below, i don't have the a/c unit so i put the aos facing straight left. most people will have the aos rotated clockwise a bit so it won't be covering the dipstick.

Thanks again for the support Kyle :smt023

Justin


they look nice as a piece, dont get me wrong, i think they would look dumb when actually mounted tho. you could mount the moroso or a modified ebay can where it would work and never be seen. those 2 have to be mounted at the 710 cap, which is frankly kinda out in the open and i still feel the price is unjustifiable for either one.

Also i have known Mr. Grimm (justin) for about 4 years now. and i am happy he has had great success with grimmspeed. i think its a clever idea, but i mean the hardest part about creating that part in cad would be getting the threads right for the oil cap.... the rest could be knocked out in about an hour if your any good with a program, a day at most, so the expense shouldn't have been in the design. Just trying to figure out where the extra cost was, might have been in prototyping or something i guess.

Sorry its just the engineer in me taking over.....

Edit.

it does look ridiculous!!! and is blocking off the dipstick...nice
https://sl-i.net/FORUM/

[StatGSR]

^ well im glad to hear you guys put in the time with the piece. it is a nice looking finished product, and i was happy to find some prototype pics from testing after some additional research on it. sorry about the cad comment, 3D cad work has always just come natrually to me and i miss doing it.

I can honestly say its not something i would get but then again im a buget builder and willing to spend the extra time to figure it out myself. others are willing to spring the money to get something convenient and simple and thats where you guys will get your sales (and from what i saw on the nasioc GB you guys did pretty well). I always think most people are similar to me, but i realize more and more that lots of people dont wont more than simple projects with thier cars nowdays.

i hope you know it was nothing personal, but im still going to speak my mind on any product regardless of who is making it.

and yea i did find some other pics where it didnt block the dipstick, that just happened to be the first one i found. my bad

Keep up the good work justin and like i said i am very excited with how successful you have been with grimmspeed.

btw where the hell were u last weekend? we missed u and your girly drinks!!!! :wink:

[Reason]

I always laugh when people cry about a price of a product and they don't take into account of EVERYTHING that is involved from ram material to a shelf product. We had this decision before and I'm not going to get in depth of it again. But this is a product you don't need, so is any other aftermarket performance part. You don't need any of it. But we want it because it's our hobby. This is a very exspensive hobby. You can buy a pair of Keds, or buy a pair of Jordans...

This is a very interesting product. Oh yea and another thing that is funny is the people say why would I want dirty oil recycled back into my system? Well change your damn oil more often and it wont be so bad and you wont have that problem. I rather use the oil instead of running low or having to add oil every x amount of miles.

[99gtlimited]

hardest part about creating that part in cad would be getting the threads right for the oil cap
https://sl-i.net/FORUM/

most CAD platforms these days have all known thread specs already loaded (both left and right hand threads) so all you would really need to do is to figure out exactly what the specs of the thread for the oil filler cap are, which would just require taking the cap off and counting the threads in one inch and knowing the OD of the thread.

[99gtlimited]

This is a very interesting product. Oh yea and another thing that is funny is the people say why would I want dirty oil recycled back into my system? Well change your damn oil more often and it wont be so bad and you wont have that problem. I rather use the oil instead of running low or having to add oil every x amount of miles.

This is what came out of my catchcan: mostly oil with a little water in a gross milky slurry. I don't think I would want this going back into my oil pan...

https://sl-i.net/FORUM/images/imported/2010/02/0131002031-1.jpg

[tougemachine]

you can just do it Millwright style and make your own catch cans to suit your own engine bay...

i have access to mills, lathes, welders, and all sorts of stuff i wold need to make some pretty sweet catch cans of all sorts...hint hint... :lol:

[Brockley]

Just my $.02- I've seen this setup before, and if it were on my car, I would not want the super long hoses running across the engine bay. Why not mount this next to the Throttle Body, and have a single hose running to the Oil neck?

http://filebox.vt.edu/users/vhogan/aos_installed_6.jpg

[ScaryFatKidGT]

Grimmspeed makes good stuff I do like how most of there stuff mounts to existing locations and has been tested not to interferer negatively with anything; boost controllers, phnematic spacers are the perfect size, ect. how ever as stated before for $400-$20=$380 il empty a catch can

P.S. after that pic im getting a catch can

[Grafton]

thank you for posting your catch can stuff, looks like mine when i empty it mostly water defintly dont want that in my oil i would like to hear what grimmspeed has to say about that

[99gtlimited]

phnematic spacers are the perfect size

you mean Phenolic spacers? :grin: :grin:

[ScaryFatKidGT]

phnematic spacers are the perfect size

you mean Phenolic spacers? :grin: :grin: yeah yeah it was like 3am lol