Grimmspeed AOS

[Razgeiz]

I have installed this product myself on my 13 STi and am very pleased with it. The $250 is hefty however this piece is very solid and looks great under the hood. It also gets rid of the ugly yellow oil fill cap which I personally hated. The parts are all top notch and I do enjoy the feature that it returns the oil back to your supply. No more oil loss at all! Also I didnt install this until a few thousand miles into the car and I ended up swapping the turbo inlet and found old caked oil in there... I recently pulled my new inlet that was installed after the AOS and bam no oil like crap built up!

I cannot say enough about this piece and would recommend anyone to buy it and to not let the price alone scare you away!

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[mmetalmilitiaa]

Bought one of these about a year ago. Recently replaced it with a catch can setup. The grimmspeed aos is a cool idea... But it doesn't work in my experience. Wish I had saved my money.

If anyone still wants one for some reason, PM me and I'll give you mine for dirt cheap... Haha.

[GrimmSpeed]

Originally Posted by mmetalmilitiaa

Bought one of these about a year ago. Recently replaced it with a catch can setup. The grimmspeed aos is a cool idea... But it doesn't work in my experience. Wish I had saved my money.

If anyone still wants one for some reason, PM me and I'll give you mine for dirt cheap... Haha.

What kind of issues were you having with it? From our testing we've found that it works great in the advertised manner.

Mike

[Acejam2k]

Originally Posted by GrimmSpeed

What kind of issues were you having with it? From our testing we've found that it works great in the advertised manner.

Mike

If you go around a corner quickly, oil comes up the crankcase breather hoses and oil filler neck. Since some of that oil is coming from the bottom up, it then gets sucked directly into the turbo inlet.

That seems like a pretty big design flaw, and probably the reason why many people are removing their Grimmspeed AOS's. In most cases, it seems to do more harm that good.

[GrimmSpeed]

Originally Posted by Acejam2k

If you go around a corner quickly, oil comes up the crankcase breather hoses and oil filler neck. Since some of that oil is coming from the bottom up, it then gets sucked directly into the turbo inlet.

That seems like a pretty big design flaw, and probably the reason why many people are removing their Grimmspeed AOS's. In most cases, it seems to do more harm that good.

Yeah under sustained high G cornering oil can be forced up those ports. We typically recommend the AOS for people who daily drive or drag race there vehicles. It may not be the best fit for your car if you like to flog it around corners or track your vehicle/ auto cross.

Mike

[nevin95 LSi]

Just checking in.

My GS AOS been on the car for about 40k miles now, and it still works great!

It's a daily driven '02 wrx wagon with nearly 270k miles on the clock!

Oil useage is still a non-issue and I'm not an auto-xer or anything, so I haven't had any issues as some have had. I go drag racing a few times a year, but that's my only form of motorsport.

I recommend this part to all of my friends with wrx's.


Also, does this part exist for N/A cars? My '95 SVX could certainly use something like this, as it's oil useage is about the same as the wrx used to be before the AOS.

[GrimmSpeed]

Originally Posted by nevin95 LSi

Just checking in.

My GS AOS been on the car for about 40k miles now, and it still works great!

It's a daily driven '02 wrx wagon with nearly 270k miles on the clock!

Oil useage is still a non-issue and I'm not an auto-xer or anything, so I haven't had any issues as some have had. I go drag racing a few times a year, but that's my only form of motorsport.

I recommend this part to all of my friends with wrx's.


Also, does this part exist for N/A cars? My '95 SVX could certainly use something like this, as it's oil useage is about the same as the wrx used to be before the AOS.

Hey Nevin,

Thanks for sharing your results!

We did a bunch of testing on NA engines and weren't able to get adequate results. We believe this is due to the difference in crank case pressure/vacuum and the use of the PCV system.

Mike

[mmetalmilitiaa]

Originally Posted by GrimmSpeed

What kind of issues were you having with it? From our testing we've found that it works great in the advertised manner. Mike

I was having oil still reach my turbo inlet via the return line from the AOS. I even went as far as to put a small catch can in between the two parts to make sure it wasn't something else. The car is a daily driver and I do no "hard cornering" or anything like that. Also, the other thing that strayed me away is the coffee like froth that appears when it's colder outside. A little bit isn't a big deal, but when it's to the point where it has every hole clogged, that worries me.

It wasn't a lot of oil, but enough for it to defeat the purpose of using it in my mind. Perhaps it can't keep up with the cold start blow by of forged pistons? I don't know. Regardless, I love the products you guys out out. This one just didn't work for me.

[GrimmSpeed]

Originally Posted by mmetalmilitiaa

I was having oil still reach my turbo inlet via the return line from the AOS. I even went as far as to put a small catch can in between the two parts to make sure it wasn't something else. The car is a daily driver and I do no "hard cornering" or anything like that. Also, the other thing that strayed me away is the coffee like froth that appears when it's colder outside. A little bit isn't a big deal, but when it's to the point where it has every hole clogged, that worries me.

It wasn't a lot of oil, but enough for it to defeat the purpose of using it in my mind. Perhaps it can't keep up with the cold start blow by of forged pistons? I don't know. Regardless, I love the products you guys out out. This one just didn't work for me.

Hmm interesting. Was your PCV healthy and clean?

As for the froth this is normal in all engines. It's h2o, oil, and air all kinda gooping together. This would normally build up in different parts of the engine but out AOS gives it a place to build up and be seen on. Once the engine heats up this should all separate and clean up.

Mike

[CRX7]

Got it used for $120 shipped. Helped me clean up my engine bay vacuum lines on my EJ20G. Works great and doesn't take up space in the engine bay. Gives me a little extra piece of mind, so I don't have to check my oil level quite so often.

I chose this over the Perrin and Crawford setups as I don't want to go to the trouble of running extra coolant lines. I like the simplest solution and this works for most situations. I will check my oil level after autocrossing, but I've seen no issues with the corners I take daily driving.

EJ20g Setup:
AOS Intake Port 1: T your crankcase vent and PCV together, You will need a 3/4" to 1/2" converter for the crankcase vent.

AOS Intake Port 2: T your valve cover breathers together.

AOS Output Port: Connect to any pre-turbo vacuum port of sufficient size.

[TAJR02WRX]

I have had this AOS on my car for a about 20-25k miles, everything has been working as designed. I love how simple it is and that you can use the emergency lugnut wrench in the car to take off the AOS cap. The finished on the AOS is really durable and hasnt scuffed once yet. (I have to remove mine everytime I check my oil level, I kinda messed up on runnning the lines over top of it haha) I dont autox and dont plan on starting that anytime soon so im sure this AOS will last another 25k miles with no issues.

Thanks Grimmspeed! Keep the parts coming

[sc00ter]

I've been using this AOS for about 2 months now on my '11 STI. After reading others reporting issues with it feeding oil back into the inlet pipe with hard driving, I decided to throw some clear fuel hose on to monitor myself.

I do plenty of spirited driving in the canyons with considerable amounts of hard cornering, braking followed by heavy throttle. When I pulled the black tube off I didn't see a single trace of oil in it. After installing the clear tubing I took a drive up the canyons to visit my parents. I was harder on the car than I normally am to determine if more extreme driving would cause the issue many seem to be reporting. When I arrived to my parents I popped the hood and was happy to find no trace of oil in the AOS outlet line.


I don't do auto cross so I can't report on that. But for spirited driving with plenty of corners, I can tell you that the AOS is working perfectly fine for me.

[wrx43v3r]

I only DD my car. Never been to a track. I drive a 2.5 liter with 2.0 liter heads and a 16G turbo - nothing fancy. When I had my hybrid engine built, I had a grimmspeed AOS installed. With the grimmspeed AOS my car would smoke on startup 95% of the time. When I removed my intercooler, there was clearly oil in the piping. This product didn't work for me. I changed to an IAG AOS, and I haven't seen exhaust smoke since the changeover to the IAG.

I don't want to get into a legal battle with grimmspeed, so I'll leave it at that. But if they want me to post a more complete, not politically correct review of their product, I would be happy to do so provided their lawyers provide me with a signed letter absolving me of all liability.

[sc00ter]

An update to my previous post above (#387)...

I've now had the Grimmspeed AOS installed for 8 months at stage 1. During that period of time I only found a few traces of oil in the clear hose going back into the turbo inlet. However, last week I went stage 2 and replaced the clear tube with a brand new one. I have now found new oil in the clear tube multiple times.

I have not cornered hard at all and seem to still find oil coming up the filler tube and into the clear tube after a couple of 2nd and 3rd gear pulls. It's safe to say that this unit no longer works for me either. So I'm looking to do 1 of 2 things...

1) Ditch it and either go with a Moroso or IAG unit.
2) Keep it installed and put a JEGS catch can in the tubing between the AOS and the turbo inlet tube. (location pictured below)


Catch can unit I'm considering:

http://www.amazon.com/JEGS-Performance-Products-52205-Separator/dp/B007WWW6DI/ref=sr_1_9?s=automotive&ie=UTF8&qid=1423604670&sr=1-9&keywords=oil+catch+can


Install location: (Still unsure of how to mount it, but I'll figure something out.)



Thoughts?

[OA5599]

a can by the clear hose seems
like a pretty unique idea -

maybe the Grimmspeed is still working at a reduced capacity
and the extra catch-can might suck in the rest of the oil blowby

[sc00ter]

That's what I'm thinking.

On the plus side, this is essentially creating a make-shift 2 can system like some of the others you can buy.

However, on the negative side, I'm slightly concerned that adding another obstacle in the line might prevent the intake vacuum from sucking enough air back into the inlet. I'm not sure what, if any, issues this may cause with my tune.

EDIT: Screw it, I ordered the JEGS catch can. I'm planning on mounting it to the bolt holding the BPV to the TMIC. I'll report back with how it goes.

[sc00ter]

UPDATE: The Jegs catch can arrived 2 days ago. It was great quality but I simply couldn't find a good way to mount/install it that wouldn't look "ghetto". It required adapters to get a 1/2" barb from a 3/8" barb and the result just looked like a thrown together sub par plumbing job in the engine bay. To top it off, there just wasn't anywhere to mount it in a way that looked decent at all.

So I ended up doing some more research and it looks like people on IWSTI have been running into the same issue with the Grimmspeed unit spitting oil back up the "clean" tube. Those guys recommended using the Cusco catch can paired with the AOS to solve this issue.

It is designed with a bracket specific to the GR models to make it mount perfect and look MUCH cleaner. I ended up biting the bullet and ordering one. It will be here today. Once I get home tonight I'll get it installed and get some pictures of the whole setup.

http://www.rallysportdirect.com/Cusc...-STI-2008-2011


How does this relate to reviewing the Grimmspeed AOS?

Well, I can say that getting this unit to work properly, even at just Stage 2 levels with absolutely no track time or hard cornering, you need to go spend another $125 on a second catch can or build one yourself. To me, this is just unacceptable.

When all is said and done, I will have spent $400 on this whole setup (after returning the Jegs unit). I could have spent less than that and just bought an IAG, Crawford, Moroso, or Perrin unit instead and they would have worked without any additions or modifications.

I wish I could get my money back at this point. It's a shame that they keep selling the unit as is.

EDIT: For those curious, I got the Cusco catch can installed last night and below is a picture of the new setup. Unfortunately, Cusco's directions were in Japanese with extremely blurry pictures, making them practically useless. I found some English instructions but they looked thrown together with no pictures. Nothing I read gave ANY indication as to which port was the inlet and which was the outlet. I ended up basing my setup off of a couple pictures I found on Google, even though it does seem backwards to me...

[Odis]

Some thoughts on overloading this system (if the claims are true/accurate). Does anyone know if oil is running up the oil fill only, or vents only, or both, durning extended high g-load turns? Is it just turning to the right (most likely the oil fill)? If the oil is only coming up the oil fill, a removable baffle might solve the problem, because the oil spike is a short term event. Removable, so you can add oil. I like this AOS, but I can't quit hit the buy button.

[sc00ter]

I'd be curious to find out for sure. The catch can isn't the best solution, if you ask me.

[stevenkelby]

Originally Posted by sc00ter

I'd be curious to find out for sure. The catch can isn't the best solution, if you ask me.

Why not? What do you think the best solution is?

[sc00ter]

I mean, the best solution is to design the baffling in the GS unit so that oil has a MUCH harder time getting back up into the "clean" tube.

But aside from that, I'm really not sure what the next best solution is. The catch can works fine but with an additional cost of $100+ it just doesn't make financial sense to get the GS unit and a catch can. Might as well just go with one of the better designed AOS units at that point.

I went the catch can route because I already had the GS unit installed and it was a sunk cost for me. If I were doing it all over again I wouldn't even consider the GS unit.

EDIT:
I suppose I should also mention that after almost 2 months with the Cusco can installed, I'm seeing a good amount of oil building up in the tube from the GS unit to the Cusco can. The tube from the can to the air inlet is perfectly clean. I'm not seeing enough oil building up in the can that it is hitting the drain indicator, but it's only been about 2800 miles (I don't drive much). I'll see how many miles it takes for the can to need draining. But I will say the Cusco can is definitely putting a 100% stop to oil getting back into the inlet.

[REX_WGN]

good info, thanks for that

[ImDarkwingDuck]

I was considering an AOS soon. Good info in here.

[tehknikhal]

Originally Posted by sc00ter

I mean, the best solution is to design the baffling in the GS unit so that oil has a MUCH harder time getting back up into the "clean" tube.

But aside from that, I'm really not sure what the next best solution is. The catch can works fine but with an additional cost of $100+ it just doesn't make financial sense to get the GS unit and a catch can. Might as well just go with one of the better designed AOS units at that point.

I went the catch can route because I already had the GS unit installed and it was a sunk cost for me. If I were doing it all over again I wouldn't even consider the GS unit.

EDIT:
I suppose I should also mention that after almost 2 months with the Cusco can installed, I'm seeing a good amount of oil building up in the tube from the GS unit to the Cusco can. The tube from the can to the air inlet is perfectly clean. I'm not seeing enough oil building up in the can that it is hitting the drain indicator, but it's only been about 2800 miles (I don't drive much). I'll see how many miles it takes for the can to need draining. But I will say the Cusco can is definitely putting a 100% stop to oil getting back into the inlet.

I just noticed that I am starting to get build up in the middle tube as well (as I've been reading which is supposed to be the clean air tube) IS getting a catch can the only option? I've read mixed reviews before buying the GS AOS, but jump the gun anyway. I just want to make sure I got my money's worth, I've just recently noticed the two ends one towards the aos and one towards the air line with oil build up.

[sc00ter]

You have 3 options, really...

1) Remove the GS unit and go back to stock
2) Install a catch can between with the GS unit and air inlet tube
3) Sell the GS unit and buy one of the other units that doesn't have this issue.

I decided to go with the catch can because the GS unit was already installed and I knew the catch can would solve my issue. With my current setup, it solves the issue completely. So it is a valid option if you've already spent the money/time installing the GS unit.

However, if you want to do it "right", I'd recommend selling the GS unit and buying one of the other AOS units instead. I may actually go that route at some point, but I'm in no rush right now.