Tag Archives: mods

Air Oil Separators – Not All Created Equal

I’m thinking on adding an air oil separator (AOS) to my wishlist.  It’ll help keep the oil out of my IC and intake and keep the car from experiencing detonation by preventing any condensation from making it into the engine. There are arguments on if this item is even needed on a Subaru (or any blown) engine (see here). There’s quite a bit of AOS makers, too.  I’m going to link each one, but keep in mind that the links may break as the web designers move their products around their web pages:

  • Grimmspeed – this appears to quickly-installed product, but I’ve seen bad reviews of it; there are conditions that will cause blow-by, even with this AOS.
  • Moroso – this is a small dual can variant – $275; they have $350+ variants as well as variants that are $100 less.
  • Perrin – this is a nice unit; I like the fact that I could theoretically pull the drain hoses and see what the oil condition looks like after it has worked its way through the separation process.
  • Crawford – from their website: “Largest internal volume (.75 liters) on the market. This volume is imperative to the effective separation of the oil from the air.”
  • iAG – they’ve a LOT of science-like info on their site regarding this product, but I’m not sure that will be enough to sway me.

I may have missed a few, but those are the ones that jump out at me.  Plus, it seems like the aftermarket is flooded with tuner interpretations of the AOS concept. Note that almost all of them are in the $350-$375 range.  That’s a lot of cash, but apparently they aren’t all created equal. Grimmspeed’s doesn’t work all that well on engines that crank out 350-400 HP, but it’s cheaper than most of the others.  Apparently, they don’t take well to high G maneuvers and they also tend to be more of a street application (low HP and street with no hard street driving).  There have been reports of significant blow-by occurring with the Grimmspeed AOS.  I found a good NASIOC forum thread here that describes this issue and even has Grimmspeed feedback. Crawford’s and Perrin’s apparently work very well on high HP applications. The Moroso AOS appears to also be a good candidate and has many options.  They come in single and dual container configurations.  With the dual container option, you can opt for large or small containers.  The containers can be obtained with powder-coating too.  The thing I’m confused about with the Moroso is that they appear to be more of a catch-can solution.  They will not direct separated oil back into the oil supply.  They have to be periodically emptied and the from my understanding, the they don’t really separate the oil from condensation…the gunk is really something you don’t really want to reintroduce to your oil supply. There’s also the thought that with the general thought behind the AOS concept, you shouldn’t really be redirecting separated oil back into your engine’s supply.  The thing is, these aren’t considered cat cans.  Catch cans just catch any blow-by that occurs.  They have to be maintained…you don’t want them to be full and you have to throw out any gunk they catch.  With an AOS, there’s a separation mechanism and the idea is that once the oil is separated and de-condensed, it should be OK to put back into the oil supply, but I’ve yet to see vendors/makers provide evidence that the oil that is separated is clean and can be reintroduced to the engine’s oil supply.  So, I’m torn between buying an AOS and buying a catch can that I’ll have to maintain. I’m leaning toward the iAG (one of the most expensive) or the Moroso (because it looks good and because it’s cheaper…but it’s just a glorifed catch can…I really don’t think they are true AOSs).  iAG swears that they’ve stopped the issue of condensation, but they haven’t provided any hard evidence.  I’d hate to spend $380 on an AOS (any AOS) only to find that they’re putting gathered gunk back into the engine. Oh, and what’s the difference between an AOS and catch can?  The AOS separates the oil from any condensation and returns the oil back to the oil supply.  A catch can only catches it, it has to be periodically emptied, and there may be more than oil that’s captured.  And note that there are some $300 catch cans.  That’s a pretty ridiculous price for a catch can but apparently Mishimoto sells catch cans in that price range. Lastly, for those located in areas where there are strict emissions testing, an AOS might not be a good thing.  Remember, not only are there visual inspections that some states require (an AOS might not pass a visual), but there’s also the actual sniffing/testing…an AOS might cause a test failure.  I’m not 100% but I wanted to forewarn people, because the PCV is an emissions part.


UPDATE: Regarding the Moroso, I did a bit more research and found some clarification on the Moroso unit (regarding if it’s a catch can or actual AOS):

Q:  The title says it’s an Air Oil Separator, but the description sounds more like it’s an Oil Catch Can since it has to be drained. Which is it?

A:  Its a separator in terms of it breaks down the fumes much more efficiently compared to just a catch can.

If that’s the case, then the oil that it catches can be poured back into the oil supply (sounds like, at least).  I found the answer here, under Questions (it is the second question…the questions aren’t linkable).  And note that these do indeed require maintenace (ie, they have to be periodically drained/cleaned).  Some variants have drain petcocks, and others can be removed from the mount.

Aftermarket Heat Shields

I posted earlier about my turbo heat blanket research and my findings.  I mentioned in that post that I would look at aftermarket heat shield solutions.  My plan is to use both a good turbo heat shield and the turbo heat blanket.

My choice will be one of the following:

Nameless Performance Downpipe Heat Shield

CB Titanium Heat Shield


The Nameless Performance example is normally $85 (subject to change, obviously) but there’s also the option of a ceramic coating, which adds $40 more to the cost.  There are also free color options.

The CB example is fully titanium and is $4 more than the Nameless version.

I’m obviously biased since I’ve several Nameless products on the car already (a Nameless product would better fit the current motif, and with the option to add different coloring, I can better coordinate a desired look).  I’ll more than likely go Nameless, but I wanted to mention the CB option, since they’re close in price and because titanium is one of the more exotic materials to use.

Nameless Performance Cold Air Intake Installed!

If you remember, I received my Nameless Performance cold air intake a few weeks ago.   I didn’t plan to install my Nameless Performance cold air intake this weekend but I ended up doing just that.

I had a bit of a time trying to figure out how to remove the stock air box and how to install the new CAI.  Only two bolts hold the stock air box in place.  The bolts were difficult to reach but weren’t too difficult to remove.  It’s reinstalling the stock air box that might be troublesome, IMO, because rethreading those bolts back on might take awhile.

In hindsight, I think I probably would’ve been better off getting the Cobb SF intake and airbox.  I still might look into going that route, but I absolutely love the way the NP intake looks in my engine bay.  I sorta wish I’d been able to see the different color options (that wasn’t available when I ordered mine, but it’s on the NP product pages now….they’ve many color schemes depicted.

The install of the CAI wasn’t all that bad.  It’s a tight fit and the product uses the same mount points as the stock equipment, although you have to remove a bracket.  I had to search on the web for a picture of a mounted NP CAI to see how to mount it.  It comes with no instructions.  Fortunately it didn’t take me all that long to figure out and install.  It took me 1.5 hours to install, but that’s only because I kept stopping to take pictures and video clips, and I kept double-checking my work (since I didn’t have instructions).

Here’s a picture of my extremely dirty stock air filter (I don’t think the dealer replaced it like I asked them 9 months ago and the car’s barely been driven since then).




Here’s a shot of where the stock air box used to be:



Here’s the close-out and MAF housing that I managed to figure out how to mount:



Here’s where I mounted the MAF sensor (it only fits this way…I suggest you mount it before mounting the close-out…that way, you don’t end up dropping the little screws in the engine bay):






I can now hear turbo spool-up…it is very noticeable.  I can also hear air rushing into the intake.

Note that this CAI requires a tune.  This unit is compatible with Cobb’s AEM maps.  I’m currently using the Cobb OTS Stage 1 91-octane AEM map.  I’ve logged a few miles with pulls included…the logs are kosher.

There’s a slight hesitation at throttle tip-in from idle.  It only happens from idle and it almost sounds like the throttle plate is fighting a vacuum, but I’m not sure that’s possible.  There’s no boost leak (I’m hitting peak boost without issue).  I’m trying to determine what’s going on.  I wonder if this is just a map issue that a tuner can tune out.

Oh, and here’s a video:



Nameless Performace CAI has arrived!

20140422_151637_HDR 20140422_151718_HDR 20140422_151741_HDR 20140422_151822_HDR 20140422_151507_HDR 20140422_151554_HDR 20140422_151614_HDR

This is the Nameless Performance cold air intake (CAI) that I ordered a month and three weeks ago.   I’ve been waiting for this a long time.  At first, I was upset because I thought that most of this was pre-built, but after making a complaint to Jason (of Nameless), he e-mailed me stating that they were almost done building it.  I did a mental double-take.  Then, when I received it, I got a good look at the craftsmanship…it’s good enough to where I can mount it over my fireplace (I’m not joking).  It’s almost a work of art.  The close-out is powder-coated.  If I’d have known it would look that good, I’d have maybe chosen another color.  I opted to have the MAF housing as black in color.  Overall, it looks great!

I’ll probably end up mounting it a week before my protune is scheduled.  No, this CAI doesn’t need a protune, as it is compatible with Cobb’s AEM OTS tunes (although, a protune would be more efficient/safer).    If I could, I’d get the car dyno’d and tuned before the parts are mounted and afterward, but I can’t/won’t.  I’m also still mulling over getting an e-tune.  I’ve a few e-tuners in mind, but will need to get the low RPM stumble fixed (there’s an online mod how-to here).

Cold Air Intakes by Nameless Performance

 Nameless Performance Cold Air Intakes for 2008+ WRX/STIs, coming January 2014.





After seeing this FB post, I’ve decided to purchase a Cobb AP and this intake (provided it is reasonably priced, ie $200 or so).  I’m actually still on the fence about the AP purchase, but looking at that FB post and the dyno chart posted by Nameless, the gains are really strong (9HP and 34TQ, peak measurements), you can’t really argue with that.  And Nameless even posted a chart awhile back that showed similar gains with just the damned axleback…crazy.  Add the Nameless axleback, the intake, and a safe but good protune, and I’d be close to 300TQ and maybe 260HP.  And I suppose if I get in over my head (I’ve done the modding game before…after awhile, it got tiresome, and that was before my kids arrived), I can always remove the bolt-ons and revert to an OTS (or run stage 1 without mods & with safe protone, which would still give me gains).

RRE results – tuned 2002 Subaru WRX

RRE states:

An all stock 2002 WRX comes in around 180HP on our dyno. This one with full exhaust, intake, and RRE 3 port finished at 245 and 266 lbft of torque at 17psi peak after our tune.

That is a pretty damned good tune.  That’s about the same power as a stock 2011 STI.  Wow!

Post by Road Race Engineering (official).