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Cold Air Intake

37K views 20 replies 12 participants last post by  RcrsWetDream 
#1 ·
Does a 2009 WRX run ruff with an aftermarket air intake?
 
#4 ·
Here is a quick rundown on mods: http://www.wrxtuners.com/forums/f51/_the_-wrx-modification-guide-complete-4007/#post26112

CAI info:
"I fully understand the reasoning behind this mod in some WRX owner’s eyes. In most other cars a good Intake is worth 5 to 10 hp, however not so in the WRX. It does change the turbo spool sound to add a quite nice scream at full boost, however can potentially damage your engine, not to mention little to no power gain. The stock intake (minus the resonator, See Exhaust for diagram) is capable of 325 hp. Intakes simply lean your car out (More Air Less Fuel) to gain power and can seriously hurt your engine and turbo if installed before engine management and injector upgrades."

Unibomber's Intake FAQ: http://forums.nasioc.com/forums/showthread.php?t=477393

Other Guides you may be interested in: http://forums.nasioc.com/forums/showthread.php?t=533787

Bottom line is that you probably don't need to upgrade your intake unless you are over 300+ whp (conservative) which you are not near in a stock WRX (or even at stage 2). If you want one anyway buy from a trusted manufacturer and get a tune so you don't run lean.
 
#14 ·
Here is a quick rundown on mods: http://www.wrxtuners.com/forums/f51/_the_-wrx-modification-guide-complete-4007/#post26112

CAI info:
"I fully understand the reasoning behind this mod in some WRX owner’s eyes. In most other cars a good Intake is worth 5 to 10 hp, however not so in the WRX. It does change the turbo spool sound to add a quite nice scream at full boost, however can potentially damage your engine, not to mention little to no power gain. The stock intake (minus the resonator, See Exhaust for diagram) is capable of 325 hp. Intakes simply lean your car out (More Air Less Fuel) to gain power and can seriously hurt your engine and turbo if installed before engine management and injector upgrades."

Unibomber's Intake FAQ: Intake FAQ: Read if you are thinking of buying one! - NASIOC

Other Guides you may be interested in: Unabomber's Manifesto - NASIOC

Bottom line is that you probably don't need to upgrade your intake unless you are over 300+ whp (conservative) which you are not near in a stock WRX (or even at stage 2). If you want one anyway buy from a trusted manufacturer and get a tune so you don't run lean.
Thanks alot for the info.













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WRX Performance Chips
 
#5 ·
That's true, but that logic applies more to 02-07 models (they benefit best from a drop-in air filter and/or silencer delete mod up until ~300 hp). The 08+ models can benefit from an aftermarket intake since their design is pretty restrictive.

Remember though, you can't run an FMIC with a cold air intake - if that's in your future - but you can with a short ram. Something to think about...
 
#6 ·
I have read a lot of mixed opinions on this. There was a Car and Driver article that said that with the K&N they got 17hp. AEM claims 13hp gain from theirs. Overall it definitely seems like it could possibly add power to the 08+. Going back to the OPs first post, he is asking if it will "run ruff". I think most of us would recommend a tune at least. One of the reasons I didn't take the C&D article seriously is that it suggested you would be fine to install either the K&N intake or a Magnaflow TBE without a tune but not both. That seems really counterintuitive.

So, you can try an intake but I think you should definitely tune for it and I wouldn't be surprised if you see minimal gains.
 
#7 ·
Oh yeah, I definitely agree, a tune is great after adding almost any power-related part. However, for the sake of this argument, I think he's trying to ask: "will adding an aftermarket intake to my 09 WRX just by itself without a tune make my car run rough - and by rough, I mean how it would most likely tend to run after adding a fully vented atmospheric blow off valve without a tune" ...if that's the case, the answer is no, it won't run rough by just adding an intake. Yargggh, this is getting complicated fast.
 
#8 ·
Until you get to 350 wheel horse power, it's not even worth it (so goes the word on the newer subies). running lean is trouble for sure and the drop in panel filter is a nice piece. I know of a few members who like how the stock box runs with a few more holes drilled in it...

Unless you just want to hear the turbo's buzz/whine more, I wouldn't recommend getting one until you've done all the supporting mods like; turbo back exhaust, injectors, fuel pump, and possibly the top mount or a front mount intercooler. Of course you would need a pro tune with such things. Depends on where you want to go with your car... There's nothing wrong with the stock box at all and I like that you can't get water in it unless you drive off a bridge into a river or the like. I put the drop in filter and just cleaning it twice paid for itself instead of replacing the paper b/s ones, and it flows better. 'They' claim there's a small gain in hp, but I can't prove that and don't really care to. It's just nice to have and won't set off the maf sensor.
 
#15 ·
I put the drop in filter and just cleaning it twice paid for itself instead of replacing the paper b/s ones, and it flows better. 'They' claim there's a small gain in hp, but I can't prove that and don't really care to. It's just nice to have and won't set off the maf sensor.
What kind of filter did you use? I have a K&N in my Saab and plan to put one in my 2010 WRX. Is there a better one to use?
 
#11 ·
That would have to be some serious b/s in my book, but hey I'm not an AEM employee nor do I own one. If it does that huge of an increase and your car still lasts 6+ years with it on then I'm buying one! LoL.
 
#16 ·
I bought the Perrin drop in just because I bought it at the same time as the single piece down pipe. The K&N should be just as good if not better from what I hear. It's way better than buying new paper ones!
 
#17 ·
just got my car back, dropped in my AEM CAI and let me tell you, there is a noticeable difference. Running XPT Stage 2, which has a tune specific for this intake. I had a nasty exhaust leak that has been sealed as well but the car just feels like it accelerates easier. Throttle response is alot quicker, which is the opposite of what i thought would happen with the extra piping. It also helps at the higher rpms and the drop in boost is less noticable. just seems smoother.
 
#18 ·
I just ordered an AEM CAI and i have read on different sites that it wont mess up the MAF reading because its the sam size in diameter as the stock one. oh and as for the gains, on a wrx they say its anywhere from 13-19 HP and for the sti its anywhere from 25-38 HP. I cant prove it, its just what i read.
 
#19 ·
lean condition

The check engine light will come on if there is a lean condition so you will know about it. The ECM will compensate and add more fuel if more air is being introduced. There is a certain percentage that it will compensate, and once the percentage is exceeded then the check engine light will come on. Then you will have a lean condition code. Thats my theory from someone who has spent to much time in school to learn all this.
 
#20 ·
Headed down to the shop after work to get the AEM CAI for my 2010 WRX Hatch. I will keep you updated as well. Doubt the power increase they claim, but there is only one way to find out. First performance mod to the week and a half old hatch...only thing I have done so far is limo tint the backs, dark on the front. Looks pretty sick!
 
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