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FYI:Regarding the AEM Cold Air intake

2K views 11 replies 8 participants last post by  askjeffro 
#1 ·
I'm still tossing around the idea of installing one. However, I'm still leary about if it will damage the engine if a, "lean" condition is present. So I sent AEM an email with my concerns, the reply back was as follows.

Joe,

"We have no issues on our intake system, for your information our intake has passed Air Resource Board testing and was issued CARB E.O. and is now legal as of 8/2008."

So figured I let you guys know because some of you were waiting for the CARB approval on this CAI.
 
#2 ·
Very cool indeed, but remember the legal loophole. No concerns if only an intake installed. This statement is void and so is the CARB if other modifications are done to the vehicle.

Also note this: Leaner = more thorough fuel burn = hotter = less carbon emissions = pass CARB
 
#4 ·
Apon further pestering by me ::).
Here is the next response when asked about any, "Lean" conditions resulting from install.

"Joe,
We test all our kits on factory standards (stock boost), you should have no leaning issues. The testing that CARB does and approving it for use satisfies all your concerns. IF it would cause issues , they would not have approved it legal for street use.
Keep the stock boost and you should have no problems."

So anyhow there it is (for what it is worth).
-JR
 
#5 ·
Was it Kenneth Ying who responded to you or another sales person?
With the intake on, the boost jumped up 1.5psi on the STi with the stock programming. AFRs also jump a point. this is where the majority of the hp gains are.
He is also telling you that you should have no problems is you leave it stock. Hence he is using his litle loophole. Notice how he beats around the bush about the issues.
CARB only tests emissions BTW, not reliability, performance, etc...
If it passes smog test (albeit it's a thorough smog test), which it will because its leaner than normal, it will pass carb testing.
Quote him on specifics.
Could you tell me the before and after AFRs from your dyno testing?
How about the peak boost levels?
Something like this should result of course with some variability:
 
#6 ·
This is untuned just with a CAI.
Note the the 1psi peak boost increase of course with no additional fuel this will lean out the fuel mixture.
Also if he was familiar with the ECU cell programming he would know that boost targets given rpm and throttle loads would no longer match.
Specifically: The program says that @ 2500 rpm @ full throttle you will be at 5psi providing enough fuel for the OEM AFR goals but with the CAI opening up the intake tract, you get 12- 13psi of boost at this rpm with no additional fuel. Leaning out the curve.
I am not saying its unsafe. It still is, but all he is doing is giving you a feel better approach with no specific data. Basically "it's safe to run, and that's all you need to know" I dislike people like that when you were asking for specific information.
 
#7 ·
Joji Luz was the responding rep from AEM. I was hoping for some hard documentation\facts but alas what you see
is what I got. So I will remain on fence for a bit longer.
 
#8 ·
I'm bothered that Subaru spent a bunch of money researching intakes that they stood to make a huge bag of money on, and in the end decided not to make one. That plus I've heard the stock intake is good to 400hp is making me think I'll never get one.
 
#10 ·
My tuner told me it only hold well to about 300-325hp. After that you're defintely going to need a CAI!
 
#12 ·
For anyone running the AEM intake, I highly recommend you get a tune to adjust for the leaning out. As others have pointed out, SPT decided to not release a CAI for a reason, and since they shared development with AEM I think we now understand what that reason was. SPT has not ever released a ECU tune package before, I doubt they wanted to start.

So, if you have the AEM, do yourself a favor and pickup the OpenPort 2.0 cable, buy an appropriate map and protect you car. It's an additional $200 sure, but you will see a greater benefit from mapping then the intake anyway, and you at least know you won't be running lean.
 
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