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I'm looking to get a cold air intake, either afe or TRD CAI. I just don't want to have any problems with codes trippin with the afe intake so should I get the TRD CAI instead? And have the dealership install it?
 

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I went with the TRD CAI and love it. No code problems.
 

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I can only think of three reasons for getting a CEL after installing an intake.

1) Air leak after the MAF due to installation error.
2) EVAP valve error due to incorrect installation of valve connector (presumes it was disconnected during install).
3) Offbrand intake with wrong pipe ID at the MAF or MAF poorly located within the pipe.

The first two are thanks to the installer, the third to buying a poor quality intake.
 

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I have the TRD CAI. No codes going on 32K. If I could do it all over again I would have gotten a Fujita CAI. TRD is over priced! plus dealer screws u with install fees. Check around ur area for a shop that will put it on or DIY, Gives you a sense of pride that you did it your self.
 

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What are the hp gains in these? 2-3hp?
 

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They are both excellent systems and neither would be a "mistake." They are different, as the TRD one has a "unique" filter design at the end (as opposed to the various cone filters).
I have the TRD one and am very happy with it. It is designed to be both a cold air and ram-air one, while also vapor-lock resistant. The vent theoretically pressurizes the fender at speed (not shown on a dyno).
The "cup" of the TRD system is to make the filter higher than the vent, so significant water won't get to the filter.

I'd add that the TRD stuff tends to be bit "safe" and is designed w/ a wider safety margin than most aftermarket stuff, so that owners won't screw up their vehicles with "factory" parts. That isn't unique to Toyota, as Mazda's Mazdaspeed Miata actually talked to a friend/associate of mine when picking their supercharger for it. His design is/was great, but ended up as "to much" for Mazda's final choice. Instead, they chose a less powerful system for various reasons.

As for power gains, it will be some, but more in conjuction with a higher flow exhaust- they compliment each other well. Together, I'd look for 5-ish HP.
HP gains aren't exactly additive, but it is cumulative. Meaning? Four "5 HP" add-ons/performance parts won't give you 20 HP. But, they can significantly expand powerband curve to both torque and HP for more effective power working together.
If I recall a review comparing the 2, the AFE has more top-end, while the TRD is just slightly less top-end, but much more mid-range torque added than the AFE.
In other words, the TRD has a bigger bend change in the overall power curve, while the AFE gives better max HP.
Mid-range is what I wanted, so that got me the TRD one. The manufacturer "safety margin" w/ a very comparable/competitive performance result, the extra cost of the TRD was worth it to me. Of course, I PLAN for my xB to go for at LEAST 300,000-400,000 miles and 10-15 years and 2 of my kids learning to drive on it.
 

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I am reviving this old topic since I saw your last comments, TartanJack. This is good CAI info. It would be fantastic to know the characteristics that different CAIs have like the TRD giving more mid-range torque than others. Anyone out there have any references for this kind of info?

I also wonder about the ram air effect
The vent theoretically pressurizes the fender at speed (not shown on a dyno).
I know that with the Bernoulli Principle, a high velocity fluid causes an area of low pressure. A wing shape gives lift because the air is moving around the wing faster on the top due to the curve (the air has to travel farther) than the bottom so the top has higher velocity fluid and lower pressure.

Now on an intake it's a little tougher to conceptualize. With the bumper inlet, I don't think it pressurizes the air inside the fender and the engine compartment any more. There would be an area of low pressure just outside the fender also relative to inside pressure as it is a high velocity fluid going around the car. How that affects the pressure inside and the intake, I don't know. It does bring cooler air though, which is more dense.

Any other engineers have an idea here? BrickPig?
 

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With the bumper inlet, I don't think it pressurizes the air inside the fender and the engine compartment any more. There would be an area of low pressure just outside the fender also relative to inside pressure as it is a high velocity fluid going around the car.... It does bring cooler air though, which is more dense.

Any other engineers have an idea here? BrickPig?
I considered this when I did my homebrew CAI. I don't have any measurements to back this up, however I feel that any pressure generated by the bumper inlet will be lost to the engine compartment. (Keep in mind the engine compartment is also vented to the underside of the car.) I put a plastic baffle between the intake area and the engine compartment, but that will not allow the inlet to pressurize much.

My main reason for making the bumper inlet functional was to provide a source of cooler (and therefore more dense) air to the engine intake. I did this mod after only 3 days of ownership so I don't have any before/after comparison. However when you look at a variety of OEM snorkels and their efforts to get cooler air, there must be a benefit, else the OEMs wouldn't do it.

The only question remaining for me is, why didn't Scion route the factory snorkel to get cool air, like maybe from the front grill? The stock snorkel is certainly long enough. There must be some other reason they did not, like maybe very cold weather performance, or perhaps to mask intake noise (neither of which I was concerned about). I postioned my intake hose in the upper half of the bumper vent, so only a VERY deep water puddle would put me in trouble.
 

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Yeah, it's not like the engine compartment is air tight to any degree. I'm thinking now like a computer case, we need lots of fans blowing inward to get positive pressure inside, lol. Ok, so pressure is a tough one, probably no effect, and nobody I know could measure it anyway.

I just saw your CAI on your page again and when splashing through some deep puddles today I think I would put it a little further back myself. Actually I'd put some black plastic screening right behind the inlet which would get all the big drops. But this is a splash I'm talking about, not actual deep water so might be ok anyway. Though I have been whole-car splashed across a barricade from a truck in opposing traffic on an interstate before. I guess as long as the water that gets further in is only small mist or something then it's fine.

I also would have liked them to put in a stock CAI. I mentioned my friend's Audi S5 has it. The 2012 Camry I had as a loaner also had one. And now my wife's new 2013 MINI has a very nice stock CAI (I can even hear it in acceleration). I agree about the benefit and doubt the naysayers because of this also.
 
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