To CAI or Not to CAI, Everyone's Question

[Alaska_Wolf]

So can someone explain how a particular filter can be less restrictive to allow more air flow to "increase performance" while at the same time preventing the bad stuff from getting through the filter and into the engine? Are these filters so scientifically engineered that the filter pores can do that?

Actually, the video did a pretty good job of explaining that, put simply they don't. It also does a pretty good job of debunking many of the myths of protecting your engine while improving performance surrounding CAIs.

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[MJ12]

Honestly, I wouldn't mind installing one for the induction sound. Waiting to hear back from people who go aftermarket CAI to see if there is any noticeable difference. I have the 2.7L. I like the sound of turbos, sue me.

If the turbos are boosting, you can hear my 2.7 bronco hissing down the block with the Injen. Increased induction sound like crazy. About 2 mpg bump too.

 

[MidnightRanger]

CAI works the best when sitting in traffic jam in the summer.
If CAI had any benefits for an average mas-produced engine, OE would have long been using it instead of creating elaborate intakes to mitigate NVH.

It's easier to fool people than to convince them that they have been fooled

Cheers...

 

[Alaska_Wolf]

If CAI had any benefits for an average mas-produced engine, OE would have long been using it

Your OEM air intake from Ford is considered a cold air intake (CAI), as it is factory engineered to draw cooler air from outside the engine compartment to improve engine performance. Ford has put a lot of research into them which is why aftermarket ones are all smoke and mirrors. Thus you are correct as auto manufacturers have been using them for quite some time now, so obviously they work. Only actually valid reason to change out a CAI anymore is if you want to switch to a different filter that provides a higher filtration level than the stock Motorcraft does @99.81%. Only two filters I found that beat the stock Motorcraft are the S&B @99.88% and Donaldson's @99.99%.

 

[Lion77]

The other risk is your trusting that the mfg of the CAI has done their flow calculations right. They are notorious for not doing so, causing the engine to lean out hence why they make a little bit more power. That can actually induce knock that can over time cause hammering of the pistons and lead to a cracked land.

On older NA engines from the 1990s that didnt make much power you could probably get away with it and still expect a full service life. Im far more reserved on modern TDI engines, the power levels are much higher and mistakes have outsized impact. Im not saying there aren't CAIs that wont cause issues, what im saying is you wont know until it does and all for what? A few measly HP you can barely measure on a dyno?

Factory intakes are CAIs now. Even my lowly Mazda 3 has a CAI. Only way to improve it would be to use a larger filter thats less restrictive but on a NA 4 cylinder...thats not even worth 10 hp. Jist not really worth it in my opinion unless your doing a built bottom end with custom tuning. In that case, a larger higher flow intake your doing a custom cal for maybe makes sense.

Personally, I think for most street legal cars, including performance oriented ones like Mustangs, Corvette, Raptors, TRXs etc., your far better of focusing on rigorous maintenance so you can keep making the rated HP over the life of the vehicle.

Fords are the only vehicles I tune and I wouldn't use anything but Ford Performance on stock bottom ends because the tuning is done the Ford, its their own performance division.

 

[MidnightRanger]

Your OEM air intake from Ford is considered a cold air intake (CAI), as it is factory engineered to draw cooler air from outside the engine compartment to improve engine performance. Ford has put a lot of research into them which is why aftermarket ones are all smoke and mirrors. Thus you are correct as auto manufacturers have been using them for quite some time now, so obviously they work. Only actually valid reason to change out a CAI anymore is if you want to switch to a different filter that provides a higher filtration level than the stock Motorcraft does @99.81%. Only two filters I found that beat the stock Motorcraft are the S&B @99.88% and Donaldson's @99.99%.

Every modern engine air intake is designed to draw air from outside. Unlike aftermarket CAI, OEM are designed in a laboratory where itis tuned to produce maximum efficiency and minimum NVH.
Calling OEM air intake a CAI is just semantics.
Aftermarket CAI is nothing more than a farkle.

Cheers...

P.S. Donaldson - is the cat's meow of air filters!

 

[Alaska_Wolf]

P.S. Donaldson - is the cat's meow of air filters!

Yeah, wish we could use them. But so far the only company that builds a CAI they'll fit is Volant. Been running Volant's with the Donaldson's on my F series trucks for many years, but last I spoke with them they had no plans to address the Rangers. S&B might be worth a look as they use the Ford CAI plumbing and just replace the air box; but their dry filters are running 99.88% filtration. They even provide their ISO 5011 technical worksheet to back it up.

 

[MidnightRanger]

My 2004 Touareg V8 is currently running dual AEM dry filters(similar to Volante 5143D)
. After 20 years OE air boxes have reached the end and no longer sealed intake. Last time I'd ran OE air boxes during a very dusty trek, I ended up with a layer of fine dust inside air intake pipes leading to TB. I've been running modified air intakes for 2 years now. Yes, the MPG sucks, as so called CAI leans out AFR which forces ECU to add more fuel. At least AEM filters keep the insides of air intake dust free.
I've read about S&B, but I am still on the fence.
I want full snorkel instead of just filter replacement.

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