To CAI or Not to CAI, Everyone's Question

[Alaska_Wolf]

Been reading a lot of the discussions on here about CAIs. There's been a lot of how this brand is better than that brand, and how manufacturer A says theirs is so much better than brands B, C, X, Y and Z. And how this manufacturer submitted a Dyno that categorically "proves beyond a show of a doubt", yada yada yada, blah blah blah; a lot of marketing hype, but no actual science based fact. For many years (decades) I've run Ford F - series vehicles and I've always done what made sense to me, and what I learned going through auto shop classes, and its worked. When my old 95 EB 351 Bronco (REAL Bronco) hit 180K miles, I let my friend Ralph (Ford Master mechanic, GM Mr Goodwrench Master mechanic, Toyota Master mechanic, & and NASCAR Master mechanic) tear into it, mostly out of a sense of curiosity as I had been maintaining it the same way for a long time, Mobil 1 and Volant CAI running Donaldson Powercore 99.99% air filters. Ralph found no visually discernible and only minor measurable wear in the 351. The oil quality, and most importantly the air filter quality were what was most important, that Volant CAI was primarily installed to hold the Donaldson Powercore. Donaldsons are as some of you know used in Kenworths, Macks, Freightliners, and heavy CAT equipment, all with 1,000,000 engines. I've already put the Volant CAI with the Powercore on our new F 150 Powerboost.

Anyway, the true strength behing any CAI is NOT the CAI, but the quality of the filter inside the CAI. I found a video by Jamon at Freedom Worx that addresses the actual marketing, and more importantly, the science behind CAIs. Its sure to piss off some people, maybe, but it should also make people think about what's really important about CAIs, probably. Anyway Jamon is worth listening to, and he's also a lot of fun to listen to, mostly. The TRUTH About Cold Air Intakes

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[pablo94sc]

CAI are snake oil. There, saved everyone a click.

 

[Alaska_Wolf]

CAI are snake oil. There, saved everyone a click.

Well you should let Ford know since they install CAIs on most vehicles now, including Raptors and Shelbys.

 

[stuartmunto]

Unless you’re doing a custom tune, it’s not worth it. A CAI is a supporting mod, if you’re staying stock a CAI won’t gain you anything

 

[stuartmunto]

Well you should let Ford know since they install CAIs on most vehicles now, including Raptors and Shelbys.

Cold air intakes definitely work - much better than a hot restricted intake. But we’re not talking stock air boxes here. We’re talking aftermarket intakes. And all aftermarket intakes aren’t going to do much unless you’re tuning for that particular air intake. Luckily for us Ford’s stock airbox is already a very decent CAI

Sure, you might get 1% increase in power or even slightly better back to back 0-60 pulls potentially due to cooler intake temps. But at that point the inter cooler will matter more. Again, an aftermarket CAI is a supporting mod. If you’re not changing intercoolers, charge pipes, ECU tuning then it’s just not worth the $$$

 

[Alaska_Wolf]

Sure, you might get 1% increase in power or even slightly better back to back 0-60 pulls potentially due to cooler intake temps. But at that point the inter cooler will matter more. Again, an aftermarket CAI is a supporting mod. If you’re not changing intercoolers, charge pipes, ECU tuning then it’s just not worth the $$$

Well if you listened to it you missed the entire point of a very good article.

 

[BigBassDaddy407]

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.

 

[stuartmunto]

Well if you listened to it you missed the entire point of a very good article.

Bit hard to listen (?) to an article when the link to said article doesn’t work mate

 

[Alaska_Wolf]

Bit hard to listen (?) to an article when the link to said article doesn’t work mate

Odd, working fine for me, but I renewed the URL. It really is a good article.

 

[STEVE_K]

Now I need to eat some bacon and clean some guns after watching that video.

Some good info in there. I’ve always been too cheap to buy a CAI system, or just preferred to spend the money on something else.

 

[Onceaneagle]

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? And how does "cold air," which seems to me to be any air not yet warmed by the engine, exist in the Arizona desert heat or any State with high temps and high humidity in Summer? I see more smoke and mirrors than actual science and engineering, so that's why I am asking.

 

[Sauce]

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? And how does "cold air," which seems to me to be any air not yet warmed by the engine, exist in the Arizona desert heat or any State with high temps and high humidity in Summer? I see more smoke and mirrors than actual science and engineering, so that's why I am asking.

Im a novice with this stuff, but my laymans understanding is that it is a function of having a larger filter. More surface area to draw through makes it less restrictive even if the membrane offers the same or better filtration.

I think the real punchline though is that for an aftermarket CAI to be effective it needs to address the bottleneck in the system and most of them might offer better flow at some point, but if that point isn't the bottleneck then it isn't really doing anything.

 

[Sharpie223]

There used to be a time where a COLD air intake was a notable difference from a factory intake, not so much anymore. Though some marketed as cold air intakes these days are really short ram intakes that are pulling in warmer air than stock unless you also create a barrier from the engine heated air.

What really matters is a HIGH FLOW intake. This can be done while maintaining the same level of filtration, and piping can be made to be a velocity stack instead of sharp transitions, designed for laminar flow with less impedance than stock. Won't make much of a difference unless you have other supporting mods and even then only at large throttle angles.

That said, other forums, generally for higher (perceived) performance vehicles, have done side by side intake dyno tests. Some do make a difference even in otherwise stock vehicles. I wish we had that here, but, you know...money.

 

[Lion77]

One big caveot is the filter quality. Cloth filters and dry type filters typically have about 1/3 of the dust capacity of OE paper filters and their flow characteristics are not linear, rather exponential.

So they flow better for a short period of them, then rapidly clog up and become MORE restrictive than paper filters which have a very linear and slow clog rate. Then there's the filtration quality, I've seen some testing that showed K&N's allowing up to 12x the fine dust contamination of OE paper filters.

Upper cylinder group wear (particularly the piston rings) is directly proportional to the dust contamination! So, I have contended for some time that aftermarket CAIs are for track cars, which is a clean environment, very low miles, but not suitable for street cars and especially off-road.

So, is ~7-10 hp, if that, really worth loosing ring seal by 70~100k? How much HP are you going to lose from compression loss vs. what you gained by the CAI? I think most of us should focus a lot more on making consistent and reliable power over the life of vehicle than chasing a couple of situation specific HP you can barely notice.

Hence for Ford Performance uses conical paper filters in the GT350 and Stage 2 Power Pack I had on my 2016 Mustang GT which used the GT350 throttle body and air induction system:

Note that I fabricated a custom lexan cover and riveted it on since the original GT350 intake was designed for the GT350 hood profile and didn't' seal the best against my standard GT hood, then I did some ducting up front on that to make it a ram cold air intake.

Yes, Ford Performance does use K&N's in some of their kits, but not many and I believe they intended those for cars that mostly see drag strips and operation in clean environments.

All the factory intakes now on performance Ford vehicles are cold air or cool air from the high pressure zone right in front of the radiator. That is where the body is designed to funnel incoming cool air.

Also mounting the intake higher up instead of low down helps with cooler air when driving on hot pavement, the hottest air is actually down near the surface of the pavement, so it makes perfect sense to pull the air from up near the top of the front of the hood furthest away from heat sources!

About the only significant improvement I can forsee is maybe using a larger filter to 1. reduce restriction and 2. increase dust capacity thus making its clog rate even slower and more consistent (i.e., a large conical filter like what is used on 6.7L Power Stroke).

A better intercooler is going to be far more beneficial than a CAI. THen there's the issue of trusting the CAI developer that their flow ratios are accurate, if they are off, then you're going to lean out the air fuel ratio but the PCM won't know and you could induce damaging levels of knock that hammer the tops of the pistons and over time crack a land.

I have a Pro Cal tune, under warranty and won't even do an intercooler until warranty is up. After that, intercooler and Pro Cal only. Not messing with induction system to avoid issues down the road and I simply don't think that juice is worth the squeeze unless you have a custom tune.

 

[Jason B]

Manufactures have been putting CAI in ALL vehicles since the 90s.
But as mentioned, the real benefit of aftermarket CAI is the less restrictive filter due to a larger surface area. Personally, I'd never use a filter that requires oiling to increase filtration.

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