Fly or Why? Cold Air Intakes
By Rick Reimundez
In our JET-HOT coatings coverage, frequent reader Fong brought up a great question: generally speaking, how much do we trust aftermarket parts manufacturer’s claims? One claim that I always take with a large hunk of sodium chloride is the idea that cold air intakes make power.
I think in theory, the science bears the claims out: cooler, denser air equates to more power. But frankly, I think that in practice, the results are really only relevant on the track where the difference between winning and losing is measured in fractions of a second.
I had a cold air intake on my Trailblazer that replaced the entire air box all the way to the MAF with new larger piping and a heat shield. I ran it for about 6 months, straddling a few seasons. But I found in my experience that all it got me was more noise. Granted, the noise sounded pretty mean, but it was just that. I felt no difference. I’m not saying there wasn’t any difference; I’m just saying I couldn’t feel it.
So I started thinking. Is it worth it to me to spend $300 or more on something that I’m not going to feel?
I could understand if you’re on the track – where you may not feel the results, but you’ll see them on your times. But on the street?
What do you think? Tell us in the comments.
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September 28th, 2007 at 3:40 pm
They don’t make much of a difference down in the low end, but up in the higher rpm’s they make a big difference. Here are a couple of pictures of data logs I took on my 2000 v8 Mountaineer, the only difference is a Mac cold air intake
what your looking for is the blue line, each block is an equal length of time.
stock
http://smg.photobucket.com/albums/v601/techieman33/?action=view¤t=test8.jpg
with CAI
http://smg.photobucket.com/albums/v601/techieman33/?action=view¤t=test6.jpg
September 28th, 2007 at 6:38 pm
I’ve often wondered this myself. Any comments on how they effect fuel mileage? I have used replacement K&N filters in the past, but never sprung for the “cold air” kits. Never really noticed any change in pep, just a sucker for marketing I guess.
September 28th, 2007 at 11:03 pm
There is the cost savings over replacing the paper air filter every oil change too . . .
September 30th, 2007 at 12:33 pm
Techieman has the right idea. Most aftermarket or bolt-on mods don’t make changes so drastic that you can feel them. (I mean really, can you actually feel a ~5 hp increase on a 200 hp+ engine?) To really know if a modification is worthwhile you have to dyno it.
Also, many times folks will just bolt on an accessory thinking that they are gaining performance, particularly things like freer-flowing intakes. My eperience is with motorcycles, not cars, but the principle is the same. It doesn’t do much good to tack on a K&N intake if you have restrictive headers or poor flow throught the head. If the restriction is not the intake, opening it up isn’t going to do much for you.
–TMIB
October 1st, 2007 at 10:09 am
The only one that I have seen that actually looks like it will do anything besides sound is the Pro Cold, it doesn’t have a box so it takes the air from outside instead of the fender. I think the website is pro-dyno.com or something like that.
Also, I agree with TMIB, getting all that air in won’t do a whole lot unless you can get it all out as well. Instead of starting with a $300 intake I would start with an exhaust, besides the sound will be a lot better.
October 1st, 2007 at 11:06 am
My only mod is a K&N Filter Charger II kit on my Tacoma. Though Techiman’s test was a lot more detailed, I did spend some time with a Gtech before and after. I noticed that before the kit, the gtech showed me about a 10% loss between the rated engine hp and what I got at the wheel. Using this as an assumed constant loss %, I then Gtech’d after the kit was installed showed the rated engine increase of about the claimed 10 hp.
Bottom line. I could chirp the tire in first but overall times (0-60 and 1/4 mile) were neglible. As TMIB said, I couldn’t feel it but I liked the sound better than an exhaust only because it didn’t scream unless I floored it.
October 1st, 2007 at 12:17 pm
I don’t think that the cold air has anything to do with it, it’s about getting more air. I data logged air intake temps, and once your moving more than about 25mph the temp was just a few degrees above ambient no matter what intake I was running.
I do agree that it’s only as good as the smallest hole though. It just comes down to how much money your willing to spend. There is always a bigger MAF sensor, bigger throttle body, headers, high flow cats, bigger exhaust. And then you could start porting the intake and heads, the sky is the limit.
October 1st, 2007 at 6:47 pm
Fong, was your gas mileage affected? I also have a Tacoma, and am looking to increase fuel mileage.
October 2nd, 2007 at 1:19 pm
I’m a little late getting into this one, but I’ll share my thoughts anyway…
I’ve never used the full-on $200-$300 kits like this one (e.g. the K&N FIPK), but I have installed the K&N replacement filter element on several of my vehicles. As many have stated, there is no noticeable difference in power, but the “whoosh” sound you get from the intake when you get on the gas is pretty awesome.
They’re not for every car though… For example, my 2003 Subaru WRX does not play well with aftermarket intakes unless you have your ECU modified for it. I don’t know if that’s true for all forced-induction cars or not… I remember reading something about how the turbo (or wastegate) is limited by the ECU as to how much air is going to be put into the engine, so adding a higher-flow filter/intake to a forced-induction motor really won’t do any good without the proper ECU programming to take advantage of the (potential) higher volume of air. If I’m wrong, please correct me… I’m far from an expert on the topic.