Quatre Coureur
New member
^Don't worry there's one born every minute! :jaw drop:
Why your "cold air intake" is mostly a waste of money
- Thread starter KidVermicious
- Start date
WillK
New member
So, I'm running an Injen intake with the new dry Amsoil filter and a Borla XR-1 muffler. I got back the gas mileage I lost when I went from 265 tires to 285/75/16. I have a 20 mile drive to work in mixed city and higway and I average 21-22 MPG. And I don't drive slow - typically 5-10 mph over the speed limit.
So, why am I doing better with the Injen than the Stock AirBox and the ISR mod. I'm also getting better mileage with E weight 285s that the Stock Air Box and 265 tires.
Also, amoung the scaguageII owners there is not much difference between CAIs and the stock airbox..
http://www.toyota-4runner.org/3rd-gen-t4rs/108171-scangauge-ii-owners-intake-air-temps.html
op2:
You're wasting your breath. This is the only board I've ever been on that doesn't believe in intakes, cold or not...
I wonder what the members at pt.net or ls1tech think of the so-called study.
And any study that measures frequency for air flow is uselss...
ALBPM
New member
KidVermicious
New member
So demonstrate why it's useless, and then bring something that isn't.
The internet is full of guys who bought the snakeoil and want to believe that their "cold" air intake/throttle body spacer/high flow cat/fuel magnet/whatever is making their truck faster, and will tell you all about how they get better mileage or can feel the extra power, and that's all worth exactly two small buckets of half-priced crap. Anecdotes do not equal data and prove nothing.
There's two cites in this thread alone with real data in them. If you wanna bring an independent study supporting your own conclusions, I'll be happy to read it.
eddiebx
New member
However, I read somewhere that CAIs help increase acceleration because of the weight reduction...in your wallet.
:noidea:
mikebontoft
New member
simply put, yes the K&N and similar filters are better. why? well yeah, they don't filter worth shit. It's just as effective as sticking a pair of pantyhose over your intake in place of the filter. You'll end up dusting your engine if you own the car long enough.
The foam ones do flow close to about the same, but they still require oil to capture particles.
I see quite a few cars in the shop with K&N filters on them. Don't think I've ever seen a single one properly cleaned and oiled. I don't think they ever had oil on them!
That's the other thing... people either don't oil them at all, or over oil them. if you over oil and you have a MAF sensor, guess what? it cooks onto the sensor.
In all honesty though, I have a cheapo one on my truck that I've also never oiled. it's clean, but it's not oiled. Why should I care though? the engine I got cost me $100 and already had K&N crap on it. "It's too late. The damage has been done."
The foam ones do flow close to about the same, but they still require oil to capture particles.
I see quite a few cars in the shop with K&N filters on them. Don't think I've ever seen a single one properly cleaned and oiled. I don't think they ever had oil on them!
That's the other thing... people either don't oil them at all, or over oil them. if you over oil and you have a MAF sensor, guess what? it cooks onto the sensor.
In all honesty though, I have a cheapo one on my truck that I've also never oiled. it's clean, but it's not oiled. Why should I care though? the engine I got cost me $100 and already had K&N crap on it. "It's too late. The damage has been done."
EatonKyleH
New member
I'd buy a CAI or K&N filter if it had cold activation like a Coors can and turned blue when it was as cold as the Rockies.
Until then I'll pass and keep my MAF oil-free.
Until then I'll pass and keep my MAF oil-free.
Last edited:
KidVermicious
New member
But even if they could theoretically flow more air (which may be true and I won't argue) it doesn't do any good if the motor isn't actually requesting that air.
I'm playing games with my little 22RE. It's got a 261 cam that slightly changes the valve timing, it's a got a Thorley header that does a little better job of letting the cylinders evacuate exhaust than the stock manifold. I'm going to be replacing the stock cylinder head with an RV head with oversized valves - that and the exhaust header WILL help the motor request a little more air at the intake, and to compensate for that I'm going to convert my intake tube to something uber smooth and probably stainless, and I'm going to open up the AFM and throttle body just a touch. I may upgrade my spark or see about injectors that flow a little more. But I'm gonna leave the stock filter in the stock box and in the stock location, because there's no way in hell my little tiny modifications are going to induce my motor to try and pull more air than the stock filter can flow.
It's the same with the guys in this thread claiming performance increases. Until I see dyno results where the ONLY variable is their air filter, I'm not gonna believe for a second that their spiffy Injen or K&N did anything except lighten their wallet and make their motor a little louder.
TRDCal
New member
I believe the theory is not that a high flow filter pulls more air in, but that it requires less energy to pull the same amount of air as a stock filter. It's a 2 way street, if a dirty filter restricts performance, then a clean filter will improve performance. So if a K&N (or whatever brand) is less restrictive then a stock filter, why wouldn't it produce a similar (obviously not to the same magnitude but you get what I mean) result?
I don't really want to get into this argument, that's just my understanding of the theory behind intakes. I bought a Volant CAI 2 years ago, it was on my truck for 6 six months and has sat on my shelf for the past year and a half. Why? I don't like the "throaty vacuum" sound. But that's just me, I don't (nor do I understand why others) care if someone else half way across the country wants to put one on their truck.
To each his own...so why can't we just agree to disagree and save our energy for another argument. :hippie: :canada: :thumb3:
See...that's the thing...its about the wording or what's being advertised by these air filter and CAI manufacturers.
I do believe that aftermarket units do allow the engine 'to breath' easier mostly under high load/rpm...by allowing the engine to do slightly less work to bring in air, it does free up some HP...Significant? In the grand scheme of things, NO.
Now thing whole thing of improving gas mileage...hard to believe...think about it...
In modern computer controlled engine, the PCM is going to do everything it can to kept the ideal ratio (stoichiometric (sp??) mixture) of 14.7:1 or close to it. So, based on the amount of air, it will adjust fuel metering accordingly. More air (O2), more fuel, less air, less fuel.
Given this, it seem that aftermarket system will do the opposite...if more air is indeed coming in, the PCM will add more fuel to keep the ratio...more fuel used, worse gas mileage.
And remember, fuel mileage is one of the most difficult things to measure accurately because there are so many parameters affecting it...even the EPA can't get it right or create a standard...hence the latest Ford hybrid fiasco...
Anyway, its your money and your truck...do with it as you will...its a free country...so far...
I do believe that aftermarket units do allow the engine 'to breath' easier mostly under high load/rpm...by allowing the engine to do slightly less work to bring in air, it does free up some HP...Significant? In the grand scheme of things, NO.
Now thing whole thing of improving gas mileage...hard to believe...think about it...
In modern computer controlled engine, the PCM is going to do everything it can to kept the ideal ratio (stoichiometric (sp??) mixture) of 14.7:1 or close to it. So, based on the amount of air, it will adjust fuel metering accordingly. More air (O2), more fuel, less air, less fuel.
Given this, it seem that aftermarket system will do the opposite...if more air is indeed coming in, the PCM will add more fuel to keep the ratio...more fuel used, worse gas mileage.
And remember, fuel mileage is one of the most difficult things to measure accurately because there are so many parameters affecting it...even the EPA can't get it right or create a standard...hence the latest Ford hybrid fiasco...
Anyway, its your money and your truck...do with it as you will...its a free country...so far...
It's all a crock of shit. I think there are 2 different arguments going on here. The type of intake system (factory or aftermarket) and the type of filter being used (Paper/Oiled). I dont see what there is to really argue about here. Paper filters better, but is more restrictive. Oiled filters flow better, but dont filter for shit. Just like a carb'd air filter top being flipped. Yeah you get a little more mustard on your fries, but your letting unfiltered air into the engine. Its a give and take. Like someone said, its your money and your car. As far as the type of intake, I can see a miniscule power gain from the smoothing of the airflow from the lack of silencer boxes or whatever they are on factory intake tubes. But miniscule isnt worth the $$ you gotta fork out in my opinion. Want better gas mileage, run premiuim gas. I'm not a believer in these aftermarket chips either. My old truck got 3-4mpg better when I used premium. I saw an aftermarket chip for $400 that offered 3-4mpg garunteed, but you had to use premium gas. Everyone wants the miracle cure and they want it yesterday. Too each his own I reckon.
WillK
New member
First, you can't compare old carb cars (no computers) to new cars (computer controlled). It just doesn't work. In an old carb'd car you could take off the air cleaner (which many did), run open headers and not effect the car at all. Simply make small adjustments to the air/fuel screws on the carb or increase the timing with the old timing light and a twist of the distributor. Try running a new car with open headers or no intake at all and see how well it works! lol
As for intakes (I don't like to call them cold air intakes), they don't allow more air into the engine- that's physically impossible and restricted to the size of the throttle body- that determines how much air can come in.
You can put a 6" tube on an engine, but if the TB only has a 70 mm opening, that's all the air that can go in.
(Although I haven't looked at it, I would assume the 5.7L has a bigger throttle body. If it is, then that's the TB to use to get more air into the motor).
What intakes are designed to do, in theory is allow for a more efficient flow of air into the engine. And they do that by two factors- straight through tubes and bigger (usually a conical), more porous filters. Again, in theory- that's how they do it.
Does that equate to more power, possibly (in theory). But again, without actual dyno numbers, it's hard to say. But I know in other vehicles I've had a baseline dyno pull, then went back with an intake and saw a modest 6hp/13tq gain on my 286hp/335tq motor. Not bad, but certainly not the 18+hp as advertised.
But where I noticed the difference, is better throttle response and it seems to hold a gear longer without downshifting as much. An example would be merging onto the highway. A half-pedal while going down the long on-ramp and it holds the gear, instead of downshifting. I like that. Less wear on the transmission, IMO.
And combined with my Magnaflow muffler, it sure does sound nice!
As for intakes (I don't like to call them cold air intakes), they don't allow more air into the engine- that's physically impossible and restricted to the size of the throttle body- that determines how much air can come in.
You can put a 6" tube on an engine, but if the TB only has a 70 mm opening, that's all the air that can go in.
(Although I haven't looked at it, I would assume the 5.7L has a bigger throttle body. If it is, then that's the TB to use to get more air into the motor).
What intakes are designed to do, in theory is allow for a more efficient flow of air into the engine. And they do that by two factors- straight through tubes and bigger (usually a conical), more porous filters. Again, in theory- that's how they do it.
Does that equate to more power, possibly (in theory). But again, without actual dyno numbers, it's hard to say. But I know in other vehicles I've had a baseline dyno pull, then went back with an intake and saw a modest 6hp/13tq gain on my 286hp/335tq motor. Not bad, but certainly not the 18+hp as advertised.
But where I noticed the difference, is better throttle response and it seems to hold a gear longer without downshifting as much. An example would be merging onto the highway. A half-pedal while going down the long on-ramp and it holds the gear, instead of downshifting. I like that. Less wear on the transmission, IMO.
And combined with my Magnaflow muffler, it sure does sound nice!
fun_runner
New member
Or boost . . . just sayin. :beer:
MtnT4R
New member
You want air to make more power? Try forcing it in there.
I was always curious about this. How come a supercharger gives substantial performance gains, while a CAI doesnt at all?
KidVermicious
New member
It's an air compressor. Denser air.contains more oxygen, which you can balance with more fuel, and more oxygen and fuel in the cylinder means more boom.
