Truth about Intakes

[theKnifeArtist]

so my teacher at UTI tells me that aftermarket intakes don't do anything to your car except for give you a more aggressive sound, unless you have forced induction..maybe he isn't up on the times...or is he right? i'd just like to know what it really is.

 

[inline6]

Hes probably right. A stock air filter would need to be a restriction in order for you to gain power and most probably aren't that restrictive.

Even for supras, the BPU stage does not include an air filter, so it must not be seen as much of a restriction.

 

[dbsupra90]

this isnt true. they do increase power on our car. maybe not a ton at near stock levels, but the more mods you have the higher the power gain.
i believe on a stock 7m i saw an air filter comparison on a dyno. i think the apexi had the highest gain ~11rw and the k&n filter at ~9rw. sure that isnt a lot, but this is on a stock motor.

inline6-
the hks stage upgrade the filter is the second mod. first mod is exhaust.

 

[ValgeKotkas]

^ are we talking about 7mgTe?

On older cars maybe yes, maybe the stock filters are old technique, but I guess on newer cars you just get a feeling you go faster cause you paid a lot of money and it says so on the label....
Or actually... im sometimes on the citroen c2 forum, and the most popular mod is the intake.. they usually say, you gain like MAYBE 1,5hp (on a 110hp crank), and the throttle response seems to get a little better....

 

[TobyCat]

on most cars, the cone filters don't do anything because air intake is now drawing warm are from under the hood...so sure you're able to pull in more air without restriction, but it's warm air. So the net gain is negligable. I've talked to a few of my mechanic buddies, and they say they're taught this as well.

As far as turbo'd cars go though, you're going to throw that air through an IC anyways. Sure it's better for it to be cold to begin with, but the heat soaking isn't as much of a problem.

Although I've seen dyno graphs online of people who claim 8hp from their K&N...I didn't feel anything different other than being able to hear the turbo spool and stock BOV

 

[xXxICExXx]

The intake is soooo key that people dont even understand. Yes, it gains 9-11 rwhp, not a whole lot......but what if you choose to add exhaust, turbo elbow, test pipe, bov, boost controller, IC and hardpipes, 550s, tt fuel pump, etc etc but do that the whole long way without an intake? shit if you put that intake in it would be a lot more than 10 hp. Its needed for this car, especially since its turbo, its the first step to mass air flow.

 

[mkiiSupraMan18]

Helped or not, my RabidChimp intake looks a helluva lot better than the stock black plastic crapp. :icon_bigg

I didn't notice a difference in sound... but it's kinda hard to hear over the new DT header that I put on at the same time. As far as performance enhancement, it gave me a whopping -7hp! :icon_bigg


And kind of a side topic yet related:
I was talking to Jon at MDC about some head work once upon a time and he said that a slick finish (like polished) is worse at flowing air than a rougher surface... (this was talking about the intake runners and all of that jazz, but I would assume it would hold true for all pipes)

Something about the air sticking to it when its slick and doing the "driving fast on a washboard road" skimming accross the dips on the rougher surface.

Just curious about whether or not he's full of it because I'd eventually like to get a head built up for the 82 and one of these days make some really good #'s with it.

 

[cjsupra90]

On an N/A car, the airflow meter is probably more restrictive then the filter/airbox assembley.

If you want to test your setup, instal a vacuum gauge between the airflow meter and the filter and run it in to the driver compartment, do a full throttle run to redline and see how much if any vacuum is drawn. Anything more the 1.5 in/hg then yes, it is being restrictive enough to be causing a small lose of power, but only a couple at that unless the number is significantly higher then that like 3 or 4 in/hg.

This has been a monitoing system for years in the trucking industrty. Most all Seim's have a airfilter gauge in there dash, and its just a glorified vacuum gauge that alerts the driver when the airfilter is becoming dirty and clogged. I have also read somewhere that a lot of auto manufactures were toying with the idea, and I want to say that it said the new (either) BMW's or Mercedes's have this also via a warning light.

 

[supra90turbo]

Very nice, Chris. This is true.
Even the light duty diesel trucks by ford, chevy and i think dodge too have an air filter gauge on the airbox. it'll stay at the highest vaccum point until you reset it. it's a quick gauge on how well or poorly your air filter is working. it's just got a little plunger inside that moves inward slowly with vacuum.

 

[inline6]

this isnt true. they do increase power on our car. maybe not a ton at near stock levels, but the more mods you have the higher the power gain.
i believe on a stock 7m i saw an air filter comparison on a dyno. i think the apexi had the highest gain ~11rw and the k&n filter at ~9rw. sure that isnt a lot, but this is on a stock motor.

inline6-
the hks stage upgrade the filter is the second mod. first mod is exhaust.

BPU is considered a downpipe, catback, boost controller, and FCD or BCC.
And I thought this was discussing cars in general which in most cases the stock filter is not going to be restrictive enough to cause much power gain from an air filter. And don't add modifications to the argument because of course you will need a better flowing filter if running, say a T78 or any higher hp modifications, but stock it will probly not add much at all.

I saw the comparison you are talking about and I'm not sure I buy that much of a horsepower difference from just a filter. Maybe if the cars were well modified and the filter was a huge restriction but at stock levels I dont see 11rwhp from a filter.

I'm not saying not to run one, just saying the teacher is probably right for most stock cars.

 

[s383mmber1]

So your tellign me that jsut about every car thats modified with an intake have not gained anything?

I think not,

Ill stick with the intake, it sounds cool.

 

[bigaaron]

With elevated boost levels the stock airbox does become a restriction. It takes more vacuum to suck air through a stock filter box then a big open element filter, and that translates to less boost. Why do you think big hp cars sometimes run no filter at all?

 

[s383mmber1]

With elevated boost levels the stock airbox does become a restriction. It takes more vacuum to suck air through a stock filter box then a big open element filter, and that translates to less boost. Why do you think big hp cars sometimes run no filter at all?

exactly.

 

[JustAnotherVictim]

For me I noticed a faster spool when I changed to a cone filter.

 

[inline6]

So your tellign me that jsut about every car thats modified with an intake have not gained anything?

I think not,

Ill stick with the intake, it sounds cool.

You have no reading comprehension. I said a stock car (not even supra specific) will have minimal gains with just the addition of a filter. It would need to be a restriction of the system to make any real gains and for most cars they are not extremely restrictive at stock levels.

It could be compared to running a 3.5" exhaust. This would yeild gains over stock yes. But would going to a 4.5" exhaust yeild any gains over that? Not much until 3.5" becomes a restriction again (i.e. high HP). Get it?

 

[1989MKIII]

i donno on this one, i noticed a huge gain when i put on my intake on my MK3, but i also did hard pipeing all the way around. also, my truck, (80 GMC shortbed, with a simi built vett 350) there was a huge differnve when i rain a intake hose to the frount grill. but this is just IMO

 

[Sl1dewaysSupra]

For around a hundred bucks you might as well, if not for power at least to clean up the engine bay.

 

[inline6]

For around a hundred bucks you might as well, if not for power at least to clean up the engine bay.

I completely agree with that.

I was just trying to show where this teacher is probably coming from, and he is definitly not talking Supra specific.

 

[Insidious Surmiser]

on most cars, the cone filters don't do anything because air intake is now drawing warm are from under the hood...so sure you're able to pull in more air without restriction, but it's warm air. So the net gain is negligable. I've talked to a few of my mechanic buddies, and they say they're taught this as well.

As far as turbo'd cars go though, you're going to throw that air through an IC anyways. Sure it's better for it to be cold to begin with, but the heat soaking isn't as much of a problem.

Although I've seen dyno graphs online of people who claim 8hp from their K&N...I didn't feel anything different other than being able to hear the turbo spool and stock BOV

exactly what i was thinking... so drop in k&n filter IMO is the best idea for near stock motor... leter i'll throw on a huge cone and fab a box for it... you know, to shield it from the hot air

 

[boostadikt]

stock air filters are designed to be restrictive! why? because of sound that is why you get the aggressive sound when you add an intake, toyotas and honda's are most notorious for this go for a ride in a new camry and tell me if you hear a sucking noise... so the intake itself is not adding hp you will get the same gain from removing the intake box as you will by putting on a aftermarket filter, there are also other factors like a fram drop in filter compared to a k&n drop in the k&n will breath a little better and give you maybe 1-2 hp but no biggie....... seriously go look at a stock air box the air only has a 4 inch hole to get in compared to an open filter. done and finished.

also my buddy just started at uti like 1-2 weeks ago so if thats when you started and you meet a kid named travis tell him steve says to suck his left nut. peace

edit: k so just clear up a little bit, restriction again if you take a stock civic with a moderatly dirty filter and put a k&n filter on it you will maybe see 5-6 hp, but i mean thats like 4% gain on top of the bigillion hp they come with. also tho aftermarket intakes do improve gas milage 1-2mpg because of the restriction and this has been proven over.