The flow of air into our engines in stock trim

[Lumberg]

I have noticed on close inspection that the hoses that carry air to the intake on my car (Gen 4 V6) have sort of chambers built into them. Like if the hose is a hallway, there is at least one "room" on the way to the intake.

I know that there are shapes that can create a type of resonance or affect airflow in a positive way that aren't necessarily a plain tube. I wonder if this is an example of that. The other thing I wonder is if the chambers are sort of short-term storage for when you punch the gas. The end of the tube where it sucks in atmoshpere is pretty small. Maybe the chambers are a kind of reserve for when you punch the gas.

These things make me leery of putting a CAI on my car. I mean it was designed with those chambers for a reason.

Opinions?

[CrawlingEye]

I think the one chamber is a resonator which is designed to keep down noise, if you have an 5SFE.

I'm not positive though, I'm trying to figure it out, 'cause if that's the case, there might be some extra power in taking it off and capping the end.

[smitty__16]

I think those chambers are to deadn' the sound of the intake sucking air.

[ripley's99]

the "chambers" are just big resonators to keep the engine quiet...just about every car has them. you can take them off and plug up the holes to save a tiny bit of weight and make your air flow a bit less restrictive like everyone else said.

later,
Keri

[CrawlingEye]

Originally posted by ripley's99
the "chambers" are just big resonators to keep the engine quiet...just about every car has them. you can take them off and plug up the holes to save a tiny bit of weight and make your air flow a bit less restrictive like everyone else said.

later,
Keri

Thanks, Keri. Now the next question, do you know the diameter of the opening in the air-box, or anywhere I could find the info?

I don't want to buy 5 fittings just to see which fits.

[ripley's99]

Now the next question, do you know the diameter of the opening in the air-box, or anywhere I could find the info?
I don't want to buy 5 fittings just to see which fits.

i'm not sure myself...i haven't had the time to see exactly what the size is or take my resonator off yet...on my fiance's integra, the opening left by one of his resonators (there were 2 on his stock airbox) was the exact diameter of a mobil 1 oil cap so he put that in to plug it up & its a perfect fit - the boro way but hey it works

i am guessing maybe the diameter might be similar to that size but am not 100% on that...i might have time to check it out tonite and will let you know.

Keri

[Lumberg]

That one chamber that is in front of the drivers front wheelwell is also a resonator, or more of a drip tank for water?

[88 LE]

^ Resonator.

[Lumberg]

Thanks for the enlightenment guys.

So installing a CAI will:

1) Allow more, colder air into the engine at larger throttle openings

2) Make the engine somewhat louder...because of all the air rushing into the engine in a straighter line

Is that all?

Will it affect MPG, life of the engine, cause certain sensors to detect odd conditions, allow too much humidity into the engine, or anything like that?

(Of course if you dog the engine or race that's bad but I'm saying all things being equal)

Thanks, I am very curious about this.

JC

[CrawlingEye]

I just took the res off and capped it, I haven't driven it yet, so I'll post back after I drive it a bit tonight.

Edit: Oh yeah, I used a 2" cap for it, for anyone who's wondering. It had to be tightened a bit, but it fit pretty well.

[ripley's99]

thanks for the info on the 2" cap crawling eye...i haven't had any time to try to take mine off yet

lumberg, you've got the right idea...you'll get a slight hp increase as well with the colder air flowing to the engine in a more direct path.

as far as mpg, i believe you will get a slight increase there (correct me if i am wrong anyone)
your sensors will all be fine, there will not be any excess humidity in the engine.

the only things to be careful of with a CAI are driving thru high water/splashing a big puddle...you don't want the filter to suck up a ton of water and hydrolock the engine...so you can put a bypass valve to prevent this from happening.

the only other issue i can think of is a little more dirt being sucked into the engine...but i don't think you will be getting enough to kill the engine or anything...heck when i took my stock airbox off the other day to check my K&N filter there was a cigarette butt in there
so a stock airbox gets its fair share of dirt too.

good luck & hope this helps,
Keri

[CrawlingEye]

Not much of a sound difference so far (just drove some local roads, no highways yet) but I did notice that from a stop, there's less hesitation.

I'd like to drive it on the high-way to know for certain (to rule out placebo). So far though, I like the improvement.

[Lumberg]

I am surprised that you have less hesitation off the line. I know that in general decreasing air restriction to the engine tends to increase peak horsepower at the expense of low-end torque. Maybe the improvement in throttle response is greater than the decrease in low-end torque?

I would love to see a study where someone has a set-up where it's relatively easy to switch back and forth between the stock set-up and CAI, and go to a dragstrip and measure ETs, top speeds, and especially 60-foot times.

[Wibbit]

someone correct me if im wrong, but i always thought decreasing restriction on the intake would be beneficial to power and torque as long as the pressure drop isnt too great...as there cant be too much airflow because your engine will only suck in an amount dictated by the capacity...unlike when the exhaust diametre is too big, the airflow speed slows down and our NA engine can lose torque easily. but i dont think this is the case with the intake....

when i installed my K&N CAI, acceleration was marginally better but performance depends a lot on underbonnet and ambient temperatures... which kinda sucks imo cos we dont have vents at all either in or out. might even go back to a panel

[Wibbit]

by vents... i meant bonnet vents.... thats why i need a VIS hood!