xd69

iTrader: (1)

when it comes to cai, the bigger the diameter(ie. itr=3inches), the more power you gain over smaller diameter(ie. prelude or 99-00 si). everyone on ht says to go with the itr intake for an h22 civic cuz the diameter is bigger and you'll get more hp. correct me if im wrong but i always thought that velocity was greater than mass, meaning it doesnt matter how much air you are sucking in, what matters is how fast the air is traveling in. if you have a 3inch diameter intake yes it will suck more air but at the same tame it wont travel as fast. if you have a smaller diamater intake it wont suck in as much air but the air will be traveling faster due to the smaller diameter. what do you guys think??

snatch

You're logic is fairly correct with the smaller diameter means higher velocity, and a bigger diameter means lower velocity but more air.

I think what it boils down to is what does your particular engine need, and how much air can your engine draw in. For cars with smaller and less demanding air needs such as D-series, they will likely benefit more from a 2.5" intake at the throttle body as opposed to a 3". A H22 though, might be better with a 3" intake.

doughboy_88

on the lines of what ****** was saying, wider diameter piping is good up to a certain point. you want to increase air flow without losing torque.

Hapexamendios EJ8

this applies to exhaust systems to doesnt it?

SOHC4life 96

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hapexamendios EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">this applies to exhaust systems to doesnt it? </TD></TR></TABLE>

In some ways it does. However, with turbo cars a smaller diameter exhaust is better because they need backpressure. While a turbo car needs to breath to make their power so a large exhaust is best.

xd69

iTrader: (1)

with that said, what intake do you guys think would best benifit an ek h22?? si,luder,itr,etc....??

duh blacksheep

for intakes, my guess would be that the bigger the intake the better. true; the smaller the diameter, the faster the airflow, but you are also counter-acting the air velocity with air flow restriction. (assuming a typical street car/setup)

mwieczorek43

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by duh blacksheep &raquo;</TD></TR><TR><TD CLASS="quote">the smaller the diameter, the faster the airflow, but you are also counter-acting the air velocity with air flow restriction. </TD></TR></TABLE>
Please elaborate.

MiMiK

iTrader: (1)

meaning, in a smaller pipe, air velocity will be higher but not as much airflow will be allowed.

duh blacksheep

thats just the way the cookie crumbles.

PupaScoopa

You'll see why air velocity is so important when you slap on your 3" intake and notice a huge loss in power right off of idle.

Kyles ej1

smaller piping is for low end bigger is for top end, thats y i got a v2, it has the best of both worlds

duh blacksheep

actually, the section where air velocity is most important is probably some place by the valves, with any restriction of the air inlet will only slow down the air speed into the cumbustion chamber.

xd69

iTrader: (1)

so do you guys think that i would notice a difference b/w the si cai and the prelude/itr cai??....im not sure what diameter size the si is, but im thinking 2.75? if it is 2.75 will .25inches make a great difference??

Archidictus

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xd69 &raquo;</TD></TR><TR><TD CLASS="quote">so do you guys think that i would notice a difference b/w the si cai and the prelude/itr cai??....im not sure what diameter size the si is, but im thinking 2.75? if it is 2.75 will .25inches make a great difference??</TD></TR></TABLE>

Nope.

With stuff like this, like anything else in this game we play, the winning combination is all about balance. You can't have your cake and eat it too unless you spend a lot of money on parts that function together as a gestalt. That said, you won't be able to have a 5 inch diameter CAI and get good low end response on a 1.6L motor. Likewise, you won't be able to have a 1 inch diameter CAI on an LS1 and get anything over 3,000 other than noise and black smoke.

2.5-2.75 is great.