What is an intake for? (I know what the purpose is) But what I need help understanding is the use with the aftermarket intakes. If the motor is sucking in that much more air than what the engineers have designed, how is all that air leaving the vehicle, if you leave the exhaust stock? Or, does it not matter?

 

on the average car, you only get MAYBE 1 horsepower from an intake, and this only occurs at high rpms where more air is needed

 

If that's the case why bother getting one? A few years back when I had my 99 SI
I put an Injen intake on it. When VTEC hit, that car screamed. Then one day, my dad asked what the hell that noise was. I told him about the intake and his reply was ..."if the car is sucking in THAT MUCH more air, did you do anything to the exhaust to help it exit faster..." So, I have asked a few service guys at the dealer ship, but never could get a correct answer or theory on it.


[Modified by Jayhawker, 2:44 AM 1/3/2003]

 

open intake noise is louder than stock airflow because of the resonator box. i think intakes are almost a thing of the past with real tuners. i like the flat black cold air idea, or the comptech icebox intake. Sure, there is a measured hp difference, and every hp counts, but theyre made more for looks now, i think.

 

Tell that to the new RSX that made like 20hp with an intake.

 

It is from my understanding that the engineers that designed the stock box had to meet certain critera for noise suppression. So the design was to sacrafice some power to reduce noise. Aftermarket intake sacrifices the noise for to gain more power.

You are correct about the exhaust, Get a freer flowing exhaust and you will gain even more power with the intake exhaust combination. Add a header and you gain even more power.

Than you will ask yourself, With all this extra air going in and out. What about the fuel? Thats where fuel pressure regulators, injectors, ecus come in to add more fuel to gain more power.

 

about the rsx thing... i know. the K20 is starved for air from the factory, and i thought about this in my post, which is why i said "average"

 

intake just makes noise, all its good for =\

 

BS. It entirely depends upon the application, and that's the only generality you can derive here. Intake systems and filters are designed with several things in mind, only one of which is performance. And you have to realize that considering most cars aren't driven at WOT and high RPM most of the time (even VTEC Honda motors), engineers are looking to maximize intake velocities for mediocre to moderate flow. If however you are trying to set the car up for maximum top end power under WOT (which is where you spend the vast majority of your time, RPM wise, during serious acceleration), there are mild to moderate gains to be made here. Point being: if you think an intake only makes noise, drive a car that actually needs one. Like a Prelude VTEC, RSX Type S, or myriad other cars that are a good bit restricted on the top end by the stock air intake assembly.

EDIT: To answer the original question, it's a lot harder to get air into the engine than to get it back out again. The intake system as a whole (air filter, piping, intake manifold and cylinder head) represents the greatest challenge to engineers looking for maximum possible performance. Air is drawn in through vacuum and (largely) pumped out through higher than atmospheric pressure, and to put it plainly it's a lot easier to pump something out than to draw something in. So the slight additional airflow possibly afforded by an aftermarket air intake is not really a concern when talking about exhaust flow, as the difference isn't big enough to impact exhaust flow performance (only intake flow performance, as witnessed by dyno runs).


[Modified by texan, 2:10 AM 1/3/2003]