How it Works: Intake

[MemphisRheins]

How it Works: Cold Air Intake


This article will be the first of several basic articles explaining the more common modifications made to the TSX, my aim with this article is to improve ones understanding of the parts and their function, so that you can learn more about what is going on under your hood, and what exactly you are doing.

Air Flow:
The function of an Intake is simple, to get the needed air for combustion. I don’t want to lengthen this article with all the information on how exactly an internal combustion works, but a simple analogy is a Potato gun, Oxygen plus an explosive fuel needs to be compressed in the chamber, and when the spark hits the air/fuel mixture it causes an explosion. This explosion when contained causes the potato to launch, or the pistons to compress. Engines work off of this compression, the Pistons are connected so that when one compresses the other expands, and so on, this force is also transferred to the transmission, and so on. I know the above is a very loose description of how an engine works, but its more then enough to understand why and intake is an important part of your car.

So that being said, as automotive enthusiasts our goal with the intake is to improve it so our engines can get more air, in a easy manner. A Turbocharger or Supercharger is the best way to do this, they force feed more air into the engine at a higher rate, for those of us however with smaller wallets, or the desire to keep a car naturally aspired, an Aftermarket intake can help channel the airflow to the engine, allowing it to breath easier. Also a general rule is that: Cold air ? Horsepower, this fact can be easily seen on a cold day, your car will have more horsepower and be more responsive on a 55* day then a 90* day.

Air Intake Systems:
OEM
The OEM Intake system consists of several parts; a large plastic air filter canister, plastic duct tubing, a resonator, and several rubber pieces connecting systems and the duct work to the throttle-body. This system is actually a very good design from an economical standpoint and its placement is low and behind the fender allowing it to suck in colder air from outside, for better throttle response and horsepower.

There are of course some problems with the OEM set up, the first being that its simply not a performance oriented system, the plastic ducts and the Resonator are designed for emissions control and noise control, not for the best possible airflow. removing the resonator and channeling the airflow has shown some minor gains for the TSX.
The Piping itself is also a problem, if you look at the tubes, youll notice they have ridges, these ridges decrease the air flow by adding turbulence to the system.
The other big problem with the stock set up is the paper air filter that comes from the factory, this is designed with price in mind, not performance, replacing this filter with a K&N or a Spoon Drop in filter is a major plus, not only for the better airflow, but for the better filtering capability and reusability.

Aftermarket Air Intake
Aftermarket intakes solve this problem in two ways, first they offer a wider pipe with less bends for a better flow, secondly they replace the cheap paper filter with a higher quality filter which maximizes durability, filtering and airflow.

Now the two most common form of intakes are the Cold Air Intake and the Short Ram Intake

The Short ram is the more basic of all intake systems. It is made up of a higher flowing tube, with a cone filter attached to it. These changes make it extremely effective for the high flow of oxygen vs the bends and tunnels of the stock airbox. However like its counterpart the Cold Air, it also causes a loss in petal feel in the lower revs and loss of low end torque, it makes up for it however in the higher rpms with the added horsepower.

The problem with the short ram is while the OEM intake sucked better colder air, the short ram draws from inside the engine bay, your engine hits some pretty high temperatures, This combination of limited and warmer air causes fuel-rich combustion mixtures that don't burn as well as they could.


The advancement of this is a Cold Air Intake. The Cold Air is simply an extended form of a short ram, the cold air places the cone filter where the resonator once was, inside the front bumper, this allows the engine to suck up cold air from behind the bumper, rather then the warm air underneath the hood.

The Negatives of a cold air Intake are: Loss of Low End Torque, and a risk of hydrolock (though minor) hydrolock is not a major concern if you were to ask me, however if you have really bad luck and/ or are worried about the risk, AEM makes a bypass valve, that will fit most CAI intakes. Also the Cold Air will change the overall sound of the TSX under throttle.



SR/CAI Install thread: http://tsxclub.com/forums/showthread.php?p=150191


Lastly there are the Aftermarket Box Intakes, such as mugen, J’s racing and The Comptech Icebox… these box shaped intakes are quite similar to the OEM intakes, and that gives them there advantage. They mimic the stock box, however have been better channeled, with a higher quality filter and less tubing. This design does not give the High RPM gains of a Cold Air, but it does not suffer from the low RPM losses either, also it manages to retain some of the sound characteristics of the stock Air box, rather then the “Angry Elephant” noise you get from a full Cold Air.

[Peregrine]

excellent job, Brent
Added to the DIY/FAQ Menu

[fadinglionhart]

Not sure if it's the right place to ask, but I remember when I put in the CAI, I had to reconnect some of the hoses with some sort of green liquid inside of it. Can you explain what that is and how important it is if you want to revert back to stock? Just for information's sake.

[clee109]

the coolant runs a relay along the intake in that box looking thing that connects to the intake piping. You just detoured around the relay by routing the coolant straight back to the engine. You do not need to reattach that to revert back to stock. Just leave it the way it is. Here's some pics of what I'm talking about and surely you are too:

Hey MemphisRheins, great post quick question...you said that a problem with cai is a stronger upper band hp gain, but you lose low-end torque right? Well if this is the case why would increasing the air flow decrease torque and how can you increase torque in the low and mid bands, thanx.

[SoCaliTrojan]

Originally Posted by MemphisRheins

The problem with the short ram is while the OEM intake sucked better colder air, the short ram draws from inside the engine bay, your engine hits some pretty high temperatures, This combination of limited and warmer air causes fuel-rich combustion mixtures that don't burn as well as they could.

Why do they make SRI's then? If they wanted the wider pipe, less bend, and aftermarket filter...people could just get something like the comptech icebox (for those who don't want a CAI).

A car going at 60 mph will have wind blowing on it at 60 mph (imagine a bug hovering in place, and then going splat on your windshield). Wouldn't this wind push all the hot air from the engine bay out of the rear-end of the hood? In the split second that the wind is in the car, does it have enough time to warm up significantly? Cars have grilles to let air through. Would this mean that a moving car with a SRI would have no ill-effects and that a car in rush hour traffic will be the only one to have the side effects? If so, then the SRI versus CAI debate is only in effect when taking off from a stand-still (and who needs the performance when you're stuck in traffic?).

Also, is it true that there's a slight increase in throttle lag for a CAI (when you floor it) due to the distance between the throttle body and the filter? IE: the mass of air is sucked up, and a vaccuum is momentarily created, so it takes time for air to reach the engine. (Or is this the concept that explains why low-end torque is reduced)

As for the OEM intake...would a simple removal of the resonator yield a difference (aside from the loss from its weight)?

If more air is the goal...what about a simple drop-in filter into the OEM box?

(just trying to get you to add more to your write-up ;-) good post)

yo how would i be able to take off the resonater??

[MemphisRheins]

Okay, lol looks like I got a few questions to answer here.

First to Coolshah, the engine sucks up more air at the higher RPMS, at low rpms it does not suck as well, the design of the CAI does not allow for air to just kinda float there like the OEM Air Box or Comptech/Mugen box's do... those designs keep more midrange power, however you do not gain as much in the high end... A Aftermarket Header and Especially the RT Cat will give you back the torque you lost and then some.

Now to socal...

The SR intake pretty much has the effect of streamlining the airs passage, it sucks air straight in and then shoves it right into the engine, The Comptech/Mugen Box works a lot like the OEM Box, however it has no baffles to disturb the air flow. As I explained above the air floats there to some extent, and the Mugen/Comptech box works better in the midrange, the SR like the CAI works better at the higher revs.

Now the engine heat question is a good one as well, yes id imagine in fact that the Air in the engine bay is circulated while moving, however the engine is in fact, really hot, even with this recirculation the air in the engine bay is significantly hotter then the air found below the bumper.... a alternative to the full CAI is buying a Heatsheild for a SR Intake

[MemphisRheins]

Originally Posted by e-amorosi

yo how would i be able to take off the resonater??

Take a look at the DIY thread i made for CAI install, the bottom half of the instructions deals with removing the resonator, IM Me if you need any more help

[That-TSX-Kid]

Just wondering, what is the best kind of Cold Air Intake for the '05 Acura TSX?
Estimated price of the part and any other details you can give would be great.
If I behave then I can get one... Thanks.

[MemphisRheins]

Its preference really, I have the K&N, Injen is the most popular

[That-TSX-Kid]

Okay, and the price?

[MemphisRheins]

Shop around, check our sponsors, check other sites, plenty of people have them or can order them, im not sure whos the cheapest at this current time

[That-TSX-Kid]

Thanks, Ill look at Injen first.

[jrhonda]

I have been searching for a CAI for my 07 TSX. I haven't gotten into mods at all and I am just learning. I can't seem to find a CAI online. any help? Will the K&N 69 Series Typhoon CAI work? it says that the only applicable years are 04-06 so is there a difference between the 06 and 07 that I am missing. the engine is the same, everything else is pretty much the same. Is there a minor space issue here?