After i put my ebay short ram intake on, with a weapon R cone filter ive been nothing but disappointed. I immediately felt/heard a difference, loss of torque for sure, and after testing for awhile, theres lots of power loss after a long drive. Then i saw the dyno of the guy who did a short-ram/type-s/stock/aem-v2 intake swapping test. The stock intake is just as good as the type-s and v2 (2hp different which could be do to different variables). All this made me think, why do companies make intakes made out of aluminum? Aluminum transfers heat great, exactly what you dont want. I can put my hand on my aluminum intake after i drive and its completely heat soaked and pretty dang hot. The stock rubber intake is NOT like this and is also a cold air intake. Im putting it back on with a K&N. Dont tell me the V2 short ram is gonna make a world of difference, this is proven not so.
this is true. however it depends on your car. if you have some run of the mill ****can rigging up a cold air, aluminum intake will make a difference. most likely the company didn't care in the design and just lets the intake draw air from the engine bay without any notion for performance. although that may be different these days.
honda actually went out of the way to properly design the air intake on the prelude. i considered a aftermarket intake until i realized its just about looks. when i took off the bumper i realized there was A LOT more to the intake than just a rubber tube and a plastic housing, because before i thought the filter housing simply pulled air from that area in the corner of the bumper.
instead there's an entire contraption down there that better stirs the air and compresses it before passing it up through the filter. its even smartly designed since it doesn't just suck up air from that spot but channels in air from behind and above the wheel well, well away from any heat or the engine.
what really made me smile was seeing a tiny little air powered valve unit, which is controlled by the VTEC to open up a secondary channel in the intake unit thing to suck up more air and give the prelude that signature "roar."
I am going to buy a stock intake next paycheq. My car came with the worst aftermarket intake ever. And reading Shimee's post was even more helpful in the decision.
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1993 JDM Subaru WRX 220whp (Daily driver)
2000 CDM Honda Prelude base (SOLD)
1991 JDM Toyota Celica GT-FOUR RC (SOLD)
the type s is probably the best but that black box you talk about is pretty useless and is used make make your car quieter you get better performance by taking it out and better sound and gives about the same power as a cold air except its free!
In 99% of driving situations, the material an intake is made out of is irrelevant. Air is being pulled through it so quickly and in such large volumes, there isn't enough time for the material an intake is made out of to affect the incoming air temperature.
Same goes for the placement of the filter . . . Again, the engine draws a LARGE volume of air, the tiny amount of heated air hanging around under the hood is nowhere near enough to feed it. So what the engine gets is pretty close to ambient.
Take a look at some IAT readings, you may be surprised. In fact, there was a member on here who did a pretty good comparo of different intake types & their affect on IAT . . . I'm not having any luck finding it now, though. Anyone know where/what that was?
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In 99% of driving situations, the material an intake is made out of is irrelevant. Air is being pulled through it so quickly and in such large volumes, there isn't enough time for the material an intake is made out of to affect the incoming air temperature.
Same goes for the placement of the filter . . . Again, the engine draws a LARGE volume of air, the tiny amount of heated air hanging around under the hood is nowhere near enough to feed it. So what the engine gets is pretty close to ambient.
Actually I have definite evidence because I can actually measure IAT via my scangauge in the car.
1. OEM box gets slightly higher (but not by much) readings while on the highway.
You do need to realize at idle it will raise the temp a little bit but the minute you start going, it will cool down quickly or to near ambient outside temp.
2. K&N short ram with heat shield, pretty much the same.
I would say the only difference is if you've turned off the car for awhile and the intake has had time to soak up the engine bay heat. I did notice the SRI will cool down a bit faster but again, not by much and this is me actually looking at the dang gauge.
Also I didn't feel a difference in anything performance wise from either setup, just noise.
So you can believe what you want to believe, but you could do it EMPIRICALLY yourself and probably come to the same result.
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
In short.. at WOT the material of the intake doesnt effect the air temp, but when its heatsoaked and not at WOT it does.
Quote:
The issue of heat absorption with an intake system has a degree of validity, however we have found that too much emphasis is placed on material selection, instead of the real issue of tuning the system. Our systems feature a unique shape and diameter because this is what we found to make the most useable torque and horsepower for each individual application in testing. However, for the purposes of this discussion, we will limit it to why we choose to make our systems from aluminum and the effects of heat absorption on all materials. If you do not wish to review all of this information right now, a quick synopsis of this discussion is outlined in the following bullet points, with complete topic discussions below:
* We use aluminum to eliminate any chance of the system rusting, and it's lighter than steel
* We limit our use of plastic because this material absorbs some of the sound energy we work to create in the inlet duct
* Whether or not an inlet system is made from aluminum, steel or plastic, the thermal conductivity of the duct material has little effect on engine power
* The rate at which air travels through the inlet path under open throttle, when one is asking the engine for maximum power, negates the effect of material heat soak, regardless of the material
We use aluminum—or a combination of aluminum and plastic plenums for throttle-body-injected applications that require a special plenum—for every intake we produce. This eliminates any chance of rust occurring on the inside of the inlet pipe. We have seen chrome-plated steel systems whose inner diameter became rusted over time, causing flakes of rust to travel along the inlet path. We also choose aluminum because of its lightweight properties. Heavier components place higher loads on the brackets they are attached to—or even worse, to the pipes they are attached to. We combine our lightweight aluminum design with a flexible coupling device we call a soft mount that connects the intake system to the body of the vehicle. In addition to the soft mount, we use doublers at the point where the mounting bracket is welded to the pipe for additional strength.
We limit our use of plastic because this material absorbs some of the sound energy we work to create in the inlet duct. Although we use the best plastic material for our plenums, it is still not as resilient and does not retain the visual appeal of aluminum over long-term use. Because we have to use plastic on throttle body applications, we take extra precautions to ensure that the aluminum retaining ring that attaches to the throttle body is anchored securely into the plastic plenum; this is done by making an interlocking mechanical link between the plastic and aluminum.
Whether or not an inlet system is made from aluminum, steel, or plastic, the thermal conductivity of the duct material has little effect on engine power. We have found that the tuning of the pipe, in addition to providing the coolest inlet air source, are the keys to making useable power. We perform engine inlet-air-temp studies when developing each application to determine the coolest location for sourcing inlet air. In addition to this, we determine the safest location for the inlet source to protect it from highly dusty conditions and water. To this end, we provide a stainless-steel heat shield to help minimize heat soak into the inlet area, as well as to provide protection from dust, dirt and mud.
At light throttle opening, air speed and airflow at the inlet system are relatively low. The high residence time of air in the inlet while at low-throttle settings will increase inlet charge temps when materials with high thermal conductivity are used. Typically, when someone is at light throttle they are not asking the engine to make power. Most likely, fuel economy is the issue.
When the throttle is fully opened however, air speed and airflow increase considerably. Typically, the inlet air speed of a 5.7L engine with a four-inch duct at full throttle is 34 feet-per-second, based on a volumetric efficiency of 70% and an engine speed of 3,000 rpm. Most inlet systems for every intake manufacturer for this engine are 30 inches or less. This means that the air in the duct of a 30-inch inlet length on this engine at the given rpm is 1/10th of a second—hardly enough time to transfer an appreciable amount of heat into the air stream on any system.
Basically, the rate at which air travels through the inlet path under open throttle, when one is asking the engine for maximum power, negates the effect of material heat soak, regardless of the material. We hope that this helps to clear up the issues of material heat absorption in intake systems.
In 99% of driving situations, the material an intake is made out of is irrelevant. Air is being pulled through it so quickly and in such large volumes, there isn't enough time for the material an intake is made out of to affect the incoming air temperature.
Same goes for the placement of the filter . . . Again, the engine draws a LARGE volume of air, the tiny amount of heated air hanging around under the hood is nowhere near enough to feed it. So what the engine gets is pretty close to ambient.
I still think this is nonsense. Theres more than a tiny amount of heated air. That heated air is being manufactured right under your hood, it doesnt just go away when the engine sucks it in.
^so that begs the question, why bother with a CAI or aftermarket part in general.
You want more power but if you aren't at WOT, you won't be making that power. So is it more of an issue of being more efficient?
I've gone on my soapbox before about intakes. To me, the price / ease of installation have made it a normal choice for any aftermarket enthusiat. That also makes it such a big topic that in the end, its just an intake. Tip of the iceberg for bigger and better things. I see so much discussion about intakes that it's vastly improportional to the amount of gain they produce.
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
I think intakes are hyped. Like was mentioned before, the manufacture goes through a bit of trouble to design an intake a certain way. When i buy an intake for 200$ or more id like to see some decent gain, or what is it worth. You can buy a nice catback for that much. Many people throw on a short ram and think since it looks good and sounds good it must be good, a nice placebo effect. In my car with a short ram i felt a loss of power when its hot out for sure. In fact, i immediately felt a loss of power through low rpm, although it did sound like the engine was breathing better.
Its one of the first mods people waste money on, and one of the last that they should. I would bet that you could do tons of other engine modifications (cam, head, intake man, whatever) and still not have much (if any) loss because of the stock intake.
^so that begs the question, why bother with a CAI or aftermarket part in general.
You want more power but if you aren't at WOT, you won't be making that power. So is it more of an issue of being more efficient?
I use my car as a daily driver and try to spend very little time at WOT. But would i sacrifice 2hp all the way up to 5k rpm if i could gain 2hp after 5k rpm. Absolutely not, most of my driving is under 5k rpm. AEM says at WOT the air travels fast enough for heat soak to not matter, but thats not absolutely true either. The air speed is quite different from WOT at 1k rpm to WOT at 5k rpm.
MOST people will not spend much time above 5k rpm. If thats not believable, check the oil consumption threads where people say how many times a week they are in VTEC.
In a stock airbox, the flexible material will cause more turbulence in the incoming air. However like you said the material is better in the stock airbox. Ideally i guess you would want a plastic air intake that is hard plastic but then there is still the debate on cold air vs short ram.
I think intakes are hyped. Like was mentioned before, the manufacture goes through a bit of trouble to design an intake a certain way. When i buy an intake for 200$ or more id like to see some decent gain, or what is it worth. You can buy a nice catback for that much.
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