The cold air intake debate
01-20-2004, 07:29 PM
#61
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I don't know where you heard that it is the "only" intake to not do any harm, but that is an unfounded claim. Intakes aren't quite in the same league as cranking your MBC to 22 pounds, but many of them are not helpful, while some won't hurt anything. "Working with the stock MAF" is not the same as "providing identical signals to stock for a given airflow." Also, the only times I have heard of intakes causing CELs is if they are really causing trouble, like detonation or misfires or over-rich conditions. There is no "intake malfunction" code like there is for removed cats. Anyways, if you like your intake, keep it.
01-22-2004, 11:06 PM
#63
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Some intakes do add some power, at least peak. But it wouldn't affect boost pressures directly, only if it was causing problems with what the ECU was seeing and making that change boost levels.
01-27-2004, 10:29 AM
#64
Originally posted by BAN SUVS
I don't know where you heard that it is the "only" intake to not do any harm, but that is an unfounded claim. Intakes aren't quite in the same league as cranking your MBC to 22 pounds, but many of them are not helpful, while some won't hurt anything. "Working with the stock MAF" is not the same as "providing identical signals to stock for a given airflow." Also, the only times I have heard of intakes causing CELs is if they are really causing trouble, like detonation or misfires or over-rich conditions. There is no "intake malfunction" code like there is for removed cats. Anyways, if you like your intake, keep it.
I don't know where you heard that it is the "only" intake to not do any harm, but that is an unfounded claim. Intakes aren't quite in the same league as cranking your MBC to 22 pounds, but many of them are not helpful, while some won't hurt anything. "Working with the stock MAF" is not the same as "providing identical signals to stock for a given airflow." Also, the only times I have heard of intakes causing CELs is if they are really causing trouble, like detonation or misfires or over-rich conditions. There is no "intake malfunction" code like there is for removed cats. Anyways, if you like your intake, keep it.
01-29-2004, 11:51 AM
#65
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Originally posted by gpatmac
Another fact is that the amount of heat that is post turbo (even post intercooler) is directly related to how much work the compressor side of the turbo had to do in order to compress however much boost you've asked it to. It doesn't matter a hoot what the ambient temperature is.
Another fact is that the amount of heat that is post turbo (even post intercooler) is directly related to how much work the compressor side of the turbo had to do in order to compress however much boost you've asked it to. It doesn't matter a hoot what the ambient temperature is.
clearly if you put 200 degree air into the turbo you will get hotter output temps than if it were 20 degress, providing the pressure ratio stays the same.
also, when measuring the temps "post intercooler" it is very clear that cooler ambient temperatures allow for a lower post IC temp.
ken
02-28-2004, 02:52 PM
#66
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I am New here but here goes. In the case of cold air intakes vs. short ram intakes, the shorter higher flowing intake wins. think about it. when drinking out of a straw, it is easier to pull the liquid through the shorter straw. so shorter with less bends will flow better. cold air does make more power but not as much power if you have MORE warmer air. i had a cold air untill i got my front mount intercooler, my fuel trim ran around -7. also a filter in the fender, where is the air coming from? yeah the 3 little holes beside the fog light (one large hole in the case of the wagon) that will cause an issue. its starving turbo for air causing it to overwork. a tip, take out the fog light, the filter sits right behind the fog light. one thing to consider, think about future plans, FMIC? go with the short ram, use the money you save and rig up some water spray, helps more on a hot day than a cold air intake.
another tip the washer tank on the wrx is the same that is used on wagons with dual pumps. another way to save money. check ebay for cold air intakes, you can find generic intakes for very cheap, buy one of them and buy the name brand filter of your choice. also the generic is the same size as the AEM tubing. all intakes should measure 2.5" otherwise it will throw the MAF meter off. thats all i have.
another tip the washer tank on the wrx is the same that is used on wagons with dual pumps. another way to save money. check ebay for cold air intakes, you can find generic intakes for very cheap, buy one of them and buy the name brand filter of your choice. also the generic is the same size as the AEM tubing. all intakes should measure 2.5" otherwise it will throw the MAF meter off. thats all i have.
03-01-2004, 11:09 AM
#69
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Originally posted by sleepinwrx
also a filter in the fender, where is the air coming from? yeah the 3 little holes beside the fog light (one large hole in the case of the wagon) that will cause an issue. its starving turbo for air causing it to overwork.
also a filter in the fender, where is the air coming from? yeah the 3 little holes beside the fog light (one large hole in the case of the wagon) that will cause an issue. its starving turbo for air causing it to overwork.
i take cold intake air over warm EVERY TIME.
ken
03-07-2004, 06:24 PM
#71
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Originally posted by sleepinwrx
I take where ever i can get the most air!!! True the colder the better, but like i said. MORE AIR is better!!!!
I take where ever i can get the most air!!! True the colder the better, but like i said. MORE AIR is better!!!!
03-07-2004, 08:26 PM
#72
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Originally posted by BAN SUVS
Not if it is hotter, which leads to detonation and/or retarded ignition timing. Besides, on a wRX, that isn't the point- it's your MAF values that are skewed which causes problems, and that's more important than anything else.
Not if it is hotter, which leads to detonation and/or retarded ignition timing. Besides, on a wRX, that isn't the point- it's your MAF values that are skewed which causes problems, and that's more important than anything else.
Last summer I pulled my stock resonator out from the front fender (at the suggestion of the author AG Bell, "Forced Induction Performance Tuning"....which shows some charts listing pressure drop the resonator caused on a Legacy B4 and a GC8 WRX, very interesting reading too), and bolted up a 3" diameter (at neck) alloy air horn from Summit in the fender well and dumping directly in stock air box. The next morning I made a run from the Fairfax area up Highway 1 north to Mendocino (CA for our out of state members) and the car DID run like a scalded cat! Once 3-3500 came up on the tach, the car lurched forward like it was being uncaged. I was kind of surprised.
But after getting nervous after reading some of the posts about removing the air-snorkle, I re-installed it today. And guess what-, the car feels a little sleepy. To be honest, I don't want to hear the intake roar of WOT and the hiss and the sneeze of the turbo and BOV. But the power did seem a bit stronger with the box gone. Enough to notice.
I thought about why this could be and still wish we could see some CFM numbers, or some pressure drop numbers from a flow-bench test, or from a manometer test on the stock air-scoop and air resonator. Where is the restriction? Are the 2.5L STi guys yanking the air-resonator out? And are they seeing any appreciable gains?
Is the stock scoop (above p/s fluid bottle, bolts to radiator header) the culprit? Looking at the design, I can see the air entering the scoop may have a tortured path once the hood is shut. Looking at the resonator in the fender, it doesn't look as restrictive. The WRX is 120 cu in. I think the 3" inlet of the stock resonator is probably sufficient (besides, look at the air horn that is molded into the top of the air-filter box).
Maybe cutting open one of the "walls" of the air-resonator would allow it to gulp more air (I guess through the vents next to and below the foglight?)
Any thoughts?
03-07-2004, 09:05 PM
#73
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Mathematical theory has a habit of falling by the wayside in real-world internal combustion applications. The reason is the real world is not a labratory with controlled environments. There are just too many other variables to take into consideration. Also, this is still the real issue with the WRX:
Originally posted by BAN SUVS
Besides, on a WRX, that isn't the point- it's your MAF values that are skewed which causes problems, and that's more important than anything else.
Besides, on a WRX, that isn't the point- it's your MAF values that are skewed which causes problems, and that's more important than anything else.
03-07-2004, 10:16 PM
#75
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Originally posted by BAN SUVS
The resonator mod works great because it improves intake efficiency without affecting MAF readings. That's why it's so highly recommended.
The resonator mod works great because it improves intake efficiency without affecting MAF readings. That's why it's so highly recommended.
Not the case?