cold air vs. ram air
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From: Pa......N. of Phily "Quakertown"
Car Info: 02-04R-STi PPG's FP-Green 391whp
Well I got a 02 RS with a Borla Headder, Randon Tech cat, and a Greddy EVO cat cack. "Sound is killer" It is an amasing system of free flowing art. It sounds great and my fule economy is up like 15-20% and Hp with the AEM short ram in ( a guess of 25-30 more that stock ) so in all it kicks butt in every way.......was also a very easy install to boot
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From: Reno, NV
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AEM (or any other brand) short rams do nothing. The AEM cold air intake, that runs through the fender, is ok, but not as good as Cobb or Gravelsport or Ganzflow.
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When you start modding, the total power gains tend to be more than the sum of the parts, but on any given car, a short ram that draws air from under the hood is less powerful than a true cold air intake.
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Turbo or no, it's hard to argue with thermodynamics. Warmer air contains less O2 for combustion than (relatively) cooler air does, regardless of what type of combustion is taking place or what is catalysing it.
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not really. the reason a ram style would be best for turbo is velocity. thats one of the reasons rally cars use them. because of all the piping involved in a true cold air intake, the engine can't pull it in as fast.
for example, when you breathe in air. try filling your lungs as quickly as possible. then put 3ft of 3in tubing around your mouth and try again. see my point?
velocity creates power the same as lower temperature creates power.
for example, when you breathe in air. try filling your lungs as quickly as possible. then put 3ft of 3in tubing around your mouth and try again. see my point?
velocity creates power the same as lower temperature creates power.
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Velocity is a function of diameter, not length. Blow through a 12" piece of 1" tubing, and a 12" piece of 2" tubing to see why. Volume is the oposite, and rally cars need large volumes of air. Also, smaller intake component volume gives better throttle response, which is even more important in rallying than 2 horsepower.
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sorry my physics or whatever aren't up to par. but you see my point as to why a short ram would be better for turbo'd cars.
anyway, the fact is that a short ram is still better than stock and does add power even if it's not as much as a cold air setup.
anyway, the fact is that a short ram is still better than stock and does add power even if it's not as much as a cold air setup.
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Okay, don't take my word for it. But do yourself a favor and email Shiv at Vishnu and ask why he won't tune cars with aftermarket intakes. He can explain it better than I can.
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From: Elkton, Virginia
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I agree with BAN SUVS. Cold, denser air is always better than hot air coming from the engine bay, regardless of velocity. You mentioned something about rally cars using a short ram for velocity. True, but more hot air isn't better than say a little less cold air. If I remember correctly, an engine gains 1% HP, not 1 HP, from every 10 degrees dropped. Here is an opinion, but lets see if it floats. I don't know much about rallying, but wouldn't it make more sense to put the air supplier under the hood away from dirt, snow, water, and other debris just for that simple, yet important reason? I think BAN SUVS said the reason for a short ram on rally cars was for throttle response, but this was maybe another facet they considered.
-Charles-
-Charles-
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imprezaVA, i think you just said what i've been trying to say.
if you'll also notice that i said it's one of the reasons they use ram air. the other is the water, dirt, snow, etc.
one way to bring temps down is to peel back the rubber on the top corners of the hood about 7in. this is something they do in japan to lower underhood temps. if you also remove the vent covers on the hood it will help lower temps as well.
i think that when it all comes down to it, it depends on what your future plans are. if you plan to stay off the track and have no intentions of going turbo, a cold air would be best. if you plan to add a turbo later or spend time at the track, ram air would be best.
if you have a money tree growing in the back yard then
1. share
2. buy whatever
if you don't and plan to go turbo it might be smarter to spend $100 less on a ram air so you don't end up losing too much when you switch.
juz my .02
if you'll also notice that i said it's one of the reasons they use ram air. the other is the water, dirt, snow, etc.
one way to bring temps down is to peel back the rubber on the top corners of the hood about 7in. this is something they do in japan to lower underhood temps. if you also remove the vent covers on the hood it will help lower temps as well.
i think that when it all comes down to it, it depends on what your future plans are. if you plan to stay off the track and have no intentions of going turbo, a cold air would be best. if you plan to add a turbo later or spend time at the track, ram air would be best.
if you have a money tree growing in the back yard then
1. share
2. buy whatever
if you don't and plan to go turbo it might be smarter to spend $100 less on a ram air so you don't end up losing too much when you switch.
juz my .02
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Originally posted by ImprezaVA
I agree with BAN SUVS. Cold, denser air is always better than hot air coming from the engine bay, regardless of velocity. You mentioned something about rally cars using a short ram for velocity. True, but more hot air isn't better than say a little less cold air. If I remember correctly, an engine gains 1% HP, not 1 HP, from every 10 degrees dropped. Here is an opinion, but lets see if it floats. I don't know much about rallying, but wouldn't it make more sense to put the air supplier under the hood away from dirt, snow, water, and other debris just for that simple, yet important reason? I think BAN SUVS said the reason for a short ram on rally cars was for throttle response, but this was maybe another facet they considered.
-Charles-
I agree with BAN SUVS. Cold, denser air is always better than hot air coming from the engine bay, regardless of velocity. You mentioned something about rally cars using a short ram for velocity. True, but more hot air isn't better than say a little less cold air. If I remember correctly, an engine gains 1% HP, not 1 HP, from every 10 degrees dropped. Here is an opinion, but lets see if it floats. I don't know much about rallying, but wouldn't it make more sense to put the air supplier under the hood away from dirt, snow, water, and other debris just for that simple, yet important reason? I think BAN SUVS said the reason for a short ram on rally cars was for throttle response, but this was maybe another facet they considered.
-Charles-
1) Far less dirt, brush, rocks, small animals etc. under there.
2) Since power is determined by the 32mm, the warm air under there is perfectly capable of supporting the 300 or so horsepower they are making, so the cleaner warm air is better than the cooler 'dirty' air. Throttle response, while crucial to rallying, is probably less of a concern than thick billowing cluds of dust often seen in summertime west coast rallies.
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From: Buckley
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could someone enlighten me on what a "short ram air intake" is?
when i think of ram-air. I'm thinking F1. And the reason for ram air is to try to generate a small ammount of presure. Why would you even bother when the turbo is generating far more pressure into the engine than you could ever hope for on a ram air intake.
when i think of ram-air. I'm thinking F1. And the reason for ram air is to try to generate a small ammount of presure. Why would you even bother when the turbo is generating far more pressure into the engine than you could ever hope for on a ram air intake.