Doesn't this kinda bother you?

[truwarrior]

I was checking 3si.org and this one guy did some testing with intake temps and cold air intakes. Basically with just a open element intake his temps where from like 88-113 degrees.

He then cut his carbon fiber hood the made a air box for the air filter. This temps went from a max of 113 to like low 90s or high 80s.

That's a big difference. Ever since I got my apexi intake I think it sounds cool and stuff but I wish I was still getting the air from the fender. The apexi intake does come with a heat shield but do you think I'll benefit any more from geting one of those other heat shield that attach to the right of the filter? I want my cold air back!

 

[GSX24PSI]

you have a GST...sucking air from the fender will make maybe a tad difference,because the turbo will heat it up,thats what an I/C is for.

 

[Spinall4]

Originally posted by GSX24PSI
you have a GST...sucking air from the fender will make maybe a tad difference,because the turbo will heat it up,thats what an I/C is for.

I think this is not exactly right- I look at it this way. You turbo heats up air beacuse of the ideal gas law, and the fact that its not 100% efficent. So lets say that the avrage turbo is 70% efficent- that means that theres goint to be a temp rise of 30% over what it normaly would be beacuse of the ideal gas law (PV = nRT). So, your air is going to be hotter after the turbo than before it beacuse thats was a gas does when you compress it- but on top of that you have the turbos inefficency working against you- in this case some where around 30%. So, with out even taking into acount temp rise from the ideal gas law lets look at some raw numbers.

I have a cold air box on my car I made out of about 20$ worth of stuff from home depot. My air temps droped from 50-60 degrees above ambeint to about 3-4 degrees above ambeint. Now, lets factor in that extra 30%- the after turbo temp is up about 3.5 degrees with the cold air box, with out the cold air box its up 71.5 degrees (keep in mind that this is with out the temp rise that has to occur beacuse of the ideal gas law its self). So you just took out 68 degrees that your puny stock i/c doesn't have to deal with(and we all know how bad the stock i/c gets heat soked). Not bad for a couple hours of work(at most) and maby 20$ worth of stuff from home depot.

 

[Defiant]

It's all fun and games until someone brings out equations and numbers.

 

[BoostinAWD]

Someone's gotta set them straight. I completely agree.
Much better to start with cooler air.

 

[Spinall4]

Originally posted by Defiant
It's all fun and games until someone brings out equations and numbers.

The sad part is I rember back in 10th grade chemistry thinking "where in life am I ever going to use this"

 

[MrPikolo]

My brain hurts, i havn't had to think that hard since college physics in high school, i'm going to lay down.

So putting a heat shield like in a vfaq would help out moer than just a lil bit.

 

[RipperXX]

commin since would tell you that if you geting colder air into the engine dispite the fact that it will gain heat from the intake and pressurization it will be lower than with warmer air....

no need for math here... just common since... but if you want to get every last ####ing .001hp out of the engine yea do the math...

 

[sids]

a heat shield drops intake temps by 50 degrees? Is it that much, I thought it should drop it 10 degrees at the most, well then again, most fot he heat shields are just metal boxes that isolate the filter element formthe rst of the engine, but the surrounding temp in the box would also be way above ambient since it is enclosed, the only way I figured for cold ait intake for our cars was to get rid of the headlight and fashion a fiberglass ram air scoop

<img src="https://www.compass.com.ph/~sca/ramair.jpg">

 

[GSX24PSI]

that and maybe it gets hotter because the engine is spitting out extremely hot exhaust into the turbo...but yea stick with the apexi intake because it "sounds cool"...

all that i am saying is it will not make a big enough difference to feel while you driving, my buddy made a sheet metal one for his TSI, but i am sure if we broke ever thing down to the rediculus it will look good on paper.

 

[Spinall4]

Originally posted by sids
a heat shield drops intake temps by 50 degrees? Is it that much, I thought it should drop it 10 degrees at the most, well then again, most fot he heat shields are just metal boxes that isolate the filter element formthe rst of the engine, but the surrounding temp in the box would also be way above ambient since it is enclosed, the only way I figured for cold ait intake for our cars was to get rid of the headlight and fashion a fiberglass ram air scoop

<img src="https://www.compass.com.ph/~sca/ramair.jpg">

Mine isn't just sheet metal, its sheet metal with a layer of insulation on each side. I'm not sure your car would get the exact same results as mine, but I figured it couldn't hurt. I figure if your droping intake temps aprox 68 degrees, thats giving you at least 5-6 hp. Not bad for 15-20$. No you proably can't feel the difference it makes, but if you do ten little things that add 5 hp each, theres 50 hp and you sure can feel that.

 

[Defiant]

I want to know where to pick up something to measure intake temps with. VOM probe? Hi-temp electronic thermometer?

 

[JayHass]

Originally posted by GSX24PSI
that and maybe it gets hotter because the engine is spitting out extremely hot exhaust into the turbo

Um, no you already got the answer. It's a law of physics. An air compressor does the same thing. In fact our shop beast is intercooled between stages. When you compress air, you make heat.

but i am sure if we broke ever thing down to the rediculus it will look good on paper.

Come on man, that's a lame argument. Just admit you didn't have the right answer and move on. It doesn't just look good on paper, this is fluid dynamics 101 and a principle anyone with a decent amount of turbo experience should know.

The cooler you can make the air going into the turbo the better. Compressor delta T, and therefore compressor work, is directly
proportional to compressor inlet total temperature. It's that simple.

 

[brads]

You already have the temp at the MAF, assuming you still have a MAF.

Otherwise, a K type thermocouple(same used in EGTs) will work well.

Brad

Originally posted by Defiant
I want to know where to pick up something to measure intake temps with. VOM probe? Hi-temp electronic thermometer?

 

[GSX24PSI]

youre good

 

[Smokin GST]

the temperature of air going into my MAS is ~80º F. tested this with a snap-on OBD-II code-reader hooked up to my car when the temp was about 75º out. i have a supra IC, and i hacked the shit out of my inner fender to route air in. pulled that plastic snorkel out from above the plastic fender guard so that oval hole that your orignal air box sucks air through doesn't have any restrictions. also cut out the metal under the air filter.