Fresh Air Intake Thoughts

[anticon]

Last night I pulled the four screws on the top panel where the air is brought into the airbox and tried to get a good look at exactly where the air would come from if everything is stock without a hole cut in the shroud. I tried to pull the panel off completely, but it is somehow attached to the front bumper and I wasn't willing to pull hard enough for fear of breaking it (that is a very typical outcome for me.) Anyway, I found that the area under the panel is pretty well sealed up and is fairly large, it runs a little over the length of the grill and is probably 3 inches deep and 4 inches wide on average across it. It looked like there were a few places that air could get in; mainly from each end under the headlights/above the crash bar where it just opens up completely, it could also get in from where the hood latch comes through, and the only other spot I saw was it looked like there was a small gap in places on the front edge that would allow air in from the near the grill. All of these locations were in front of the radiator, although the biggest holes on the ends under the headlights still opened up under the hood. Either way most of the air would come from fairly indirect locations, and most likely from hot air under the hood. I don't disagree that cutting a hole in the shroud would allow more fresh air, but without sealing off the other areas it is still getting some hot air in, mainly from the ends under the headlights. I would assume even with the ST200 airbox it is still getting air from here along with the fresh air hole in the bottom (unless you seal up the snorkel part).

This makes me think that if I want true fresh air without any chance of under hood engine air I would want something like the VelossaTech Big Mouth with a sealed stock box.

OR

I think the best "no cutting" method would be an ST200 airbox with the snorkel on the top of the airbox sealed up. Thoughts?

VelossaTech has a post in this thread with a couple images that kind of allow you to see how the cowl would vent. I sketched on one to show what I was thinking.

http://www.fiestastforum.com/forum/t...-thread!/page7

 

[koozy]

waste of effort, inter-cooler performance and efficiency is where the focus should be at IMO.

 

[anticon]

waste of effort, inter-cooler performance and efficiency is where the focus should be at IMO.

So are you saying that instead of worrying about getting fresh ambient air first, just let the intercooler take care of the cooling before it hits the engine? This would make sense if the intercooler can cool the pressurized air to the same temperature regardless of what the temperature of the air was before being pressurized in the turbo. Has anyone tested this?

I just ran a google search for intercooler vs cold air intake, and it looks like this question has been asked across many different forums and platforms. However, I didn't see any actual testing or results.

Part of me thinks that the colder the air is coming into the turbo, the colder (and more more importantly more dense) it will be coming out, and the colder it will get going through the intercooler. However it also makes sense that if the intercooler is big enough it can still only cool the air to ambient temp.

I think the real question is if the air is cooler going into the turbo, can it be compressed more and thus be more dense?

I found this post from [MENTION=1333]BoostBumps[/MENTION] which makes it sound like IAT is a factor.

http://www.fiestastforum.com/forum/threads/2731-BoostBumps-RaceRed-Build-Thread?p=81119&viewfull=1#post81119

 

[zanethan]

An intercooler will certainly be the best way to cool intake temps but I have to believe that pulling in cooler air also helps. That being said gains will be minimal at best.

 

[Olephart]

If I want fresh air, I usually open the window, or ask my wife to stop farting.

 

[jtehh]

So are you saying that instead of worrying about getting fresh ambient air first, just let the intercooler take care of the cooling before it hits the engine? This would make sense if the intercooler can cool the pressurized air to the same temperature regardless of what the temperature of the air was before being pressurized in the turbo. Has anyone tested this?

I just ran a google search for intercooler vs cold air intake, and it looks like this question has been asked across many different forums and platforms. However, I didn't see any actual testing or results.

Part of me thinks that the colder the air is coming into the turbo, the colder (and more more importantly more dense) it will be coming out, and the colder it will get going through the intercooler. However it also makes sense that if the intercooler is big enough it can still only cool the air to ambient temp.

I think the real question is if the air is cooler going into the turbo, can it be compressed more and thus be more dense?

I found this post from [MENTION=1333]BoostBumps[/MENTION] which makes it sound like IAT is a factor.

http://www.fiestastforum.com/forum/threads/2731-BoostBumps-RaceRed-Build-Thread?p=81119&viewfull=1#post81119

Right now I have a VT Big Mouth and Whoosh Intercooler. I have been switching between my Revo intake (standard "hot-air" intake with heat shield, but is not truly sealed) and my stock airbox with K&N drop in. I have probably gone back and forth about six times in the last month trying to figure out what is working best for intake and charge temps. As stated above, the charge temp is the one that counts. But certainly, if your intake temp is lower, your intercooler doesn't have as much work to do to reduce temps and in theory, cooler intake temps would lead to cooler charge air temps.

My anecdotal findings based on watching my temps obsessively on the Cobb AP as I drive is that in very warm weather, it just doesn't seem to matter. The intake temp does get higher on my Revo, but the charge temps are a few degrees lower. With the stock airbox, intake temps are lower, but the charge temps are still about the same. So with the stock box, the charge temps end up being very close to the intake temp. And on a day like today (was close to 100 here in Delaware), I ran with my Revo on a fairly long trip and the intake was between 105 - 110 when I was moving and the charge temp was at 100.

I just don't feel like the intake temps are really causing my charge temps to rise/fall. The IC does what it can based on how quickly it can dissipate heat and in warm weather it just has a harder time. But feeding it air that is maybe 10 degrees cooler doesn't seem to help.

Again, totally anecdotal. But I was also on the "oh noes, I need the coldest air possible" train and I just haven't seen it. That stock box is nice and sealed, is plastic, and I have a big mouth pulling in air from the front of the car. And yet, my charge temps are the same with my Revo (and I'm really not sick of the sweet sounds of the Revo ). So throw my vote in with [MENTION=235]koozy[/MENTION] - your FMIC is the best way to get cold air into your engine.

 

[anticon]

Thanks that is really great input. I'm glad somebody is running some current real world tests.

 

[HBEcoBeaST]

People that go crazy against open air elements don't realize how much a turbo heats the air. Yea a closed box intake will pull in cooler air while you're stopped, but that cooler air is pressurized by the turbo which heats it up again. Your intercooler is more important than your intake. Especially with an upgraded turbo it's more about how much air is available to be sucked in than the initial intake air temp.

Sent from my Pixel 2 using Tapatalk

 

[M-Sport fan]

^^^It is not just the air being pressurized by the compressor (and therefore super-heated anyway), but also the HEAT SOAKING that the compressor imparts to said air as it is moving through it as well, from being so close to so many sources of HIGH radiant heat (where I can see the hotly debated turbo blankie discussion coming into play).

I've often wonder IF it even matters if the intake air before the compressor were 50*+ lower than ambient, that it would actually lower the charge air temp going into the IC's inlet?

 

[Spaceman_Spiff]

^^^It is not just the air being pressurized by the compressor (and therefore super-heated anyway), but also the HEAT SOAKING that the compressor imparts to said air as it is moving through it as well, from being so close to so many sources of HIGH radiant heat (where I can see the hotly debated turbo blankie discussion coming into play).

This sounds like a good place to mention something that's been on my mind for a while - I read about a high-HP car (I can't remember which one, pretty sure I read it in the last year or so) that had a door that would open under certain conditions in order to allow ambient air to pass over the [supercharger/turbo] in order to cool it off at high speeds. Could something like that benefit our tiny little turbos that are stuck in the back of the engine bay away from all the cool air?

 

[anticon]

I found this thread with some tests by 2jr back in 2014. They seem to show that higher IAT decreases power. They don't show what the charge temps were though.

http://www.fiestastforum.com/forum/threads/1076-Fiesta-ST-Intake-Dyno-Tested?p=13494&viewfull=1#post13494

 

[A7xogg]

I found this thread with some tests by 2jr back in 2014. They seem to show that higher IAT decreases power. They don't show what the charge temps were though.

http://www.fiestastforum.com/forum/threads/1076-Fiesta-ST-Intake-Dyno-Tested?p=13494&viewfull=1#post13494

Check out this thread
http://www.fiestastforum.com/forum/threads/16698-Dizzy-Tuning-Intake-Tests

 

[jtehh]

I found this thread with some tests by 2jr back in 2014. They seem to show that higher IAT decreases power. They don't show what the charge temps were though.

http://www.fiestastforum.com/forum/threads/1076-Fiesta-ST-Intake-Dyno-Tested?p=13494&viewfull=1#post13494

Well, yeah. If your intake temp is 140 degrees. I only see that temp if sitting at a stoplight or serious gridlock on a 90+ degree day. As I mentioned above, even with ambient temps above 90 my "hot-air" intake temps peaked at about 110 while moving at least 30 MPH. I think we all agree that a very large variance in IAT will raise charge temps and make a difference in the power. For example, on the flip side, when the seasons change around here and we get into "boost weather". There is a difference I can feel.

But - in both extremes, will the type of intake really matter? That is the part I just haven't seen. The IAT difference between the intake types isn't a 50 degree swing. My stock box IATs get above ambient too.

 

[anticon]

And then i find this...

http://stratifiedauto.com/blog/the-effects-of-intake-air-temperatures-on-turbocharged-vehicles/

 

[GAbOS]

This sounds like a good place to mention something that's been on my mind for a while - I read about a high-HP car (I can't remember which one, pretty sure I read it in the last year or so) that had a door that would open under certain conditions in order to allow ambient air to pass over the [supercharger/turbo] in order to cool it off at high speeds. Could something like that benefit our tiny little turbos that are stuck in the back of the engine bay away from all the cool air?

This is what the center intake vent on EvoX's do.

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[danbfree]

Still think that unless you plan to drive through a flood zone there is literally no reason not to at LEAST cut the hole in the shroud where a Big Mouth would pass through, it is just too damn sealed up for any good, maybe it's for aerodynamics/MPG's? I'm seeing better charge and overall temps after having done it... not HUGE differences, but when you can help keep intake air temps down every little bit helps with our cars that have marginal factory cooling.

 

[koozy]

The shrouds purpose is to seal up air from escaping and to funnel it directly into the heat exchangers (AC condenser, radiator). It's been a topic in the past where members who completely removed the shroud noticed a significant rise in coolant temps, so much that it was imperative to put it back on. Cutting it up to put a scoop that occupies ~40% of real estate can't be good for the heat exchangers, but people do it. There's risk and reward, a fine balance.

 

[danbfree]

The shrouds purpose is the seal up air from escaping and to funnel it directly into the heat exchangers (AC condenser, radiator). It's been a topic in the past where members who completely removed the shroud noticed a significant rise in coolant temps.

I have no intentions of removing the entire shroud and have noticed lower temps so I'm good just keeping it this way then... thanks, I guess... heh... To clarify, it hit 98 where I was yesterday and after multiple WOT runs my coolant temps never exceeded 215, so I guess I'm good... charge temps once hit 140 with stock IC, but that's another story.

 

[Kalter]

My setup is the ST200 box with the VT big mouth. If I'm moving, the intake and charge temp are basically ambient (except if I'm really flooring it, then charge raises a bit). From my personal experience, a big mouth makes a good difference in intake temperature, but maybe that cutting a hole similar to what the big mouth needs might be enough, I do not know. Since I installed my J-line FMIC at the same time as the big mouth, I can't tell if it made a difference in charge temp, but as I said, it made a difference of a couple of degrees for the intake.

I did install the ST200 box relatively recently, and this one also made a difference in intake temperature, but much less than the big mouth. I would not be surprised if I had done the opposite that I would get the same results, meaning that in term of intake temperature the big mouth and the ST200 box are basically equal and gives minimal improvement to each other.

BUT my reason for the ST200 box was not for temperature, it was for airflow. With the added hose, it's impossible to not have more air coming in. The stock hole is so small. I'm sure it was not a limitation for now, but it doesn't hurt to have a bit more.

I recently opened up the intercooler opening a bit more and it made another small difference in intake temp (the j-line is higher than stock, but not as wide). I even had charge temp a tad lower than intake a couple of times.

Anyway, the most important is the FMIC. It doesn't hurt to have lower intake temp, but it might not even affect charge temp, which is the important one.