Remodded my intake
 

Out at hawthorne , i was feeling around the filter part of my K&N Air intake after some of the runs and i discovered that the entire area was very very warm. (and it was only 65 ish out ) I had Nick check it out also. then I noticed that there was a small gap between the K&N 'heat shields?' and where you could see the header/ exhuast manifold type stuff.

....
So flash forward to today

I drove my car over to ansels and i was very very easy on her. i didn't spool up past 0 boost, nor did i go over 3800 rpms. as soon as i got to ansels i popped the hood and we felt the cone air filter, it was a bit warm. warmer then the intercooler. (air temp was about 62 ish out !)

So i pulled out a small peice of sheet metal i bought monday. And with help from rubberbuscuit i bent, folded, tore a peice into shape to complete the heat shield. we even drilled a hole in the sheet metal and reused a factory bolt location. Ansel found a small scrap of unsed weather liner that came with the K&N and sealed up one last little gap.

then i took my lovely stock subaru snorkel. And attacked it with a Razor blade. :D Cut a 'precision air Duct' on the side of it. and fumbled around with the plastic bit i cut off for a little while to try and block the factory outlet of the snorkel. it wasn't really staying in there. :( but Luckly ansel had a box in the trash and i cut a bit of that cardboard up and fit it in nicely to deflect the air flow right towards the K&N Cone. :) I planned to use a bit of Duct tape, on that air Duct later on, but i gave the snorkel a few good shakes and the cardboard is very secure.

then we take it for a test drive. I went to the only 55 zone in tahoe and drove it hard (drove it hard on the way there too) kept it over 4K the whole time. we pulled over in a parking lot and felt the cone. COLD !!! Very cold (the air temp was now 54 ish) but wow was that filter COLD. the outside of the new heat shielding was WARM. and the intercooler was Cool. :D

$3 mod :) gotta love it ! damn tahoe kids ! :lol:

Ansel will post some pics tomorrow.

Some people will say it doesn't really matter if your sucking hot air in since it's all getting heated by the turbo. Who really knows how big of a difference a mod like that will make? Certainly can't hurt and I give you an A for effort. :cool:

the funny thing is i was one of those people who said it shouldn't matter if its hot or cold air .
Mostly it was freaking me out a little bit that the air filter was very warm to the touch.

yo. as promised.

http://i3.tinypic.com/1196yl2.jpg
tools used by profesional fabricators.

http://i3.tinypic.com/1196yaw.jpg

http://i2.tinypic.com/1196wx2.jpg

i am not a mspainter.

oh and about the tempature, i can vouch for the external filter temp decrease. after a soft drive before fabrication the filter was warm to touch. after a spirited drive, after shield fab, filter feels like cold. no scientific temp reading taken, but it should be signifigant.

when the turbo heats up air, it will heat the air coming in. therefore if air is 10* cooler should be approx 10* coming out. theory fucked up? i dont know shit? i don't know. i do know that i'm late for work.

True, if the air into the turbo is colder, the air comming out will also be colder than it might be otherwise. However, your car is intercooled. If the intercooler is properly setup and not heat soaked, it should cool the intake charge to near ambient even if the intake is warm.

For example:

intake -> 100* -> turbo -> 200* -> intercooler -> 80* -> manifold
cold air intake -> 70* -> turbo -> 170* -> intercooler -> 80* -> manifold

See what I mean?

does the turbo's efficiency change if its compressing cold air or hot air ?

And yes, assuming 100% IC efficiency that makes perfect sense. I've read on the Interweb that IC are usually 95% efficient though.

eeeerr wait. Given PV=nRT , if you took 1 liter of air at 2 psi and pulled 100 F out of it, or pulled 130 F. you'll get a larger pressure drop with the more heat you pull out of it (same number of air molecules in a given space) yes i'm using a formula for a contained space, and not flowing air , but i belive its applicable (qualitatively)

I don't believe the efficiency changes significantly with the temperature ranges we're talking about... +/- 30*F isn't really that much.

What does 95% intercooler efficiency mean? It can take out 95% of the heat the turbo put in? It can get within a certain percentage of ambient? I guess my point it, unless you've got a temp probe at the intake manifold and take before and after readings, you don't really know how well the CAI works. I'm not saying it doesn't help, but if it's only 1 or 2 degrees colder, it's probably not reducing your detonation risk at all.

For the record, I used to run a CAI and now I don't, but that's only because I switched to a BigMAF and FMIC. IMO, intakes in the fender are the way to go, simply because they get the filter element out of the dirty/crowded engine bay and into a high pressure area.

OH
yes an IC efficiency is rated by how much heat is reduced in comparison to the ambient air. so if its 80 out at Stead and your turbo adds 100 F with a 95% rate you get this .

air 80 -> Turbo 180 -> [95%] IC -> 85

Okay let's use that math:

ambient = 70* -> hot intake -> 100* -> turbo -> 200* -> 95% IC -> 76.5* -> manifold

vs.

ambient = 70* -> CAI -> 75* -> turbo -> 175* -> 95% IC -> 75.25* -> manifold

Looks like a CAI that reduces intake temps by 25* over a hot intake on a 70* day reduce intake manifold temps by 1.25*. Assuming the 100* we're picking for heat added by the turbo is realistic, but even if that number changes, the overall result still remains true: due to the intercooler, a CAI has only a very small change in actual intake manifold temps.

Exactly, so with an IC that works below 100% efficiency there would be a measurable (but small) Temp Differance in the intake manifold. 1.25 F in your example. :) Will i notice ? i bet no, but Clearly its worth the $3.50 in parts :)

it sure did bug me that on a 65ish day my filter felt over 100 though. (wild guess, maybe Nick has a better idea)

FYI i have about a 12 X 24 ish sized piece of sheet metal left over if anyone needs it for , well who knows what :)

Wait, what? 1.35* isn't going to make any difference in the performance of the motor (go ahead and try to re-tune the car for 1.25* colder intake temp)... so your $3.50 in parts is clearly worth nothing.

I'd think it would help keep the IC cooler if cooler air is entering it through the intake. IC heat soak is the real enemy.

The air from the turbo is going to be hotter than ambient no matter what, so there is no way it can "reduce heat soak", assuming you're defining heat soaked as 'the state in which the intercooler it hotter than the ambient air temperature'. Besides, the amount of air flowing through the IC from the hood scoop is *far* more than the amount of air flowing from the turbo, even at relatively low speeds.

If you want to fight heat soak, just drive the car > 10 mph, and spray down the I/C when it's stopped to get it near ambient.

CAIs are primarily about flow, not air temp on Intercooled engines. There is a great thread on this over at corner carvers. Go look for it.

And any mod <$25 and makes you feel good = 5Hp minimum, just like SECCS stickers.

Well, heatsoak usually only occurs when the car is not moving so there would be no air coming in through the scoop in that scenario. What heats up the IC? A combination of heat from the the turbo/exhaust/engine and the intake.

I surmise cooler air going through the intake on the TMIC (on a stationary car) would slow the rate at which the IC heatsoaks.

So the tempature of your charged air has NO (absolutey Zero) affect on engine performance :?: Why does nearly every turbocharged car have an intercooler then ?

Oh well, at least i only wasted $3.50 intead of the cost of a FMIC :lol:

lol double post

Here is a cool calculator for you guys to play with. The site has a metric buttload of turbo information.

Link

Steve

You surmise incorrectly. Heat increase on the inlet side does not result in a linear increase in heat on the discharge side, nor does that temperature affect intercooler heatsoak at all. The heat rising off the engine black (and blowing back from the radiator) is what does it.

Cool!

You sure you understand my post? I didn't say anthing about Heat increase on the inlet side affecting heat on the discharge side directly.

So you don't think 200*F+ air entering the IC inlet affects heatsoak on a stationary STi?

So I used Scott's example from earlier and ran it through the calculator from the link.

From the actual calculations. (Stock Boost of 11.5 psi up here)

Hot intake of 100° --> turbo --> 253° --> 95% IC --> 79° Intake Temp

CAI --> 70° --> turbo --> 215° --> 95% IC --> 77° Intake Temp

IC efficiency is more like 85% I think. I have been wanting to set up an experiment to measure temperatures on the IC for a while, maybe I'll borrow some TC equipment from work this weekend ...


Steve

Intercoolers are heat exchangers. They don't know anything about direction. they will try and make the air on the inside equal to the outside and vice a versa. So when stopped, intercooler output temp pretty much = underhood/intercooler temp since there is littel air flow besides convection on the outside.

Yes, the Intercooler will heat the intake charge.

I understand a great deal pertaining to the contents of this thread, but I simply don't have the energy or inclination to explain what I know for the 27th time on the internet. Here's the cliff notes: Cold air > warm air. Intakes that affect airflow in any way should be tuned for. Intakes that don't affect the airflow in any way are worthless.

:LOL:

You get full boost while your car is stationary? I guess that MBC really works!! :P

What if we took a big block of ice and put it on the intercooler?

Yah Dude, that's one of the benefits of running an MBC. :P

No, but I'm assuming that if your turbo is red hot from an AutoX run, the air coming out at idle is still pretty hot.

IBKevinSaysYouAssumeWrong :P

The point is that intake temp is not significantly important even at idle because it will get heated to underhood temp by the intercooler. (Some of which is caused by radient and ambient turbo heat.)

This is why we spray Intercoolers in grid. 50* water cools aluminum to <50* due to evaporation, so intercooler output temp ends up about 50*.

So why do you always make fun of me when I spray my IC? :(

I'm not peeing on my engine damnit. :P

:roll: Do you intentionally mis-read things in order to argue?

What I said was, the lower temperatures you get from your $3.50 mod makes no difference in your engine performance. IIRC, you're not even reflashed, let alone customed tuned for that whopping 1 to 5 degree lower intake temperature. :roll: So on your car, you wasted $3.50 and added useless weight to your car for no performance benefit.

On the other hand, my FMIC doesn't easily heat soak, and allows me to boost to 1.4 bar on 91 octane and put over 300 hp to the wheels... all without a cold air intake. Tell me again who's wasting their money.

How much have you put into a silly bugeye? :lol: No I kid, I kid. :P

http://www.renoscca.com/results/2006/round5_pax.txt

:P

Oh I wanna watch.

Becasue you are doing it when you are supposed to be in the car getting up to the start line. :P

And the way you hold your sprayer looks funny, so I am required by grid nazi law to harass you about it.

IF the heat of the charged air doesn't factor in, then Yes you wasted money.
If the heat of the charged air DOES factor in, then No you did not waste money (and yes of course it helps )

just drop your ego for 2 minutes
/*#include <ego.h> */
....and work through the logic. Basically if your FMIC is helping, then so is my crapper $3.50 shield. We've worked out on this thread that my lil crapper mod may be worth a ~ 1.3 F change in CHARGED AIR TEMP. and your FMIC is probably worth 100+ (i'de guess 200 but i dunno) but its the same thing (qualitatively speaking), both result in reductions in Temp of the CHARGED AIR going into the motor AFTER the IC.

either cold > hot . or it isn't :P
is 100 extra F way worse then 1.35 , Oh hell yah. its not a linear improvement , its not 100 times worse, but the first can be express as a multiple of the later. There for my shield is worth is > 0 Don't try to Quantify, just think in Binary. 0 or 1. True or false. either you want the air as cold as possible, or you don't .


printf("sarcasm\n");
okay ego back on? sure 1.5F temp change in charged air, Post IC would not make even a 1 nueton /1cm force differance. If its my car .
printf("\\sarcasm\n");

So Scott, either you were wrong when you worked out my mod could alter post charged air by 1.35 (or any number greator then 0) , or you are wrong that cold air > Hot air. take your pick :)

(i'm not saying 1F post IC makes a big differance, but i am saying given an accurate enough dyno, and the ability to hold all other variables constant, it could be measured ) in science that's called a qualitative result. its like binary its either 0 or 1. there's no indication of 'how much' it helped. I'm not claiming a Quantitive result, just a Qualitative.


And yes of course, BanSuvs is way way right about me changing the Shape of my intake. the MAF was designed to sit in a certain location, with a plastic breather box, silencer, and snorkel in front of it. if you change anything in there at all its possible to change how the air is flowing as it comes up to the MAF, and there for requires a tune.

I still think dry ice (while parked) will cool off the IC faster then ambient air. i'm sure at every ambient Temp (and humidity) one could figure out the driving speed where moving air over the IC is better then ice. (35 mph ish ? a wild guess)

and if my mod didn't help me for $3.50 worth. at least i got that much value of out this thread. i hope you did also :)

No amount of money is too much to spend for a crappy $2 trophy at the end of the year!!!

Maybe, but water is even better, much cheaper, easier to obtain, and handle than dry ice.

Water has a much larger surface contact area than dry ice, and better yet, evaporates which has an imense cooling potential.

Great Pax Results !!
You Certainaly are a Great driver, with an awesome car. the only class i'll win in a long time to come is a class of one, like STU over last weekend.

feel better ?

YOUR CAR IS NOT TUNED FOR THE MOD, THEREFORE YOU WILL NOT HAVE *ANY* BENEFIT FROM THE LOWER TEMPERATURE.

How many times does it need to be said? You can't reliably tune for the lower temp that heat shield is providing, so there is no benefit to having it. You say that the temp is lower, I agree, but it doesn't add any power to the motor unless you can up the boost/timing to make use of the reduced tendancy to detonate (not that there would be any significant difference from 2* lower intake temps), you won't see any useable performance increase. Or are you arguing that the density increase in the air from 1.3* of reduced temperature is enough to be considered a gain in performance? :lol: If that's the case, show me how much faster your car is with 0.00001 more hp from the extra 150 molecules of oxygen you're getting into the motor per combustion cycle.

As far as quantitive vs. qualitative... a change that has no quantitive benefit HAS NO BENEFIT. If you can't measure a difference in performance after a mod, then the mod did nothing. So what if the math and physics says the air at your manifold is 2* (or even 200*) colder, if the car isn't faster, what have you accomplished? Racing isn't physics class, it's about actually going faster than the next guy. I hate to sound like Vin Diesel, but if you're not faster than the next guy, it doesn't matter what crap you've bolted to the car.

wait a second. totally honest here. i really thought anystock car, no mods. would run a little better when its cold out, IE more hp. ? so every car makes the exact same HP when its 100 F compared to 32 F ?

okay sorry my bad. honestly, i thought the outside temp made a differance. :| cars are confusing :P

Of course cars make more power with cooler air, but we just calculated that the heat sheild you rigged up is only good for 1 to 2 degrees of cooler air, which when considering the variances inherrent in power output not related to air temperature, isn't enough of a temperature drop to make a useful difference versus a car without the heat shield.

Like I said, I agree that on paper you can calculate the benefit of the mod, but in real life, it's not going to do anything aside from giving you a warm fuzzy feeling that your intake is colder than it used to be.

Now, if we were talking about a normally aspirated car w/o an intercooler, this would be a totally different argument. I just don't think that the benefit on a stock STI is measurable. You're certainly not going to win a race because you added a heat shield to the intake, and that's really the only measuring stick that counts IMO.

Warm Fuzzy = +4HP... Almost as good as a SECCS sticker...

Cool. that's what i figured. that on paper one could figure out the change, but its not going to show up as a gas milage increase, more Wins, or better dyno results.

and ya its Almost as good as a SECCS Sticker. but maybe if i put a SECCS Sticker on the new heat shield ......

BTW G-Unitclothing.com is having a 30% off sale. hurry up and buy now !! you too Dean !! :P



Neee

i had no idea this thread would go this long, and in such a short amount of time.

Welcome to SECCS, where no dissenting popular internet-based opinion goes unchallenged for long.

have you seen A1337STI post before.:lol:

:lol: :lol:

What? Who in their right mind would go to the trouble of obtaining dry ice, storing & transporting it, in order to cool down an intercooler that will be hot again within a few seconds of driving the car?

If you really want your car to go faster on a track or auto-x course, concentrate on your driving, tires, chassis/suspension & brakes. An STi has plenty of power stock. The powertrain is not something to expend any effort on until you've maximized everything else.