Alright today I cut the bottom of my air box off like the Darintake mod, however I ran out of time to do all I wanted so this is a preliminary post and when I do a full write up maybe it will get moved to the DIY area.

My goal is to find the most efficient combination of DIY intake parts, this involves, the configuration of the intake/air box, the type and material of filter used and the extent of insulation that will provide a colder intake charge.

I am no stranger to DIY or homemade intakes, I hand laid a one off custom fiberglass air box for my Subaru that flowed better than any aftermarket intake.

I don't know if a custom air box is appropriate for the S4 but we'll see where we end up. The advantage to the Subaru was space, there was room in the engine compartment to route an appropriate snorkel to a fender well to obtain a source of positive pressure cold air, the S4 seems to lack this luxury. The S4 is 10 pounds of potatoes in a 5 pound sack.

I won't get into any technical discussion right now, just comment on today’s work.

My car is a 2001 stock except for an APR Bi-Pipe and a K&N panel filter.

I cut off more than the Darintake on the premise that a larger opening will flow more air, unfortunately the gains were not spectacular, I logged 3 runs stock, made the cut and logged 3 more runs after the mod (one was in English units so I had to discard it)

I made all the runs within an hour of each other, up the same grade in the same highway at the same speed with shift points at the same landmarks. Runs went from stopped to about 90-95mph, as consistent as I could get other than finding an all wheel drive dyno. The ambient air temp was within a degree for all the tests, and the altitude is about 7000 feet above sea level so keep that in mind (I am dealing with thin air)

I have posted 3 graphs, The best stock run, the best run after the mod and then a graph with all runs (the mod runs are red, the stock are blue, you can see the mod runs are consistently higher indicating a slight gain)

The data shows an increase of 2g/sec peak, not huge but a start in the correct direction, I have a lot of ideas left (even a hand laid fiberglass or welded aluminum air box are not out of the question, we'll see)

Butt dyno results: I am not sure if the car seems smoother, it might, boost seems to build slightly faster and seems that throttle response is a bit more reactive than stock, I’ll know more after my 80 mile mountain commute tomorrow.

The biggest surprise is the sound, the spooling is slightly louder but what really surprised me was the sound of the diverter valves. Yes you can actually hear the diverter valves now, pretty well in first and second before wind noise overcomes the sound. With the windows up the car is as silent as stock, some kids heard it and yelled "Nice car!" I would like to hear it from outside as the car goes by, I don't think trying to record it would work, I don't think it's loud enough.

Anyway more to come as I get the time, I would really like to take a weekend and try all the ideas I have, I want to log runs for every variation and see what combination works the best, I think it has a lot of potential.

Mason


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Nice post and nice data. It's good to see someone getting technical on here. I'm interested to hear if a fiberglass fab would work any magic.

THE FOLLOWING POST CONTAINS CALCULATIONS THAT YOU MAY OR MAY NOT UNDERSTAND OR AGREE WITH, BE FORE WARNED.

Will do however I went Aluminum sheet metal air box route just because It's cheaper and easier for me to do at the moment. This way I can make a model out of cardboard and fit it before I fab the final one up. Then all I have to do is make untape the cardboard and trace the pieces on the aluminum and then cut and weld, should be easier than the fiberglass to make the prototype.

Also I was thinking about some math and this is what I came up with, please add you input if you think my thinking is off or have any suggestions...

Before the air box mood my car was stock so lets assume it made the 250hp and 258lbs/tq (I understand that this is a factory estimate but for this calculation we'll assume it to be true, I know that the number won't all be exact but without a true dyno they never will be but this will at least give us a comparison ratio that if always calculated in this manner will tell us if we are making more power or less power and roughly how much from one mod to the next, remember don't focus on actual numbers just the ratio between them because everything is relative.)

So stock the average peak air flow through the MAF was 185 grams per second. Lets assume that the car makes peak power when there is the most air flowing into the engine (more air equals more gas equals more power) So lets say that the car was producing the 250 hp and 258lbs/tq when it was consuming 185 grams per second of air. If we divide both the Hp and Tq by the grams per second of air that should theoretically give us grams per second of air per Hp and grams per second of air per Tq. (yes I know that colder air is more dense so for the sake of this argument we will assume that the intake air temp is constant and therefore will cancel it self out of all equations, I know it isn’t realistic but we don't have a true dyno so nothing is realistic, just keep in mind this is a relative compro.)(still with me?)

250hp / 185g/sec =(approx) 1.35 (constant that means that it will take 1.35 grams per second of air to create one additional horsepower)

and

258Tq / 185g/sec = (approx) 1.39(constant that means it will take 1.39 grams per second of air to create one additional foot pound of torque)

alright so this is a base calculation for grams per second of Hp and Tq respectively. (still with me?)

so if we gained 2.75 grams per second of air from the hole I cut in the air box we can calculate the theoretical gain in Hp and Tq. All we have to do is multiply the constants by the increase in air flow:

1.35 (our constant for Hp) * 2.75 (grams per second of air increase that we can attribute to the hole I cut in the air box) = 3.71 Hp

now torque:

1.39 (our constant for Tq) * 2.75 (grams per second of air increase that we can attribute to the hole I cut in the air box) = 3.82 foot pounds of Tq

So the hole in the air box did create a definite gain although at this point we can only speculate as to how much, should be interesting to compare once I try a cone filter and try and increase air flow to the air box as well as eventually (if it is feasible) fabricating an aluminum air box that should be superior to the stock one.

I would appreciate comments, questions, flames or any other input you may have, also has anyone measured or know of anyone who has measured stock air flow through the MAF? Are my numbers close to others? How much more is the air flow if you are chipped? Other mods that have effected the air flow (keep in mind that just like a Dyno results will vary but it is interesting to compare anyway.)

Mason

I follow you, and it seems theoretically sound, but not sure about practical application. It's early, let me think on this some more.

umm kinda right
"258Tq / 185g/sec = (approx) 1.39(constant that means it will take 1.39 grams per second of air to create one additional foot pound of torque)

alright so this is a base calculation for grams per second of Hp and Tq respectively. (still with me?)

so if we gained 2.75 grams per second of air from the hole I cut in the air box we can calculate the theoretical gain in Hp and Tq. All we have to do is multiply the constants by the increase in air flow:

1.35 (our constant for Hp) * 2.75 (grams per second of air increase that we can attribute to the hole I cut in the air box) = 3.71 Hp

now torque:

1.39 (our constant for Tq) * 2.75 (grams per second of air increase that we can attribute to the hole I cut in the air box) = 3.82 foot pounds of Tq"

If every 1.35 grams equals roughly 1 more hp why are you multiplying it by 2.75?????

you need to DIVIDE 2.75 by 1.35 which equals 2.037......you gained 2.037 hp not 3.71

lets say you make the hole alot bigger say 3.5 times bigger okay with your method of multiplying heres how it would go 1.35 x 9.626=12.993

with my method itd be 9.626/1.35=7.129

just take what you have more of grams of air and divide by the constant to get the increase





i could be drunk though........good chance

Just a little FYI on making graphs.

Use the X/Y chart and put RPM or time on the bottom. It makes it much easier to read & understand.

http://img.photobucket.com/albums/v654/DocSlow/HomebrewStage367F8-24-06MAF.gif

Back to the intake....
Where did you cut the holes? How much did you cut?
The bad part is if you take to much, it will disrupt airflow, and can cut flow.
If the holes are in the wrong place, they can suck in hot air, also decreasing flow.

The Darintake has proven over & over to flow about 20g more then the stock airbox.
Of course when you upgrade the car the flow will change.

The on design that seams to work best on modded S4's in the Racer X-1 intake.

http://images15.fotki.com/v337/photos/4/43687/3825505/20060724YPipe018a-vi.jpg

Alright if every 1.35 grams per second is approx 1 hp and every 1.39 grams per second is approx one foot pound of torque, why would I divide the increase in airflow? I want to know how many hp and Tq respectively each "new" gram per second of air gained. So I would multiply each new gram per second of air by how much each gram per second of air contributes to Hp and Tq respectively....(does everyone agree that that is the correct method of calculating the ratio of grams per second of air to how much Hp and Tq is produced(not that it is accurate but that the math is correct in guestimating a ratio between the two))

and Yes i have looked at aftermarket intakes, and yes I do feel that they are over priced and I do believe that the Darintake did net something like 20 g/sec but I believe his car was chipped, my car is stock, and like i said this is the first out of many ideas.

here is my thoughts on the stock intake.... more math so hold on....

I am not sure if altitude is a factor, I will try and call Mike at Pure and see what the standard code is to activate a program.

as for the intake, I am not sure how much it can be improved if the car is stock. The biggest thing I have a problem with is looking at the relatively tiny snorkel that runs from the grill to the air box. Both my S2000 and Subaru had some form of after market intake, the S2000 was 3" in diameter and the Subaru's was 4" in diameter. if you calculate the cross sectional area (Pi *r*r) or Pi times radius squared the 3" would have an area of 1.5* 3.14 = 7.06 now this is not a flow rate but is the maximum area that ALL of the intake air must flow through in order to enter the combustion chamber of the engine. The S2000 also redlined at 9000 rpms so you can imagine the velocity at which the air must be flowing through the intake in order to fill the combustion chamber 4500 times in a minute(a four stroke engine has a combustion cycle which is 3600 degrees and an exhaust cycle which is also 360 degrees, which means that it fires only every two revolutions.) The Subaru on the other hand had a 4" intake so we calculate 2*2*3.14 = 12.56 that's 5.5 more square inches of cross sectional area that intake air can occupy. That is a 78% increase in cross sectional area over a 3" diameter intake. Now again this is not flow rate, but that means that the given air that will be sucked into the intake by the engine has 78% more area to occupy. We can compare this to a hu8man trying to suck a given volume of liquid say a can of soda through a tiny straw or through a garden hose. It is going to be much much easier to such the soda through the garden hose and much more efficient as well, which means it will take less time to suck the can of soda using the garden hose. I look at the stock snorkel on the S4 and it seems smaller than a 3" intake. I am not sure of the exact measurements but it seems like it is the choking point of the stock intake system. One final point I would like to emphasize is that the S2000 and Subaru were both N/A which means that they had to basically suck all their air into the intake from the negative pressure created by the down stroke of each piston. The S4 id Bi Turbo which means the turbos compress air in the intake(after the air passes through the compressor housing on the turbo of course) and the air is actually being forced or pushed into the combustion chamber. This means that there is more air being consumed by the S4's engine than a natural aspirated car and that all of that air must flow through the relatively small snorkel that goes to the stock air box. This in my mind means that eliminating restrictions such as the snorkel are even more important on this car because of the increased air flow that the turbos present.

Again please let me know if my logic is flawed or if you have any other comments or questions...

Mason

2k S4....

this is the only problem I have with that intake, it doesn't address my biggest concern, this seems like the absolute choke point for the stock system and this aftermarket system: notice that this intake also relys on the the reletively small opening in the grill to flow ALL of the air that will enter the combustion chamber..... (notice the red circle)

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First off, you can't count airflow & correlate it to direct HP. It takes more then air to get HP.
You have to take into account fuel, ignition timing, valve timing, boost, etc...

The stock small snorkel flows a lot more then you think, it's placed in a low pressure area.
There are a lot of high HP K04 cars running with the stock airbox, or the RS4 one.

The X1 intake is also open behind the headlight. In test has proved to have some of the highest
flow. But most people using it are heavily modded, and have a much bigger MAF.

Most tuners seam to like the stock or RS4 airbox. The consensus is unless you have K04's
there really isn't much to be gained on the intake. The RS4 box has a flapper in the side
that opens under WOT, just think darintake, with a rubber flapper.

Forgot to add...
When doing CFM with car intakes, you have also account for the air pressure around the part.
That can add or reduce flow. There are other factors as well. Really while doing the math is nice
it only tells part of the story, you really have to test each application on the car & do logging to
see what the best compromise is.

One last thing, don't forget the MAF likes nice smooth airflow. Some times putting to much high
turbulent pressure at the MAF will make the car run worse performance wise.

wow - kudos to you socal - and great input here as well 2k. I'm no auto techi myself (pure driver here!)..so admittedly I just skip the numbers part and try to pick up on the jist of what your getting at - and I think this is an area where we might get some gains with our cars. (having no stock airbox when I purchased the car used) I went with an open element EVO and have been fairly pleased with the performance (and engine bay sounds!) - but the very hot engine and limited air entry to the filter/MAF do concern me and leave me wondering if I could get noticable performance gains from just getting more/cooler air. I really like that cf heatsheild with the X-1 intake - is that fitable to my EVO intake ya'think? I've also wondered how one might get more cool air into their in general and am glad to see the likes of socal expireamenting in this area. Any chance of some pics?

I know I know I know

I appreciate your input and understand how flawed my data and calculations may be, but frankly it's the best I can do with the resources available to me.

Not sure exactly how much you read, I said many times that this is not sufficient to calculate Hp and Tq only that if I always use the same formulas I can compare the data from each different modification and see if there is a net gain or loss. Audi has spent tons and tons of money on the engineering of their products, I will never be able to compete with them or any after market intake company, I do this because I ENJOY it, not to make money or re invent the wheel so to speak. I am looking at 40k in student loans so if I can gain a few Hp for free or relatively cheap then I will take them.

I understand the concept of turbulence I attended Cal Poly Pomona and attended the State Science Fair three years, one year with a full size working wind tunnel. No matter if the intake is stock, RS4, Aftermarket or home made the concept is the same:

The more air the more fuel the more power. How you deliver the air to the combustion chamber is also important, if the air flow is smooth and less turbulent then it is more efficient which means delivering more air in less time. There is an absolute amount of air the engine will draw even if the intake is completely unrestricted, this means that it can only suck so much, the key is to make whatever intake you have installed on the car get as close to this point as possible while still sufficiently filtering the air as to not increase wear on the engine from dirty air. Ideally we would want the coldest, most dense, least turbulent air flow possible. However, this is impossible due to the fact the 1. the engine will always create heat and that heat will always heat the incoming air. 2. as air increases in temperature it becomes more excited and less dense (intercoolers help cool the air after compression by the turbos) and 3. the air box is inside the engine compartment creates poor air flow characteristics due to the fact the the air has to basically navigate a maze from the atmosphere to the combustion chamber, there will always be turbulence, and unfortunately there is not a whole lot of room in the engine compartment to minimize the path of the intake air (for example if the headlight was removed from the the passenger side I am sure a HUGE gain would be accomplished but other than a drag strip or track day that is just not plausible)

keep the comments and thoughts coming, two brains are better than one and all of us are better than just me...


Mason

yeah when I pull the stock box I'll make sure to photodocument the progress... and I am not sure how effective the carbon fiber is against the radiated heat, I mean I am sure there is some advantage, however I am leaning towards a true insulated air box, it's won't be as pretty but should be more effective...

ORIGINAL: socals4driver

yeah when I pull the stock box I'll make sure to photodocument the progress... and I am not sure how effective the carbon fiber is against the radiated heat, I mean I am sure there is some advantage, however I am leaning towards a true insulated air box, it's won't be as pretty but should be more effective...


Looking foreward to you reporting your results. Yeah - there is boku heat under that hood...and a cf shell will likely only block out so much...

I know where your coming from.

So you are looking for the lowest cost, highest performance intake (aren't we all?).

Most of the time we can improve on the Audi engineers. Most of what they do is a compromise between, cost, performance, sound, comfort, etc...
I know I will give up some noise level, comfort, for more performance.

Here is what you need to do.....

Remove the entire airbox, & filter, go 7 do some logs, this the MAX air the engine will flow threw it, unless you change something else.
Driving a few miles with no airfilter is fine. So log grams, and temp. Also once you stop, use a IR Thermometer on the intake hose.

That will become your base. Then when you try other setups you have the baseline to compare.

My main point is the airbox setup is NOT the bottle neck in the system. You will get more gains by changing the exhaust, or cleaning up the intake
track, sealing every little leak. The best performance mod is a well maintained engine, I always start there.

Even with the X-1 intake people with out K04's do not see any real gains over a stock airbox with a panel filter.

Since were talking about degree's I have a BS in Physics.

I ran the car with no box or filter a few days ago when i posted my results, there was really no differece from stock to nothing i would assume that this is due to the turbulence factor you mentioned earlier, and the fact that the MAF was sucking nothing but hot air from the engine compartment.

I do have an IR thermometer and thought of that but the data loggin software does display the intake temperature of the air as it is entering the throttle body, and that is ultimately where we want the air to be cooler, so i am not sure if i will mess with the IR thermo and the temp, it will simply be another variable in our already flawed equation, plus there is so so much radiated heat from the engine i doubt it would change much (the important part is to get the air entering to e colder and more dense and in my opinion the IR thermometer is not an accurate enough method to justify the trouble.)

Interesting 2k S4...well my car is very well maintained I think and right now - except for an intermittent brief engine cut off issue around 4k rpm (that does not ussually occur often) I think the car is running great - no leaks - etc. And I'm pretty happy with my AWE setup in regards to flow under hard throttle...I am running stock intercoolers and have considered upgrading - but results posted on other forums leave me wondering concerning the potential for gains...and its not so much the flow into the MAF IMO - but the heat of the engine and of the air the engine is heating up going into the filter. BTW when I bought the car it hat this HKS hemisppherical foam filter that looked really cool - but did not filter very well - might as well have been running no filter at all...I went with the EVO open filter setup because I had heard good things about it and liked the look and because I had no stock airbox. We considered an RS4 airbox...but I was more concerned with the engine heat then restricted airflow or such - thus the apeal of that X-1 setup...though not sure if it is really all that much beatter then the very minimal attempt at isolation that came with my EVO setup...

i think that the most overlooked part of the aftermarket intakes is the attempt or lack there of to insulate the intake from the heat of the engine, i single layer of Carbonfiber is not going to do much in the way of insulating, also I found on my car there is really no heat shield between the passenger side header and the stock airbox, this to me seems rediculous.

I fabbed up a cardboard version of what i will attempt to construct out of aluminum tomorrow, I also got the largest cone filter i could find, I was dissappointed when i was looking for other places to induct cold air into the airbox, the best location is the top of the fender, but i am concerned about sucking up water, I will make my intake with an option to open or close the bottom to the fender well, basically the ability to have a darintake style hole or no hole. I also saw potential for a fender gap behind the passengerside corner light, but i doubt that much air will make it past the intercooler ducting and up the fender to the small hole, but it's worth a try i can always cover the opening in my box later if it seems not to be beneficial.

Hopefully pics and Vag Com runs tomorrow...

Mason

The concern about sucking in water is a real one. Before my recent mods I twice had to replace my MAF after doing just that. Sucked up lots of dirt into the engine as well! I'm just lucky that both these instances didn't cause more damage. I was using the HKS mesh filter at the time - and it didn't stop much of anything from comming through...a filter in name alone (but the performacne aspect of the intake was quite good...lol)...except of course for the heat concern...were a bit f'd in that regard i think....but anxiously awaiting any reports of sucess that you might have!

I had an epiphany tonight, tomorrow should bring some interesting results...

Mason

ORIGINAL: socals4driver

I had an epiphany tonight, tomorrow should bring some interesting results...

Mason



I hope so ! cant wait to see how it goes...
I know the general consensus is the stock airbox is best.
until you go into the stage 3 realm... but if there is a cheap / better alternative,
I'm all for it.



maybe thats why carbonio never came out w/ an intake for our application? ;)

If you do the no filter thing again, try putting a short section of tubing on the end. This would be a
ghetto velocity stack. It will smooth out the airflow quite a bit.

Yes, there is no real good place for the air filter. The S4 engine bay is WAY, WAY to hot. Honestly I'm thinking about
the ricer vented hood, to help with airflow. I'm also very upset that our cars don't have a stock oil cooler!

You should take temps of the intake & Y pipe when you are done. The better the cold air flow the lower the intake temp.
It may be slight due to heat soak, but a good cool intake will lower the temps. It also good to know if a higher flow
intake is pulling in more hot air. I know from past experiences that some cone filters can get heat soaked, and just
suck after they get hot.

Anyway, back on topic. The best place for cool air seams to be behind the headlight. Don't worry about rain getting
into the filter, some is ok, and if the filter is placed back it should be fine. If you are really concerned, put a cheap
foam panel filter right behind the headlamp. So it will prefilter, and pull water away from the cone filter.

CF is really good as a heat shield. It has a very low absorption rate, and dissipates quite quickly. The CF, fibers
have a very high surface area per sqin. So far the X1 intake shows the lowest intake temps.

Another thing you can do is put a heat shield on the accordion hose & Y pipe, that will really help lower temps.
Another Ghetto mod, take some ALM Foil and cover them up, then go & do your measurements. This will also
help with measuring intake temps as it will give you a more true reading.

I just picked up a used AWE S-flow & will be putting it in today, I don't expect much over my ITG panel, but we will
see.

I will stand by my guns & say that the stock airbox & panel filter or cone in the airbox, with the Darintake is the BEST for a K03 car!

RESULTS!!!

Alright I will sum it up in list for you impatient people, then explain the results and my thoughts on them afterwards.

1. I increased airflow through the MAF an average of: 8% increase over stock and 3% increase over the Darintake.

2. I decreased the temperature of the air at the THROTTLE BODY by an average of: 34 degrees F less than stock and 30 degrees F less than the Darintake.

3. I separated the COLD air for the intake and the HOT air from the engine as much as possible, creating a difference of 62 degrees from the engine to the filter element. (this means the filter element was 72 degrees F and the engine was 140 degrees F, so the engine was getting air that was 62 degrees F cooler than if it was sucking in hot engine air.)

4. I spent a total of about 70 dollars not including my labor, but aftermarket intakes take time to install as well, so I cancelled out the install time.

5. I enjoyed doing something that benefits my car's performance, my knowledge and understanding of how my car works and the concepts involved.

6. I created something that no one else has ever created (kind of, the principals are the same, but I have yet to see a welded aluminum insulated intake compartment, at least not on a B5 S4.)

7. We all gained valuable knowledge concerning the intake of the B5 S4.

Okay so here comes the technical part and my ideas on why everything turned out the way it did.

Before we go down the list let's examine my thinking regarding the intake.

Yesterday I fabricated a new larger air box from cardboard with the thought that the bigger I can make it the more air that it will flow. After looking at how tight it fit and seeing the complete lack of airflow(besides the stock snorkel) I decided to stop and think and examine if it was the best idea for this application. Three problems kept bugging me all different variables of the intake.
1. The B5 S4 just has too much in the engine compartment. (10lbs of potatoes in a 5lb sack)
2. The stock snorkel was deemed adequate by the Audi engineers (though to me it seems tiny)
3. There is ZERO attempt to heat shield the air box/intake system from engine heat.

After think about these three things I came to the conclusion that I could only really change one variable. Since I cannot remove anything from the engine bay (the passenger headlight springs to mind first) and there is no feasible way to really gain any substantial amount of airflow to the MAF (cold air is almost impossible to introduce besides the stock snorkel or putting in a hood scoop) I realized that my best plan of attack was to combat the heat since it was the only variable I could change and since the issue had not been addressed by Audi at all which is kind of strange (the air box and filter sit less than an inch from uncovered headers on the passenger side of the engine.)

So last night I re-strategize and I decided I would not make a new air box but more of a dam to separate hot air on the engine side from cold air on the intake side. I constructed the dam from .125" aluminum plate, with a layer of foam/aluminum pipe wrap insulation on each side. I then riveted on a piece of .020" aluminum sheet over the insulation to make sure it didn't come off when the temperatures rose. The dam is essentially three piece of this triple thick insulated aluminum. The aluminum dam runs from the frame rail that is under the stock air box all the way to the hood where a gasket made of rubber garage door gasket seals to the bottom of the hood like the stock gasket that seals the perimeter of the hood. That is the basic design, very simple, one goal in mind separate hot engine air from cold intake air.

Alright lets discuss results.

1. I increased airflow through the MAF an average of: 8% increase over stock and 3% increase over the Darintake.
The first graph shows the average air flow (grams/second) of three runs for the stock air box (red) two runs done with the Darintake (green) and 4 runs with the Masontake (blue).
The highest readings were:
Stock Air box: 185 grams/sec
Darintake: 187 grams/sec
Masontake: 192 grams/sec

The first graph shows the average of the three highest recordings for each run which shows that the Darintake flows consistently more than stock and the Masontake flow consistently more than stock and the Darintake. It should be noted that the small scoop I placed in front of the snorkel entrance has not been proven to increase air flow, I have not had time to test the Masontake without the small scoop(called the grill scoop) so I cannot claim that it adds to the increased airflow, more testing to come in the future.


2. I decreased the temperature of the air at the THROTTLE BODY by an average of: 34 degrees F less than stock and 30 degrees F less than the Darintake.
(all runs were done under the same conditions, same road, same ambient air temperature, same relative humidity)
The Second graph shows the average air intake temperatures.
The Vag Com reads the air temperature at the junction of the Bi-Pipe just before it enters the Throttle Body, introducing the coldest air possible to the intake will lower air temperatures throughout the entire intake system (filter element all the way to combustion chamber) Since I have no reliable way to measure the temperature of the air as it enters the filter we must rely on the Vag Com to tell us the air temp at the throttle body. A 34 degree F drop in temp at the throttle body means a substantial drop in temp at the filter. I have an idea to measure the air in the air box and will post more later. I knew the insulation and separation of hot engine air and cold intake air would have a positive effect but I had no idea it would cause this much of a change.

3. I separated the COLD air for the intake and the HOT air from the engine as much as possible, creating a difference of 62 degrees from the engine to the filter element. (this means the filter element was 72 degrees F and the engine was 140 degrees F, so the engine was getting air that was 62 degrees F cooler than if it was sucking in hot engine air.)

I used my Infrared Thermometer several times to measure the temperature differences on different parts of the intake and engine. I found that the air dam that I created was very effective. I think the thickness of the insulation is the key, also the bare aluminum on the engine side helps reflect as much heat as possible. Overall I am very pleased with the thermal insulating efficiency of my design. The stock air box used to be hot to the touch, my cone filter and the intake side of the air dam is cold to the touch.

4. I spent a total of about 70 dollars not including my labor, but aftermarket intakes take time to install as well, so I cancelled out the install time.

Granted I did have all the necessary tools and a lot of the materials but I priced the aluminum as it could be purchased at any Lowes or Home Depot. No matter how you look at it, this is much much cheaper than an aftermarket intake. And yes it looks way more ghetto too, but if I spent 400 dollars I am sure I could make it pretty.

Things to come....

Heat shield for MAF (this to me is the next must do as the MAF was almost 100 degrees F more than the intake and filter element. it needs to be shielded from the heat of the engine because it sits above the passenger side turbo and exhaust.)

Better filter?

Thermometer for inside air box area?

Insulate the Y pipe and Bi-Pipe?

Vag Com without Grill Scoop and or redesign grill scoop

Vag Com without passenger headlight

Like always any questions, comments, complaints, rants, flames, whatever is appreciated.

Mason


HAHAHHAAH I forgot to link to the pictures: MASONTAKE PICTURES (http://mperry9.photosite.com/AudiS4IntakePictures/)

local://upfiles/8989/ED497C3ED2434601B37595210F23B0C7.jpg

local://upfiles/8989/412DF813CB26414B8ECFC7B37566329F.jpg

I felt that these three were important enough to be posted here

these were taken with my IR thermometer after several different runs, all readings were within a few degrees from one run to the next (ambient air temp was 72 degrees F)

this is why my next mod will be insulating the MAF and the black plastic accordian section directly after the MAF ( they both read from 170-180 degrees F)

local://upfiles/8989/46BFE640C41447B9BBFA91110CC52132.jpg

local://upfiles/8989/58D82E02B77743F789E4EFA02946E289.jpg

local://upfiles/8989/62457F335DC94E0B8123C06B7FECBB84.jpg

ummmm lets say a 2gram increase in airflow equals 4hp (it doesnt these are juist easy numbers:))

anyway if you wanna find out how much more hp your going to get out of an increase of 12grams of air you would take 12/2 = 6 sets (2gram in each "set") every 2 gram set equals 4hp so youd multiply 4hp by x amount of sets which in this case is 6 sets so 4x6 = 24hp incease

now lets apply this correct method to what you said you said 1.35 gram increase of air flow equals ~1hp ....therefor youve touve increased your airflow by 2.75 grams it is only logical to divide that into packets of 1.35 grams....once divided it is now 2.037037 packets...okay now multiply the # of packets by the hp increase of one packet(1hp increase) 2.037037 equals 2.037037 increase of hp

that is the correct way to do it i am not drunk......woot!!!!

correct i would agree that there was NOT a 24 hp increase. I am curious to know how dropping the temperature effects the air density and how in turn that effects hp.

Take some better pics! There way to dark to see what's going on, all I see is a big cone filter[:@]

Very well done, it seams like it's working for you. Lowering intake temps is just like getting more cfm.
The cooler the air, the more dense, the more HP it makes per volume.
So at 200g/s @ 100deg will be more dense & have more volume giving more HP per g/s over
225g/s @ 200deg.

It's also eaiser on the turbo's, they will spool faster & work less creating less thermal transfer
to the intake charge air. This will also add HP, and make the IC work more efficiently.

On a turbo car, cooler air helps every where!

Now what you have to do is some FATS runs, or head to a Dyno to see if there is fact a HP increase.
Believe it or not, more airflow, doesn't always mean more HP @ the wheels.

Well done!

I know the pics were taken at dusk, so I will have to get some better ones soon, and yes I agree that more airflow doesn't me more hp, I think the cone filter I have in there now is turbulent, and am planning to try something else maybe an S-flo.

I am going to be doing some runs coming up, I think I may just devote a whole day to compairing the stock airbox with the Darintake mod to what I have set up now and then maybe trying several different filters. I do want to do it down the hill though as I am at 7000 feet and would be curious to see if there is any difference at elevations closeer to sea level.

I will also be insulating the throttle body and correcgated hose that follows it in the near future as well.

Mason

ORIGINAL: vnv727

ummmm lets say a 2gram increase in airflow equals 4hp (it doesnt these are juist easy numbers:))

anyway if you wanna find out how much more hp your going to get out of an increase of 12grams of air you would take 12/2 = 6 sets (2gram in each "set") every 2 gram set equals 4hp so youd multiply 4hp by x amount of sets which in this case is 6 sets so 4x6 = 24hp incease

now lets apply this correct method to what you said you said 1.35 gram increase of air flow equals ~1hp ....therefor youve touve increased your airflow by 2.75 grams it is only logical to divide that into packets of 1.35 grams....once divided it is now 2.037037 packets...okay now multiply the # of packets by the hp increase of one packet(1hp increase) 2.037037 equals 2.037037 increase of hp



umm i didnt say there was in your case it was simple math to point out your mathematical error....it WAS a 2.037037 increase of hp assuming the assumption which this question is based on is true...ie 1.35 gram increase equals a 1hp increase

ORIGINAL: socals4driver

THE FOLLOWING POST CONTAINS CALCULATIONS THAT YOU MAY OR MAY NOT UNDERSTAND OR AGREE WITH, BE FORE WARNED.

so if we gained 2.75 grams per second of air from the hole I cut in the air box we can calculate the theoretical gain in Hp and Tq. All we have to do is multiply the constants by the increase in air flow:





no no no...you have to didvide 2.75 by 1.35 and you get 2.03037 hp increase