Custom intake

[Fociracr]

So I decided to make my own custom intake for my S4. I couldn't justify spending $200+ on a tube with a filter. I don't really care for any crazy HP gains (HP gains are negligible with intakes) anyways, I just wanted to hear the supercharger whine more. Well I added a pic so you guys can see what it looks like. It cost me roughly $50 to make give or take, so for a quarter of the price I'm ok with it. I know people are going to bitch about how I could do this to a $50k car but I like it. Let me know what you guys think. I'm still a noob to uploading pics to forums so you'll have to copy and paste the link.


http://s1108.photobucket.com/user/Fo...7.jpg.html?o=0

[DGVR6]

I think it looks fine. Sucking in hot air but I'm sure you don't care about that.

Edit: Id watch that fuel line or wrap it to protect it from that pipe.

[Fociracr]

Thanks bud. Well I initially installed the cover and it was very quiet so I put a few holes in it. I have a multi meter that measures the temperature of the ambient air with a wired probe. I ran that probe to the actual box before and after I drilled the holes and the temp when driving is exactly the same, it only gets slightly hotter when sitting. As for the fuel line I'm planning on maybe wrapping the intake with some sort of exhaust wrap but I'm sure it'll do more bad than good. I'll have to find a clip and simply clip it to it. like the stock one.

[AZT]

Well I initially installed the cover and it was very quiet so I put a few holes in it.

A few holes, you mean like 22? :) Kudos to you for coming up with your own ideas. So how's the sound/whine now?

[Fociracr]

HaHa well I started off with a handful but ended up with "22", the sound is fantastic not as loud as with the cover completely off but loud enough to echo when going under a bridge, its not cobra terminator loud but loud enough. I might make another cover without holes for the winter just in case.

[Oloung1]

details on the cover? mounting points, how you made the joints, how many sides are closed, if you decide to box the filter in if it isnt already?

[torinalth]

not bad honestly. I agree about wrapping the rubber hose, and make sure there is no contact on the metal pipe (AC line maybe?) underneath. I don't care for shiny though under the hood, so I'd personally paint it a matte black but that aside, I'd just enjoy

[fitzydude]

Looks great! I wish I would have gone this route! Someone should find a Honda kit on eBay that has perfect size tube for our car.

[jran76]

What filter and pipe size are you using? I would definitely log IAT's, air mass, and air pressure to see what it is really doing if you care about its performance beyond the increased sound. In general, the best performing intakes I've tested do a good job at blocking heat with a heat shield between the engine/exhaust manifold and intake, and then run the largest filter possible (without the restrictions of the stock airbox). The stock filter size itself is OK.

There is a little more to most of the intakes available than a pipe and filter. Most come with a breather hose adapter, some form of the aforementioned heat shield, and an intake pipe with a 3.5" opening on the filter side and 3" opening on the TB side to allow for use of the largest possible filter while maintaining smooth airflow. The shape of the intake pipe makes it hard to use a generic pipe for this purpose, and still safely clear the coolant and fuel lines.

[Fociracr]

Well here's a couple of details if people are interested. The intake tube is 3". All it is is a intake tube for a completely different vehicle (dodge Durango I can give more info if people want to replicated) but it actually works really well. The filter is just a generic filter that came w/ it with a 3" opening. I left the stock air box in place till I figure out how to block of the whole section off all together so I can remove the stock box. so basically I removed the top cover and ran the pipe to the stock box with the filter mounted to the pipe (like the injen style intake). The cover itself is made out of aluminum sheet metal. I traced the stock air box cover onto the sheet metal and cut it out. I sanded the edges and made them nice and smooth and removed all the burrs so that I don't inadvertently introduce any metal into my engine. I'm and airplane mechanic so I have access to air tools and a plethora of metal. Once I cut it out and drilled the holes in the top I wrapped it with vinyl wrap. I also utilized the stock air box cover screws and screw holes to fasten the cover down. I'd be more than willing to run some logs I have a vag com but I'm not too familiar on how to run logs so if someone wants to school me on it I'd be more than willing. I'll take some more pics tomorrow.

[Fociracr]

Almost forgot I drove it the other night and let it sit for awhile. I touched the intake tube and it was very hot to the touch (heat soaking under the closed hood) which I'm sure they all do, so I decided to take it for a spin to see if the temp would increase or dropped, well to my surprise I popped the hood and touched the tube and it was as cold as the ambient air outside.

[jran76]

Well here's a couple of details if people are interested. The intake tube is 3". All it is is a intake tube for a completely different vehicle (dodge Durango I can give more info if people want to replicated) but it actually works really well. The filter is just a generic filter that came w/ it with a 3" opening. I left the stock air box in place till I figure out how to block of the whole section off all together so I can remove the stock box. so basically I removed the top cover and ran the pipe to the stock box with the filter mounted to the pipe (like the injen style intake). The cover itself is made out of aluminum sheet metal. I traced the stock air box cover onto the sheet metal and cut it out. I sanded the edges and made them nice and smooth and removed all the burrs so that I don't inadvertently introduce any metal into my engine. I'm and airplane mechanic so I have access to air tools and a plethora of metal. Once I cut it out and drilled the holes in the top I wrapped it with vinyl wrap. I also utilized the stock air box cover screws and screw holes to fasten the cover down. I'd be more than willing to run some logs I have a vag com but I'm not too familiar on how to run logs so if someone wants to school me on it I'd be more than willing. I'll take some more pics tomorrow.

Here is my thread on logging. Let me know if you have any questions. Obviously, it would be best to get a before and after, but it sounds like you could switch back pretty easily.

http://www.audizine.com/forum/showth...rmance-Logging

[Fociracr]

Tx I'll update soon I hope.

[Fociracr]

hey i got some logs but they're quite lengthy i doubt i could copy and paste them here so let me know what way you'd like me to upload them. I used your guide to logging and i noticed something strange, on my #5 cylinder once the temp starts rising and i start getting on the throttle the timing pull maxed out at one point at -7.125 my car is stock and it was a cooler night 61 degrees F with humidity. So im not sure why its pulling so much timing. But anyways let me know how you'd like me to upload the logs.

[jran76]

hey i got some logs but they're quite lengthy i doubt i could copy and paste them here so let me know what way you'd like me to upload them. I used your guide to logging and i noticed something strange, on my #5 cylinder once the temp starts rising and i start getting on the throttle the timing pull maxed out at one point at -7.125 my car is stock and it was a cooler night 61 degrees F with humidity. So im not sure why its pulling so much timing. But anyways let me know how you'd like me to upload the logs.

You can post them to a google drive or Dropbox account if you have one. It's not completely uncommon to see 6-7 degrees of timing pull from time to time. It doesn't sound like the conditions, but maybe gas or other factors. I'll take a look at the logs if you can post them. If you want to email them to me, shot me a PM. Also, let me know what type of gas you are running and elevation if you can.

[Dudemans4]

I bought an intake tube and k&n cone filter from advance auto parts. It fits perfect I trimmed the end to shorten the pipe about an inch but overall it looks like it's supposed to be that way

[pdqgp]

Kudos for taking it on but the hot air intake part is a negative IMO. Will be interested in seeing your logs from a stoplight as the car takes in a huge breath of hot engine heat.

[AZT]

Kudos for taking it on but the hot air intake part is a negative IMO. Will be interested in seeing your logs from a stoplight as the car takes in a huge breath of hot engine heat.

I suspect it may not make that much difference. IATs heat up quickly at a stoplight even with the stock intake. The stock snorkel has little underhood holes facing up too. Besides, just take a look at how Audi themselves modified the 4.0TFSI airbox for the RS6/7 - look familiar? :-) The same airbox in the S versions of the 4.0TFSI does not have those holes.

[DGVR6]

It would make sense if those were there as vents. OP could be on to something.

[jran76]

I suspect it may not make that much difference. IATs heat up quickly at a stoplight even with the stock intake. The stock snorkel has little underhood holes facing up too. Besides, just take a look at how Audi themselves modified the 4.0TFSI airbox for the RS6/7 - look familiar? :-) The same airbox in the S versions of the 4.0TFSI does not have those holes.

It would make sense if those were there as vents. OP could be on to something.

It definitely makes a difference in IAT's, but probably doesn't impact performance too much in the long run. I just wouldn't go into it thinking you're gaining any power. I went back and looked at my logs with and without the snorkel (same effect as the holes basically), and you see something around a 5C increase in IAT's when breathing engine air. With that said, you're right, IAT's go up very quickly regardless, and this platform is particularly susceptible to timing pull as IAT's increase. At the end of the day, maybe you're talking 1-2% one way or the other. That may be a worthwhile sacrifice if you are after more sound.

The RS6/7 shown has the manifolds/turbos in the V bank of the engine, and the engine cover has quite a bit of insulation on it. Those holes are pretty far away from the main heat source in the engine bay on the S6/S7. The manifold (albeit, not as hot) on the 3.0 TFSI is directly next to the air intake.

If there is a real sacrifice with this particular setup, it is the 3" pipe. The stock filter has a much larger opening (over 3.5"), and all the high performing aftermarket intakes go from 3.5" at the filter to the 3" TB. I'd like to see what both IAT's and air flow/pressure look like stock and with this intake before making any conclusion....

[pdqgp]

[QUOTE=AZT;10994649]I suspect it may not make that much difference. IATs heat up quickly at a stoplight even with the stock intake. The stock snorkel has little underhood holes facing up too. Besides, just take a look at how Audi themselves modified the 4.0TFSI airbox for the RS6/7 - look familiar? :-) The same airbox in the S versions of the 4.0TFSI does not have those holes.



Ironically the aftermarket for the RS7's also fully enclose the intake to insure Cold Air Flows in. Check out AWE's version. Pretty nicely done. We can debate it all you want, if you're fine with your car sucking hot air from under the hood that's fine. The better design is to pull colder ambient air from outside. Not just from a stand still but while rolling too.

Been there done that debate even way back to the mid 90's on GM's L68 SC 3800's in the Buicks and Pontiacs. Lots of people would cheap out and simply slap a K&N Cone filter on the intake and it was proven many times over the sucking of that hot air didn't help outside making more noise.

[bhvrdr]

The stock filter has a much larger opening (over 3.5"), and all the high performing aftermarket intakes go from 3.5" at the filter to the 3" TB. I'd like to see what both IAT's and air flow/pressure look like stock and with this intake before making any conclusion....

Its true and I agree but just to point out that the popular roc euro/ CTS is still basically the same 3" tube that just flares out to a 3.5" filter for the last 1" of the tube. That is really the only difference in actual tube design. It may make all the difference. I'm not sure. I agree it'd be interesting to just try a 3.5" tube and filter too. It would actually be at least as big as most of the current options. Wouldnt be any harder to source i'd imagine. Anyways thanks for sharing OP. Be cool to see your ongoing results and see if you continue to develop this.

Mike

[AZT]

Could go with a 3.5" pipe and then use a 3.5" to 3" silicon reducer at the TB.


Not sure how much it really matters to have the airway between filter and TB to be any larger than TB. Perhaps the transition is most important (that it is a gradual/venturi transition to the TB diameter and not abrupt). And ironically, APR's intake tube in the middle necks down to even a little smaller than the throttle body opening (and they gained horsepower)

[jran76]

ECS seems to have the best transition from 3.5" to 3". CTS, Roc-Euro, USP, and APR all do the same thing in one way or another. Maybe not the best, but hard to say....

Either way, I think it's safe to say that just about any intake is pretty marginal in either direction. If you're not trying to set records, it probably isn't going to matter a whole lot. I've now logged just about every intake except the full AWE system and Eurocode, and most log slightly better than stock (keep in mind, logging only tells part of the picture). APR was a small improvement (about the same as an upgraded filter/tube on the stock airbox). Roc-Euro, CTS, and ECS were all slightly better, but really close to each other.

[Fociracr]

Thanks guys for keeping this thread going I'm real curious myself now to see what the difference is between this one and the stock intake. I already started making another one tho one that's got a blocker plate like the CTS turbo intake, I've just been busy lately and haven't had time to do any playing around yet, but as soon as I do I will post it. I might just keep this one for the winter and use my CTS replica for the summer we will have to see. Plus I don't really think it matters whether the filter opening is 3" or 3.5" in the end it goes in the same size hole which is 3" I'm sure that .5" is very negligible. I'll update soon I hope.