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hey guys-
I have had the opportunity to learn a lot from this board and all it's members. Hopefully somebody can learn a little something from this today and keep it going.

When i first laid eyes on the e39 m5, i thought the 'sink drains' was a stock deal. It looked so sick, flowed so perfectly with the lines of the car, I just fell in love instantly. Years later when I finally got into bmw's (and then an m5) I realized it was just a brake duct setup, then down the line crossed paths with the AA intake. I think it looks sick, and loved that it had some function over form to it as well.

I looked at the kit a few times, and didn't see it to be very intricate. After reading up a ton on this forum and studying their design I thought it could be done (for less than their asking price of ~$1000).

I am not claiming the same gains as theirs, I am not claiming it's as pretty as theirs. Hell i'm not claiming ANYTHING, but for those of you that would like to tackle a project, here is my experience.


LETS BEGIN!


To do this project we have two parts.
1. the cold air intake part (getting cold air to the air boxes)
2. the cold brake part (getting cold air to the brakes)

For this you will need to
1a. route the air intake ducting from the bottom of the airbox to the brake duct stream
and
2a. allow air into the front bumper 'ducting' (sink drains or cut holes)
2b. install oem ducting ( black piece )
2c. connect ducting (black pieces) to oem metal ducts
2d. open up the fender liners on each side to allow air to flow to brakes.

Supplies.
1. you are going to need some type of 'rings' (if you want) or you can drill holes in your oem grill...up to you.
2. you are going to need some type of ducting. If you wanna be billy badass, hit up jegs.com and order some 4" brake ducting for $7. If you wanna be broke like me and pay for beer, then get some flexible aluminum tubing. I showed pics.
3. you are gonna need the oem ducts...i got you part numbers.
4. you are going to need an array of tools but that's besides the point.

Not that difficult. The hard part is having the patience to think it through. so here we go.


I didn't think I was going to take pictures of everything simply because I was anxious to get it done. After I got half way through, I said "hey, maybe i know some guys on the forums that wouldn't mind seeing some info" so i grabbed the backup camera and we started taking pictures.


First off, you wanna remove your bumper... it's easiest if you jack the car up a bit. two t50 bolts (where the AA rings would be) hold the bumper on, 3 8mm bolts in the fender wells, and a few 10mm bolts from beneath. The pass. side fender has your outside temp sensor so be sure to unplug it as well as the line for the headlight wiper sprayer-deal- pull the bumper forward and disconnect the fog lights, and set the bumper off to the side.

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Here is where you will see the "ducting". Don't ask me why bmw didn't do this from the factory I have no idea, but they basically didn't include the black plastic pieces. I took some pictures for you of parts numbers but i'm sure if you hit your indy / dealer and say I want the m5 ducts they'll know what you're talking about. These are basically going to butt up against your "rings", and slide into the metal ducting that is already on the car.

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jegs.com has the billy badass ducting for $70. or hit up a hardware store for this aluminum flex piping. im pretty sure AA uses this **** right here... if you look at their install pdf it's PRETTY damn close.

JEGS 63115 JEGS Brake Ducting


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with the bumper off, you can see where the airbox is drawing air from now. My plan was to hack that piece off and attach the ducting to this. we'll get to "how" exactly we did this later, but that's the goal.



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^^ this is how the plastic ducting slides into the metal ducting. This part will sandwich up against the front grill. some people choose to attach it, I felt it was pretty snug after all the mods. your car, your call.



here is in my ring selected. trace out the diameter of the ring on the grill. punch a hole with an awl, drill out center, cut it out, clean up the boogie woogies, and attach it via your favorite epoxy, liquid nails, whatever. This particular one had clips that we used gorilla glue on, as well as a silicone outside the back ring of. the rings sat pretty flush and tight but wanted to be sure.

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before you remove the metal ducting's via 3 8mm screws, hold the fender liner up and trace out the area you will need to cut out for the air to get THROUGH to the wheel. you will also need to run the AIR INTAKE ducting into this metal piece to get cooool air so prepare to tap into it. Measure how large your ducting is, and cut a hole in your metal oem ducting to fit the brake ducting in. Figure a way to secure the brake ducting to the OEM metal piece. I chose to shove it in, then cut tabs in it, and fold it back on itself. If i had that shiny metal tape I would've used some here...but i didnt. maybe when i buy the good ducting from jegs i'll figure a new way to attach it up.


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with any extra ducting you may have left over, be sure to act like a complete idiot while making fun of safety glasses and beer drinking techniques. for what it's worth, the new bud light is zamazing.

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next, you are going to need to attach your intake ducting to your actual intake arms. I chose to hack up the oem deals and attach the 4" aluminum ducting to it via the crimp tool (to size it down a bit) and some hose clamps. Also, drill a small hole in the bottom of the oem ducting JUST IN CASE water builds up. the oem one has it, so im not too worried about it.

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attach the factory oem intake arm (now elbow) to the intake box (with the oem hose clamp) and mount it with the oem 10mm bolt. Also re-install the metal ducting with your intake ducting coming off of it. stretch the ducting out so it's more pliable and bend around the objects in the way.

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slide the black oem ducting pieces into the metal ducting pieces. if you want to secure them together, do so now.

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now the obvious...connect the intake stream up to the brake stream. try and keep your curves to a minium and secure everythign tightly.

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put the grill back on via the 4 push cliips and that weirdo rivet deal. put the bumper back on, don't forget the fender liners (that you cut...sorry no pick...fml) so that the air gets through the rings and into the wheel well. put the bumper back on, connecting all the goodies. and voila...









results? i haven't driven the car yet (been in here editing and typing sheeesh!!) but i'm sure it will keep the brakes colder and hopefully the intake stream a little colder as well. if nothing else, i can say at least my 'rings' are functional. hopefully AA's 15-18 hp claim is somewhat accurate and if not, oh well i had a blast with my friends anyhow.

cheers mates!









 

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Thanks for the writeup. Ahhh, the old aluminum conduit pipe penis gag, that takes me back.
 

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Awesome!

If you really want to be billy-bad azz racer search McMaster-Carr for "High-Flow Duct for Dust" Stuff is the good to 275° F and has a smooth interior for great flow. Not too cheap but not gold.

What always kills me is the ribs on the inside are killing your flow. Someday I want to do the same thing as you but include some CFD to justify it.

Cheers and keep the beer flowing!
 

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Awesome!

If you really want to be billy-bad azz racer search McMaster-Carr for "High-Flow Duct for Dust" Stuff is the good to 275° F and has a smooth interior for great flow. Not too cheap but not gold.

What always kills me is the ribs on the inside are killing your flow. Someday I want to do the same thing as you but include some CFD to justify it.

Cheers and keep the beer flowing!
The ribbing inside the ducting used (and deftly so, I might add!) will have no adverse effect on performance here. The turbulence created by the ribbing MAY increase the temp of the air but I have a feeling it would be a negligible increase. We are merely trying to get actual ambient air to the intake stream instead of the choked, hot air from behind the bumper rather than trying to have any 'ram air' effect at high speed. The ram air effect will be evident in the brake cooling ducts though since they are much straighter/smoother from intake point to exit point.
 

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Great pics! Looks like a fun and productive time!
 

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Discussion Starter #7
The ribbing inside the ducting used (and deftly so, I might add!) will have no adverse effect on performance here. The turbulence created by the ribbing MAY increase the temp of the air but I have a feeling it would be a negligible increase. We are merely trying to get actual ambient air to the intake stream instead of the choked, hot air from behind the bumper rather than trying to have any 'ram air' effect at high speed. The ram air effect will be evident in the brake cooling ducts though since they are much straighter/smoother from intake point to exit point.

ding ding ding!! winnnar!
 

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The ribbing inside the ducting used (and deftly so, I might add!) will have no adverse effect on performance here. The turbulence created by the ribbing MAY increase the temp of the air but I have a feeling it would be a negligible increase. We are merely trying to get actual ambient air to the intake stream instead of the choked, hot air from behind the bumper rather than trying to have any 'ram air' effect at high speed. The ram air effect will be evident in the brake cooling ducts though since they are much straighter/smoother from intake point to exit point.

Choked? The air is supersonic...sweet lets shove that into our engines. Crazy ram air. :D

:nono: I disagree about the ribbing. While I cannot quantify it,...yet..., I would rather have smoothest ducting I can get. The engine is drawing in air like a vacuum and this air is moving quickly, thus you do as much as you can to not slow it down. The multiple bends is not helping the case as I agree, but you would be surprised what ribbing as apposed to bends does. Been there done that with actual racecars.
 

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Thanks for the write-up and the pics. Nice ears...Agree with you, you don't have to secure the plastic air brake channels from the sink-drain rings to the metal ducting. They are more or less rock solid when the bumper is attached. Tested at 150mph. No issues.
 

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awesome writeup. can't believe AA charges nearly a grand for some plastic ducting and minor fabrication work. :deal:

You will more or less achieve the same exact results as with the AA.
 

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Discussion Starter #13
as stated in the 1st post not claiming anything about efficiency, i am simply mirroring the AA kit, have a look at what they use, and dyno test 15-18 whp.


actual shots of the AA setup:





^ thanks to rembrant for the pictures!
 

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excellent write up w/ pics! Thats the spirit of a true DYI. Looks great!
 

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Nice write up bro. Wish I couldve been there to "help"... err drink... err help.
 

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Discussion Starter #18
the stock 'elbow' going into the bottom of the airbox has a 4" inlet and goes OVER the stock airbox. I kept / cut the stock pipe to retain the stock bend, factory appearance in the engine bay, as well as the mount to the front of the car (stability). the ducting was also 4". hth.
 

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Great write up. excellent effort - thanks...

FWIW - IMHO - Not sure if any of this helps

- regardless of the hose ribbing etc - the length of the tube that the air travels is longer than the stock horns = drag - and note the AA setup has a piece of metal that is out into the air stream - - your's does not - without this metal bit 'scooping' the air into the air duct, you run the risk of a lower pressure being developed at the inlet of the hose - as the air rushing by can create a drop in pressure - almost venturi effect...

So although you almost replicate the same concept - there are fundamental differences that can have a large impact... - no way of knowing for sure without a bench flow test etc...

Unless you live in a really hot climate and lag around town, I've always wondered if it's worth all the effort to fight the heat soak with this - watching the temperature readout - you'll note it begins to drop/improve/less heat soak once you go over 50mph...
 
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