Another HD intake and brake duct - The Unofficial BMW M5 Messageboard (m5board.com)

ArrestMeRed · 1st February 2004, 23:29

Here is a picture of another Home Depot DIY intake and brake duct job:

I was going to do a step by step instruction of how to do this, but I ran out of time and had to concentrate on getting it done and didn't document as well. More on that later. I'll settle for a description and a few pics.

I followed ELEVENS' lead with the fog light intake. I initially planned on using gutter screening, but realized it is far too thick. He told me about office equipment at Meijers that's made of black mesh. Target has stuff that’s similar, but is unpainted. For $5, I bought a paper holder, and used it as a donor. On the fog light housing, I scribed a line 1/4" from the edge:

and cut it out with the carbon cutoff bit on my Dremel tool. Using a white paint pen, I marked each corner onto the wire, then guestimated the size as I cut with tin snips. By trial and error, I came up with a good fit. Then I flipped it over and cut out the other side. Using hot glue, I attached the screen to the back of the fog light bracket.

I cut the bottom of the sink drain using a hack saw. I tried to use the metal cutting blade on my sawzall, but it quickly went dull, even while spraying WD-40 on it. I left as many threads as I could. I cleaned up the burrs with a bench grinder and Dremel. I painted the ring, and the inside of the aluminum ducting with Rust-Oleum satin black. People have reported having problems with dents and stone chips on the rings, so I put some clear film on it very similar to StonGuard. InvincaShield sells Avery remnants. It's far less expensive than the 3M that they use on their kits, and the Avery pieces are actually remnants from kits that NASCAR teams apparently use. For $10, you can get an 8" piece by 3 or 4' long. I cut out rings from this, and put it on the flat surface of the sink drain. It made the satin paint look glossy, so I applied a light coat of satin over the top of the Avery material (the ring on the right). The ring on the left has just the Avery applied.

I removed the factory intake runners from the airbox. Not too difficult, just don't forget that each runner has 2 screws attaching it. The upper screw on the right side intake is very difficult to find, but it's right next to the fender, just inside the wheel opening. You can see the butt end of the screw pointing right at you, sticking out of the bottom of the weld nut (the bolt points to the rear of the car). I did the drivers side first, and got away without removing the wheel. I jacked up the car, and turned the wheel all the way to the right. It was tight, but I did it. If I were doing the brake duct at the same time, it would be necessary to remove the wheel.

After removing the intake runners, I cut off both ends using the sawzall. It was trial and error getting the shape of the runner right. I also moved the horns out of the way on the drivers side for better access. I loose installed both ends of the original intake runner in their final position, with the aluminum elbow connecting the two ends, and put them into position. I removed more material as necessary to get the shape I wanted. Once happy with the shape, I ran a strip of black duct along the side of the tube to hold the pieces and angles in place. I wrapped the whole piece in black duct tape. Before starting this project, I thought that opening would be too small. The intake opening of the factory tube is actually smaller than the cutout for the intake screen that I made. I used the tape to secure the leading edge of the tube to the surrounding area of the bumper to channel all air coming through the intake screen up into the runner. This is a picture of the right side.

I did the left side first, and didn't have time to do the right side. The next morning, after dropping off my son at daycare, I accelerated hard through the gears to see if I could hear/feel a difference. Then the SES light came on! I guess that means the engine noticed a difference in flow, and didn't like it under heavy throttle. Also, when removing the airbox, there was lots of dust and dirt trapped in the folds of the filter. Shaking that off probably was significant on its own.

The SES light didn't go out, and a few days later the engine started hesitating. Before doing the mod, it occasionally did this in 3rd or 4th gear at 1600 rpm or so. I asked the dealer about this, they checked the codes, and found no faults. I figured it might be heat soaking, and is part of the reason I decided to do this mod. After doing the left intake, performance progressively got worse, and I finally parked it until I could get the right side done. After I did the right side, the engine seemed to notice after a few minutes, and it kicked in like pressing the Sport button. The next few times I drove the car, it did this. Now, it seems to be completely normal. Actually, better than before! Now it doesn't seem to hesitate at all. But it's hard to tell with all the snow and slop!!

By the way, I got stuck in nasty freezing rain and frozen/slushy roads. I was afraid the small grating on the intake grill would freeze over, and choke the intake shut. My fears were unfounded!

One question - will the SES light turn off on its own once it realizes everything is back to normal, or do I have to have the dealer reset it? I hate to point out the fact that I've been tinkering with the car.

Next was the factory brake ducts. It’s necessary to remove the front wheels to do this, but no accessories like the horns need to be removed. I did remove the factory brake ducts (3 screws) to get it out of the way while I sized my pieces. I marked the holes on the grille using the foam spacer ring that came with the sink drain, and marked the circle with my white paint pen. I cut the hole with the Dremel using the carbon fiber cutoff bit. I had to buy a right angle attachment for the Dremel, which worked like a charm.

This wouldn't have taken nearly as long if I would have used the inexpensive factory brake duct pieces. But I didn't find out about them until after I bought materials from Home Depot. I bought 3" dryer ducting, and spent a lot of time attaching it to the ring that screws to the threads of the sink drain.

As I found out later, this won't work. There is an obstruction just behind the opening for the brake intake that took away the room that I needed. So I ran out to Home Depot and bought more aluminum elbows (2 per side). I removed the leading piece of the elbow for a sharper turn. This left the flanged end of the elbow at the leading edge, which fits quite nicely into the sink drain opening. I used duct tape to hold the position that I wanted, and using the same trial and error technique I used for the air intake, I found the shape that works and locked it into place with duct tape. Then I removed the tube, and wrapped the whole thing with duct tape. I taped the leading edge thoroughly to the back side of the sink drain just like I did with the air intakes, and used a thick tie strap around the middle of my duct to hold it in place.

Voila!

ELEVENS · 2nd February 2004, 17:59

Hey A.J.- that looks really, REALLY good. I am completely unbiased, of course!

Like you, I did one intake side at a time, and also got the SES light in-between. Apparently, the ECU can see a difference in flow between the stock intake and our foglight intakes. Once all is well again, I believe the ECU needs a certain number of "clean" start cycles before it extiguishes the SES light.

You mention heat soak. From the looks of those icey pics, you're kidding, right?!

I just got a code reader and SES light reset tool, the Peake Research R5 FCX II. Works really well, easy, and fast. Every USA M5 should come from the factory with this device in the glove box!

Enjoy!

ArrestMeRed · 3rd February 2004, 03:38

Thanks for the heads up on the SES light. I'll be patient. I don't drive a whole bunch of miles, so it may take a while.

My air filters had all sorts of dust in them. When I held them up to the light and shook them, it was almost as if I was emptying out my wet dry vac! There was also a little bit of dirt accumulated in the bottom of the filter box.

The car's running better than it was before any of the mods. I'm so happy. Unfortunately, it doesn't sound any more aggressive. A common 911 mod is drilling holes in the side of the airbox. The factory motorsound option does the same thing. And it makes a substantial difference in sound inside the car! From outside the car, you couldn't tell.

Yes, my car would hesitate, kind of stutter, at about 1700 rpm in the taller gears. Didn't seem to matter what the temp was outside, and really didn't always point to heat soaking - it was kind of wierd. That's why I had the dealer verify there wasn't an actualy problem. It wasn't a big deal - I don't usually drive in that low rpm range, anyways. But now it runs extra smooth. I can't wait for these #*$% roads to dry off!! I've spun my tires in a straight line in 4th! Of course, the OEM Dunlops probably have something to do with that...

ELEVENS · 3rd February 2004, 04:07

Quote:

Originally Posted by ArrestMeRed

Thanks for the heads up on the SES light. I'll be patient. I don't drive a whole bunch of miles, so it may take a while....

My air filters had all sorts of dust in them. When I held them up to the light and shook them, it was almost as if I was emptying out my wet dry vac! ...

Before I got the Peake tool, sometimes I could clear the SES light by "convincing" the ECU that all is well by cycling the start/stop/remove key routine several times.

Regarding the filters, I change them often (6000 miles) in the beast.

mottati · 25th June 2004, 00:41

Found this thread, and it was very similar to what i did. I also got a recurrent SES light. Do you guys who did this mod still get an ses light? I ended up pulling out my ductwork, for now anyway, until i figure out how to do it without the ses light and airflow sensor code.
thanks,
Mike

ArrestMeRed · 25th June 2004, 20:14

No problems with the SES light, not for that anyways. It did come on the day that I ran with one intake modified and one stock. Once I got the whole job done, it was off and on, and occasionally the engine hesitated when at idle (no SES light, though). I thought I needed the ITAS kit, which I bought. I was leery to install it, and am glad I didn't: it took a few trips to the dealer, but they finally found error codes. Turns out the O2 sensor was bad, but the problem didn't go away. Later, they found the mass air flow sensor was bad. I still haven't installed the sensor, and am glad I haven't so they don't try to blame me for any of the issues. I'll wait until I'm in the clear before doing the IATS.

cali6869 · 3rd September 2004, 09:49

very nice... this will be my 1st mod..... If i get the car next week...

warhaven · 5th September 2004, 00:52

That's totally awesome.

I have been wanting to do this mod. I love the aftermarket CAI mods that use the center ring intake. and the fog lights make a perfect brake duck mod.. Looks awesome. I am planing on the same mod but want to use rustolem's hi temp paint... in either crome or gold... haven't decided yet which as me car is jet black.

ELEVENS · 5th September 2004, 14:55

Quote:

Originally Posted by warhaven

... I am planing on the same mod but want to use rustolem's hi temp paint... in either crome or gold....

JMO:

I have a "true confession" to make: I once bought a set of gold plated emblems for my Polo Green Corvette. Reality set in, then sold them right away, but have been embarrased about that ever since. I must have been on the pipe! One word: Garish. OK, I just looked that word up in the dictionary to make sure it meant what I thought it meant. Yup - synonym: Gaudy.

If gold floats your boat, knock yourself out. Just beware how others might view it. Please don't take this as a slam, it certainly was not meant to be. I'm just looking out for my fellow ///M5 comrades.

-Bill

johnv · 5th September 2004, 16:37

Quote:

Originally Posted by ELEVENS

JMO:

I have a "true confession" to make: I once bought a set of gold plated emblems for my Polo Green Corvette. Reality set in, then sold them right away, but have been embarrased about that ever since. I must have been on the pipe! One word: Garish. OK, I just looked that word up in the dictionary to make sure it meant what I thought it meant. Yup - synonym: Gaudy.

If gold floats your boat, knock yourself out. Just beware how others might view it. Please don't take this as a slam, it certainly was not meant to be. I'm just looking out for my fellow ///M5 comrades.

-Bill

Gold. You must be kidding???

The idea is to have everything look stock and not stand out. The cleaner the better. JV