For folks with E36 M3's, the following is a detailed description for installing the snorkel (BMW part #1371 1401 527 ~$40). The snorkel gives a second source of air from the top of the left brake cooling duct which, depending upon ambient conditions, can yield cooler air than the default source from behind the kidney grill.

Briefly, the snorkel resembles the stock air channel that conducts air from the front grill towards the airbox- except that the snorkel version has a sidearm that points down towards the left brake cooling duct. However, on many E36 M3's, the horn blocks access to brake cooling duct so the horn must be repositioned. A hole in the brake cooling duct must be cut for the snorkel (marks are provided on the brake cooling duct). Also, removal of a bottom panel from the spoiler made snorkel installation easier.

Total installation for me took about 90 min but I could probably do another in less than an hour. Detailed instructions for installing the snorkel with the Euro airbox follow; these notes should also be applicable for the stock airbox too.

1. Loosen 2 (10 mm) nuts that attach the airbox to brackets on the wheel well.
2. Loosen the hose clamp that attaches the hot-film air mass (HFM) detector to the air box and the hose clamp that attaches the HFM to the throttle body (the latter aids assembly)
3. Remove airbox from engine bay and push aside the HFM.
4. Remove the channel that conducts air from the kidney grill towards the airbox. Note how it slides up and out.
5. Remove the horn. A 10 mm nut attaches the horn to 2 brass strips. The strips must also be removed because they will block the snorkel. One of the strips can be bent and attached to the frontmost bolt that attaches the airbox to the wheel well (below). Removing these strips was uncomfortable because the 13 mm nut was upside down and difficult to reach. Detach the electrical leads to the horn and remove the horn from engine bay.
6. With a sharp knife and steady hand, cut the hole in the brake cooling duct. Cut inside the marks at least 1/4 inch! I cut a slightly too large hole- i.e. 1/8 inch inside the marks. After final assembly, I was left a small gap at the front of the hole which was covered by strip of duct tape.
7. Jack up the car from the left-front jackpad and remove from the bottom of the spoiler, the left-most plastic panel that attaches the spoiler to the frame. There are 3 screws (8mm) and 2 plastic fasteners within recessed holes. For the adept, jacking up the car is unnecessary, but I had to grip the inner stud of the plastic fasteners with needle nose pliers to remove the stud (these are hard to see unless the car is jacked up).
8. Pull the brake cooling duct down slightly (the end towards the wheel well). This will help positioning of the snorkel (below).
9. Install the snorkel (the hard part). The snorkel has 3 orifices: (1) the snorkel tube, (2) the narrow rectangular region with a small clip attached to a stud, and (3) the ellipsoidal end that attaches to the airbox. With the snorkel tube pointed down, slide the bottom of orifice 2 into the top of the slot between the radiator and the kidnel grill. Some force will be necessary. If inserted properly, the snorkel tube will be roughly positioned above the hole of the brake cooling duct. If the brake cooling duct is not pushed out of the way (step 8), the snorkel tube will hit the brake cooling duct and prevent sliding orifice 2 into position. This is the step that took me time to realize the importance of removing the bottom spoiler panel and moving the brake cooling duct (steps 7 & 8).
10. Reset the brake cooling duct to its original position and adjust the snorkel's foam ring to seal the snorkel tube within the hole cut into the brake cooling duct. This position is close but not the exact, final position of the snorkel.
11. Reattach the lower plastic panel to the spoiler and frame and lower the car.
12. Attach the airbox to orifice 3 of the snorkel. This took a bit of twisting to get the Euro airbox attached. The snorkel may move from its position; check the foam ring again. A small gap between the foam ring and the hole may not affect performance, but I covered a 1/8 inch gap along the front edge with duct tape.
13. Attach the HFM to the airbox. Tighten the hose clamp. Compress the flexible hose on the throttle body and attach the HFM to the throttle body & tighten the hose clamp.
14. Position the airbox's bolts into the brackets on the wheel well. Before attaching the frontmost nut, bend one of the brass brackets (step 5) and attach to the frontmost bolt. I bent one of the brass brackets in 2 places to position the horn; one bend was a right angle and the other bend was a twist of about 45 degrees. This allowed the horn to approximate its original orientation. After everything is attached, every item is firmly in place with no slop or random freedom of movement.
15. Attach the horn to the bent bracket and attach the horn's electrical leads.

After installing the snorkel and driving with windows rolled down, I could hear a slight, low-pitched whistling noise that might be attributed to the snorkel. However, I could not detect much of a difference in performance with the butt dyno while roaring up my favorite canyon roads. Parenthetically, Dinan mentioned that they've been unable to measure any power gains from the snorkel but they readily admit that their dyno does not accurately model air rushing past the snorkel at 30+ mph. I guess they need to install their dyno inside a wind tunnel :-).

96 M3 Boston Green/Modena, Euro airbox/snorkel/Dinan exhaust

suspension upgrades next! http://dsrna.agi.org/bmw_96M3.html 87 E30 325i Dinan 2.8L Stroker, Dinan chip/exhaust/Stage 3 suspension, LSD,

LSD, extrude hone intake manifold, E30 M3 alloy lower control arms w/ offset bushings. 58k mi, now for sale: http://dsrna.agi.org/dinan325i.html From digest.v4.n844 Mon Jul 15 18:13:42 1996
From: edpm3_at_earthlink.net (Scott Blazey)
Date: Mon, 15 Jul 1996 13:50:37 -0700 (PDT)
Subject: Re: M3 Ram Air/Snorkel to Brake Duct Retrofit

djchin's installation tips were good, but about a weekend too late to help me. Fortunately, Richard Biscevic and Dan Newman had posted good instructions and tips that helped me out.

A couple of notes on the subject:

The rear "snout" in the stock M3 airbox can be removed without cutting it. Its's kind of like a Chinese puzzle, but it can be done. (I should have videotaped it). The best tip I can give you is that you have to turn it sideways, then pull and roll it out the top. It will squeeze a bit and the airbox will flex a bit, but it can be done.

The horn, as originally installed, lies horizontally. By bending the horn end of the metal bracket 90 degrees, the horn can be remounted in it's original place, except it will be vertical.

The easiest way to remove and reattacj the horn bracket is with a 13" socket wrench and a long extension from the bottom of the car, once you have removed the left front bottom air dam cover.

The air intake channel from the front grill does indeed go on "hard" to the airbox. If you remove the upper left radiator hose, that will let you angle the right rear of the airbox back, giving you a better angle at inserting the air intake.

For those of us who shoudn't be trusted with sharp instruments, the replacement left brake duct with the hole already cut to the correct size is about $20. Then you have the original duct in case you ever want to return the system to original.

Except for getting the rear "snout" out of the airbox and reattaching the airbox to the front air intake, everything else came apart and went together very smoothly.

Any of you who would like a copy of the steps I used can e-mail me directly. This was an installation on a '95 M3, production 11/94.

Scott Blazey