HOW-TO:  M5 BRAKE DUCT RINGS for the E39 NON M-Series

 by Johnny Lange - Feb. 2005 

Here's an easy one.   I love the look of the aftermarket brake cooling duct rings that is available for the E39 M5.  After reading a little here and there on many M5 boards about M5 owners making their own rings out of, yes, plumbing supplies, I headed off to the nearest LOWES to see what was available.   Since the E39 540's have brake cooling ducts in place already, I decided to make a set of these rings to compliment the openings.

MODIFICATION:    M5 Brake Duct Rings for the NON M series E39's

COST:  Less than $14

TIME:  Less than 2 hours, extremely easy

TOOLS NEEDED:  Dremel (or similar) with stone and cutting wheels, razor blade,  tape, marker 

APPLICATION:  Any E39 BMW with brake cooling  ducts

This about as simple as you can get.  If you have a Dremel tool or similar, this can be cranked out in less than two hours.  

I purchased  couple generic stainless steel strainer sets for less than $5 each.   LOWES did have the already open bottom stainless rings available, however they were with the kitchen disposal units and had "DISPOSAL" stamped on the ring.   This mod is cheesy enough, no need to have "DISPOSAL" displayed on the car too.   

THE RINGS:

First step is cut-out the inner of the strainer set.  This is straight forward.  Just cut of the bottom portion as you see in the pics. 

Secondly, since the grill below on the E39's are significantly smaller (height wise) than the typical M5 grill, you will have to trim the top and bottom of the rings.  Make sure you these markings are  parallel before you cut. 

On the top side of the rings, you will need to cut out a notch as indicated here.  This is because the rings will be seated in the grill and a angle that they are pointing down at the ground.  This notch allows the rings to be seated better. 

Follow up all cuts on the rings with a smoothing  stone on our Dremel removing all burrs. 

CUTTING THE GRILL:

Since you have modified the ring already and cut out the bottoms, simply hold up the ring to the grill where your current brake duct is.  Center the ring perfectly within this grid of the grill and make two marks with a razor blade on the outside edge of the ring.  Remove the rings and score the  plastic with your razor over and over until you can cut out the center section.  Watch your fingers and be careful to make you don't slip and severe your finger off. 

Once you have removed the small center section, you should be able to tight fit your rings in this opening.  

FINAL MOUNTING:

Once have installed your new "hi-tech" brake cooling duct ring kit, put a couple of dabs of your favorite epoxy on the sides where the outside edge (or threads) of the rings are wedged against the edges of the cut grill.   * I have not done this yet as I am awaiting to install my BMW Aerodynamic front spoiler. 

The DINAN 5 with BMW Aero front lip and rings

Happy Motoring, 

Johnny Lange 

*Disclaimer:  This is merely an idea and I make no warranties or claims by doing this.  Use and make at your own risk, safety equipment is your responsibility.