E36 Under-body Trim Panel

Underneath the E36 (all models except ti compacts) there are two black plastic trim pieces found just behind the rear jack pads, in front of the rear wheels.  These trim panels fill an oddly shaped gap between the plastic fuel tank and the rocker panel / cabin floor.  They also have a small air dam protruding straight down to help funnel air around the rear tires.  The M Coupe has something very similar in the same location.  And just like on the M Coupe, this flimsy little piece of plastic is the first item to get damaged during any off track excursions.

The photo below (sorry for the poor quality) shows the right side trim panel, which had suffered a torn mounting tab.  This allowed it to flap about, doing little to control the air flow underneath.  The following photo shows the broken tab and the new panel.

Old and New Trim Panels IMAG1697

These panels are held in place by a 10mm stamped washer/nut at the front and an 8mm screw at the rear and further secured by being sandwiched between the fuel tank and chassis.

It’s a very simple job, the hardest part is actually finding the part numbers for these two pieces.  It took a lot of digging on RealOEM before I was able to narrow down the proper pieces.  Hopefully this saves someone the trouble.

All E36 Models (Coupe, Convertible, Sedan, M3) exc 318ti Compact:
TRIM PANEL LEFT: 51718130071
TRIM PANEL RIGHT: 51718130072

New Trim Panels

M Coupe Front Bumper: Shaved, Installed, Gaps Adjusted

As mentioned in my previous post, the front bumper on my M Coupe needed some love.  The holes from the license plate mount had to go, there were several curb scrapes along the bottom, and I wanted to shave the corner lights as I had done in the Spyder.  Might as well knock it all out at once.  I had to remove the bumper to work on the air intake setup anyways, so while it was off I took it down to a local body shop, the same guys that painted my Titan bumper.  The install is pretty straight forward and quick, the time consuming part is adjusting the panel gaps, which were terrible when I bought the car.  On to the photos.

These photos show how the corner lights were shaved.  A couple pieces from a donor plastic bumper were cut to fit the holes left by the lights, melted and epoxied into place.  Of course the clean side was filled, primed, feathered, sprayed, and cleared.

Back side of bumper, lights shaved. Corner lights plugged.

Since the corner lights were gone, I needed to do something about the leads and plugs that would have led to the bulbs.  I didn’t want to hack the harness, but still needed to protect against water intrusion.  Solution: silicone sealer over the end of the plug, nice and easy.  After it dried the wire was bundled up and zip tied to the larger harness, hidden underneath the core support.Silicone side marker plug

Now with the bumper mounted, the real work begins; adjusting the panel fit.  As I mentioned earlier, it was terrible from the factory.  Fortunately BMW does provide several means to adjust the bumper and headlights.  I based all my adjustments off the hood, which I wasn’t planning to adjust, though that can be done as well.  The bumper cover is fixed firmly to the aluminum crash bar with a handful of plastic rivets and two slots in front of the tires (hidden behind the fender liners.  So remove the screws holding in the fender liners, though you don’t need to completely remove them, just at the front.

In the photos below you can see two of the adjustments.  The bumper height adjustment is contained within the impact absorbers, using a 14mm Allen head bit to raise or lower.  The photo on the left shows it with the bumper removed, but there is an access hole in the bottom of the bumper cover that allows you to make adjustments with it installed.  There is another adjustment by way of the size of the holes in relation to the size of the two bolts holding on the crash bar.  There is space designed in to allow the bumper to be shifted slightly back and forth with the bolts loosened.  The final adjustment is inside the wheel well and is held on with three 10mm nuts, which you simply loosen to allow you to move the bumper cover up/down/left/right and align it with the corners of the bumper.

Bumper height adjuster Bumper corner adjustment

Adjusting takes lowering and checking the fit with the hood, making slight adjustments, rinse and repeat until it’s just right.  You’ll probably have to make a slight compromise between an exact fit and it being functional, the hood still needs to close without touching after all.

Front right gap adjusted

Now onto the headlights.  Each headlight is mounted to the body with four adjustable plastic mounts.  You can screw in or out these mounts from the body to raise, lower, bring forward or aft each light.  Once everything is set, you affix the light to the mount with a hex-head screw.  The adjusters will tend to turn with the screw, so I used a wrench to hold them in place.

Adjusting upper headlight mount Fitted headlight and finder

And just to show you what a difference this has made,  see the before and after photos.  Pay attention to the, now, missing amber corner lights and the gap near the lights.

Original hood gap Bumper fitted and installed

Even more plumbing, a little cooling

Okay, long time no update. I’m assuming someone out there is halfway interested in this, so I’ll keep going. Haven’t done a whole lot recently because: A. I work when I feel like it, no sense it making it a chore, this is a hobby B. Waiting on parts C. I’ve mostly been refining what has already been done.

43. If you recall a few posts back I had talked about the two catch cans, with one connected to a K&N breather vented to atmosphere. Well I refined that a little. Now that can has a length of 1/2″ ID hose run down to below the car. Same breather filter in place, but should keep most of the expelled gasses out of the bay. Side benefit is that my bay looks closer to stock, no K&N breather to catch your eye.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/breather.JPG[/IMG]

44. And here’s it from the topside. I also installed all the plumbing for the Rotrex oiling system. Attached to the top of the left engine mount is the magnetic filter, held in place with a T-bolt clamp bolted to a Nutsert into the mount. Pretty much all the plumbing is now complete with the exception of the IC coolant lines up to the front.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/plumbing_final.JPG[/IMG]

45. Reinstalled some of the heat shields. The left airbox shield is great for protecting the Deka battery mounted to the crossmember, while still leaving room to disconnect the terminals. The right heat shield needed a little modding to clear the AC line (in orange.) Some tin snips and a file did the job. The header is just temporarily mounted to check clearances. I’ll be making a heat shield for the AC compressor as well.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/rear_heat_shields.JPG[/IMG]

46. Here’s the upper (larger) AC line running through the quarter panel. I got a little worried about heat and chaffing, so I got some silicone covered fiberglass shielding (the orange stuff.) It was slipped over the hose then taped down with silicone tape at the ends to prevent the fiberglass from fraying.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/AC_line_upper.JPG[/IMG]

47. Here’s the lower line. Same job with the heat resistant sleeve.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/AC_line_lower.JPG[/IMG]

48. Both AC lines meet up at the OE hardline terminals. The large line requires a small section of the plastic fender-liner to be removed. Dremel made easy work of that.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/AC_terminal.JPG[/IMG]

49. The Rotrex oil radiator is mounted to the transmission using two M10 bolts and steel spacers to move it out forward. Web3.0’s normal setup is having the radiator perpendicular to the ground, with a piece of sheet metal bolted to the bottom as a air scoop. Since I have the Beatrush underpanels, I wanted to keep the bottom of the car relatively smooth. So I bent the bracket to allow the radiator the lay back. I then bent up a strip of aluminum to strengthen the setup. You can see the bracket (painted black) bolted to the bottom of the radiator going the upper right where it is bolted to the end of the transmission. This turned out very nice and is incredibly sturdy.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/cooler_rotrex.JPG[/IMG]

50. Of course the radiator doesn’t do a whole lot of good if it’s covered with an aluminum underpanel. Out came the cutoff wheel. You can see the area I removed in the upper right hand corner. Notice the mounting holes at the bottom. I’ve turned the one on the left into a slot, and did the same to right one right after this photo. This allows removal of this panel to change the oil, while leaving the rear “diaper” panel in place.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/underpanel_modified.JPG[/IMG]

51. I was somewhat concerned about the reduced airflow over the Rotrex radiator with it bent back rather than hanging down like Web3.0 intended. So I picked up a 4″ SPAL puller fan. Pretty tiny, but it’s a perfect fit for the radiator. I got a thermal switch (shown) which I intended to mount inline, but space became an issue. I’m now going to use a radiator probe, which is still on its way.
[IMG]http://www.strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_AL/cooler_fan_beer.JPG[/IMG]