From digest.v6.n845 Thu Jul 3 15:30:51 1997
From: sbogard_at_VNET.IBM.COM
Date: Thu, 3 Jul 97 13:05:05 EDT
Subject: re: e36 (the plastic thing under engine) AKA "The Shroud"

There is some discussion going on here that is a little confused. One person speaks of their plastic shroud getting blown off, & a newer metal one available. Another speaks of a part off a '88 BMW fitting on a E36. Let me share some facts:

1. The '95 M3 Shroud does blow off. Look at the E36/M3 pages (Dale's pages)

   for some stories. Option 1: replace the old '95 shroud (beware, the plastic clips it bolts onto may be torn as well, then you're replacing more than just the shroud, you're replacing the side wheel well plastic.

2. The M3 LightWeight has a metal & plastic shroud. The pan bottom is

   aluminum with a hole cut out. I think the hole is to allow air from the M3 LTW splitter to ram in. Also, the hole is there to let water out (on the '95 plastic one, water is let out through a round catch basin with holes). Option 2: replace the plastic shroud w/ a M3 LTW part. You will still have plastic tabs that can tear (the LTW part again is an aluminum pan with plastic sides (but no round catch basin). You'll have to do something with the hole (installing a splitter would be fun).

3. The '97 M3's now have a lighter weight plastic part than the old shroud.

   It is less likely to tear because 1. it doesn't have the rain catch basin

4. it doesn't hang as low, hitting speed bumps 3. it is lighter in weight so gravity doesn't pull on the plastic tabs as much 4. it has a much smaller air pocket to catch air, so presumable it looks like it doesn't catch as much wind drag trying to rip the thing off.

Now, the only downside of the '97 setup is, I slightly lied. It isn't just a single part change. You have to change out the side plastic parts running up into the wheel wells. Plus maybe some other parts. This is from crawling under many '97's at the dealership on Sundays when the dealership is closed. Another thing, the '97 doesn't visually appear to sit as low to the ground. This is because you can notice the low hanging '95 shroud as a dark shadow. The '97 allows more "daylight" to be seen under the car, so it looks higher.

I think the LTW part might be the best bet for '95 M3 owners, except it costs a lot more than the plastic part, and it still has those stupid plastic tabs. It is P/N 51-71-2-268-673 "Air Duct" $280.90 list. The '95 plastic one is $80. Remember, the LTW one will bolt on instead of the '95 one, but it has a big slot in front to grab air off the splitter. I don't know how it would behave without one. It might resonant (AKA flapping in the wind) at high speeds. At resonant frequencies, things tend to break or blow up, ala Tacoma Narrow Bridge style. I've spent some time under a M3 LTW, but I don't understand how the splitter adjusts up & down, nor can I visualize the airstream workings.

I'd really be interested in anyone going through the exercise of trying to convert the '95 shroud setup to the '97. It looks expensive to do though, but I only have microfiche for the '95 and LTW, not the '97 so I'm not sure.

As far as that '88 piece, it looks like that on a '95 will make the car even lower, so it would scrape on speed bumps even more. At least the LTW pan and the '97 new parts give you about 1 1/2" more underneath clearance because there is no round "catch basin" for water.

• - Skip