2009 BMW M3: Fixed, but in a Temporary Way

I agree, this is just plain awesome! I never thought I'd be this attracted to some screws and metal pipes but the M3 has proven me wrong.

It's interesting that the undercarriage(?) is stamped with "E9X" instead of "E90" for the sedan ("E92" for the coupe and "E93" for the convertible).

That sliding rear brake caliper looks so small. I'm tempted to say the fixed rear 2-pots on my WRX are almost as big.

Also, does anyone know why BMW used fixed calipers (Brembo I think) on the 135i but not the M3?

Subytrojan, could it be that panel is stamped E9X because the same part is used on all models? The undercarriage of my E46 3-series is still clean (relatively) after almost 93K miles.

@subytrojan

Those small calipers have a pretty big impact, even though the fronts are obviously where most of the stopping power is, considering the car stops from 60 in 100ft!

Ok, so how should the undercarriage look since it rained?? Dirty?? Rain is water correct? Unless you guys in Cali salt the roads when it rains.

When you start to poke around the nooks and crannies and see finned differentials and aluminum suspension and subframes you begin to realize why the car costs $56K.

Am I the only one to notice the oil leak at the top of the differential?

bimmerjay, even my lowly ti came with a finned diff cover! If you want to see a REAL finned cover, check out the one on the E65 Alpina B7:

http://www.carspace.com/roadburner/Albums/B7/IMG_0628.JPG

@roadburner,

Yeah but they're still expensive. Your ti probably had an LSD like most BMWs before the advent of DSC. I saw the Alpina's up close, it was pretty crazy.

@desmolicious,

That's just speed fluid, nothing to worry about.

" desmolicious says:

06:08 PM, 12/14/09

Am I the only one to notice the oil leak at the top of the differential?"

Good catch. Yup, definitely a leak there. Doesn't look like anything substantial, but something that an eye should be kept on.

I don't think that's a leak. Here's why:

I believe the M cars still get a 1000 or 1500 mile maintenance, which includes a diff fluid drain and re-fill. On a fill-to-overflow diff, that looks like the exact amount that would overflow before you'd re-bolt the fill hole.

I'm guessing it's leftover from the early diff maintenance, which is cool to see that it actually got new fluid back there :)

Just my take. or it could be a leak. :)

...

I am really impressed by the organization of the underneath of that car. That rear diff is seriously finned and looks like it has two drain bolt holes. I wonder why. The exhaust is beautifully heat-shielded and i like how the pipes have an aluminum 2-finned attachment to rubber mounts. I saw a e90 330i (2006) with some stock muffler pipes that were bouncing around when the car hit bumps. I bet this execution will stay tighter over the long-run.

I count at least 5 chassis-braces that don't need to be there. Awesome stiffening of the chassis for the M-car. Plus I love the execution of the rear lower control arms and how they attach to the frame next to the exhaust in the last picture. It just looks deliciously executed.

The rear caliper looks puny, although it could be just the awesomeness of that rear rotor. It appears as though the entire face is being swept though, so it's obviously working. Plus caliper size/piston count means so little and has been so overhyped, this just re-inforces that. Also, that rotor is a really nice two-piece design that looks like it could take all-day hard braking from 150mph.

Lastly, that's about what the underside of my PA cars look like until after the first salty winter. Then it's dirt, discoloration, surface rust, and a general disgusting grayness.

Maybe someone should just clean off that 'leak' with some contact cleaner, and see if it comes back?