heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Couple more quick distractions.

Swapped temporary injector o ring on the IAT with one from WOLFN8TR:



Also attended a fairly wet autox this weekend. Lots and lots of spinning out. Was a blast.

Sheep seemed to be enjoying the weather:



During a couple of the many spins, I learned what ice mode feels like on the MK60. First time it happened (spun 360 deg, feet on clutch and brake, brake pedal pulsing, car rolling backwards at ~20 mph and not slowing down much at all), I thought that ABS was just not very good at slowing the car down in reverse. Pumped the pedal and car came to a stop. However, it happened again at a much slower speed (~10 mph) and it felt distinctly different to normal ABS engagement.

Pedal was pulsing, but the pulses were way lower amplitude than during a normal ABS event. Pedal also got very hard after ~10% travel and additional force from my leg did not translate to any meaningful force at the calipers. Felt similar to pushing it with the engine off and vacuum gone from the booster. Again, couple pumps and the pedal went back to feeling normal.

Thinking back on this, I'm pretty sure the conditions (and my terrible drifting abilities) were triggering ice mode. Pumping the pedal was an almost instinctual reaction (kinda like flicking a switch a bunch of times when it doesn't do what you expect), so it was not as scary as I thought. I bet it's WAY scarier when going into a corner at 120+ mph though!

[heinzboehmer]

I thought about sealing in the grommets, but was not confident that I would be able to keep everything moisture free underneath the undercoat. I do have to say that for some reason the seam sealer thing did not cross my mind though...

I might end up doing that at some point in the future, since the area is easily accessible.

I have used 2K stuff before and agreed that it is miles better than regular rattle cans. However, there's no way I'm spraying that stuff inside a garage with poor ventilation. I don't think I would be able to keep the fumes from entering the house, which is not something I want to have to deal with.

And yes, I know this is essentially a huge overreaction lol. Just figured it would be much easier to solve at this stage, so went for it.

[bmwfnatic]

I would have used a 2k epoxy, and then sealed in the grommet with seam sealer on top. Also this rust is a joke lol, on Euro cars there can be a 15cm2 rot hole there 😂

[heinzboehmer]

A few quick distractions from the (obviously more important) euro cubby project.

First up, yearly brake flush. Didn't see tons of bubbles, but fluid had seen better days:



With the car up in the air, I also replaced the trim around the RTABs, as it was starting to fall apart:




Unfortunately, I also noticed this while under the car:




Guess the years are starting to catch up to the M3...

Fortunately the rust was super minor and there was tons of good metal underneath:




I also found a tiny bit of rust on the tabs that hold the plastic panels and the v brace mounting points. But, once again, lots of good metal underneath:







Strategy for solving this is the following:

• Expose good, bare metal
• Few coats of POR15
• Wait for it to fully dry
• Clean with isopropyl alcohol
• Hit the area with a heat gun to make sure there is absolutely zero moisture left
• Few coats of rubberized undercoating
• Few coats of SEM EZ Coat in olive green
• Reassemble and act as if nothing ever happened

Since I was going to be spraying thick undercoat, I needed to figure out how to mask the areas where the rubber grommets and v brace attach to. Decided to print out some plugs to leave a nice perimeter around the holes in the chassis.

Given that I was printing the plugs, I was able to precisely control the clearance between the undercoat and grommets/v brace. Opted for a much tighter clearance than factory (1.5 mm for grommets, 3mm for v brace):






Grommet plug is a three piece TPU/ABS design. The tapered insert screws into the plug and expands the TPU against the chassis. This keeps it firmly in place, but also allows for easy removal.

V brace plug is just ABS with a threaded portion that screws into the chassis. Only important feature is the taper on the plug used to leave room for the welds on the v brace boss.

My hope is that a tighter clearance will help keep rocks and other road debris from chipping away the POR15, which should help this repair last longer.

Here's how everything came out:




End result is okay. By no means professional grade, but I'm incredibly incompetent when it comes to anything paint related. It is raining this weekend, so a couple drives should be enough to hide any imperfections. Just happy that the rust is properly addressed!

[heinzboehmer]

Put me in line too. I've always liked this cubby and this is a super clever solution.

Totally!