[M3] Sport Evo front splitter

[note: this post, like an air-cooled 911, is back-dated to when these events occurred] 

Five years ago, shortly after I bought my first M3, I bought a Sport Evo splitter setup from Markus. And for five years, I didn't install it. My enthusiasm for Sport Evo parts waned as I realized the extensive refurb work that the car required. I didn't want to put a bunch of hot shot parts on a car that wasn't up on basic maintenance, and I never felt like it was the right time with the DS car. So the splitter parts lived in the shed, then the garage, then moved house with me, into a new shed, back into the garage. The DS car went but I held on to the splitter, along with the other parts that had taken me a while to collect.

As soon as I brought the Lachs home I was making plans to finally install the splitter. I had plans to take care of a few other things that involved removing the front bumper, and I was trying to work up the nerve to drill dozens of holes in my front fascia. Last night I was poking around with my fog lights when I noticed something.

Well well well. I'd be upset if it wasn't the perfect situation for me. So today was splitter day!

I was relieved to see that all of the bits and fasteners and gasket parts had survived through the years and stayed together. All of the kit parts are OE except for the lip, which is a CF replica piece. The OE lip is NLA/expensive and I know that, despite my best efforts, I will at some point smack a curb or parking block.

This is my first time pulling an E30 bumper and it was very simple. I wanted to do four things while I had the fascia off: install the splitter; remove the front license plate bracket; remove overspray from my A/C fan; and correct whatever is going on with my front turn signals. The eagle-eyed among you might have spotted in previous photos that the turn signals are way sub-flush in the front fascia, and I wanted to see what was going on. The front end has been repainted and some shortcuts were taken, so I wanted to dig in.

The first item in splitter install was to press the small seal into the plastic undertray. Next, I offered the undertray up to the fascia to confirm that this mysterious past modifier actually drilled the holes in the right place. Thankfully, they had. Markus's CF replica lip comes without any fastening holes, so the next task was to mock up the lip and mark the holes for drilling.

If you plan to run the least-aggressive ("Monza") setting, you will need to remove additional material on Markus's lip to clear fasteners that hold the plastic undertray to your fascia. You can see slots in the OE plastic lip for this purpose. I set my car up for the middle "Normal" setting, so there was no clash and I didn't need to make additional cuts. The image below shows where you'd need to make clearance holes in the lip (silver Sharpie pointing at the hole).

So with all holes drilled, it was time to make sense of the bags of fasteners. I had a tough time finding really clear images of the assembly process so here are my contributions to the story. To get started, the Evo undertray is secured to your bumper with 12 plastic rivets. These are quite stout and need to be hammered home once you get your fitment set up.

The same plastic rivets are used to secure the smaller panel that supports the oil cooler. You can fit this in one of three positions so that the slot is fully open, half-open, or closed. According to Markus's old posts, these different settings allow you to tune airflow through the oil cooler. I don't think I'm doing any driving that will stress my oil cooler so I opted to go with the half-open setting because it looks cool. If you are debating which way to go, I think it is worth mentioning that the entire Sport Evo splitter setup obscures radiator-area access from under the car compared to the OE US arrangement. I already wish I'd just kept the aperture full-open to ease future work.

Because the rivets require so much force to install, I'd recommend doing the oil cooler panel before the whole thing is on your bumper. But if you're like me and no one told you that, try to back up the rivet while you hammer on it. A 10mm deep socket does a nice job supporting the backside and is large enough to let the rivet expand to installed position.
These 6 screw fasteners are intended to support the 'center' of the plastic undertray into your fascia. Interestingly, the trim on the US bumper seems to be different from Sport Evo and these edge-grabbing clips only fit in the two most outboard locations. So four of them went unused and were replaced by some M6 nuts and bolts I had available.

The completes the installation of the plastic undertray and oil cooler panel to the bumper. Bolt up your splitter in 12 places.

With splitter installation complete, I went after the other bumper-related items. I drilled out the plastic rivets retaining the front plate bracket and used acetone to remove overspray from my A/C fan. I pulled off the bumper reinforcement to understand why my turn signals were askew.
The turn signal assemblies are supposed to bolt up to the fascia. The back side of the fascia has thin doghouses that receive a very peculiar, thin, clip-on-M6-stud deal that is long NLA. It was probably NLA when this bumper was painted. Rather than try to think of something clever, the body shop doofus decided to fix the turn signals to the bumper reinforcement with big long self-tapping screws. Ew. Now, the joy of old car fixin' is that you don't know what parts you need to order to fix a problem until you're already in there. And I have plans to use this car tomorrow, so leaving it in pieces while I waited for parts was not an option. Putting those self-tapping screws back in there was also not an option. What to do? I can't fit an M6 bolt with a normal head on it because the doghouse is so thin. Well... remember how 4 of those 6 edge-biter clips didn't work earlier?

Yeehaw. It's not pretty, and it's not permanent, but it will hold while I get the correct parts to fix the problem. The edge-biter clips fit well on the doghouses, and I stacked washers to get decently close to the right offset with the screws available. It will be annoying to pull the fascia again, but it is going to come off again anyway when I install my Evo bumper gasket. In theory I could have done the gasket today but I didn't want to introduce too many variables in a single project that needed to wrap by tonight. From what I read, getting that gasket to play nice can be an ordeal.

First look with the bumper back in place. Yeah! And then came... the wrangling. The final important part of the splitter install is how the rear of the plastic splitter undertray interfaces with your original undertray piece that slots in with the wheel liners. It seems that the Evo version of that piece with the brake duct holes has a different trim that meshes more harmoniously with the splitter piece. Wish I'd known, would have grabbed one back when they weren't NLA. In any case, the original undertray can be reinstalled above the new piece. I had to pull the wheels off to get enough space to jam it in there. It's sort of an uneasy truce of who's supposed to be where between the two undertrays. I need to come back with a good strategy to fasten the trailing edge of the splitter undertray to the original undertray. I am interested to hear ideas on the best way to do that.

I wrestled with undertrays all through dusk and finally got the car back on its feet to see the results. Big thumbs up. I'll find some plugs for the license plate holes but otherwise it's all looking sharp! Only took five years.

The front end will continue to improve next week, when I should get all of the parts I need to install euro grilles and my NOS Hella ellipsoids. Stay tuned...