It was a cloudy day at Gingerman Raceway. I eased into the throttle exiting turn 10 of the 11-turn track. Rumbling and tumbling down the back straight at 140 mph, the 1 ¾ ton girl is a moving.

Slam on the brakes at the 300ft marker, and it’s not stopping. Simultaneously, it’s pulling hard to the right and on the verge of a spin. Past the 200ft marker, I’m applying and releasing the pedal; maybe I’ve bled off 40 mph. Past the 100ft marker, it’s starting to straighten up but still going 90. I crest the track exit road and finally lose enough speed that I won’t hit the embankment at the end of it. Still sizzling coming into hot pits, wondering what the f*** just happened?

Well, I’ll tell ya. One of my five radiators fell out of the car.

The one that matters

The F82 M4 has five heat exchangers, which is about four more than anybody wants to think about. The only one that matters here is a small auxiliary cooler that feeds the main radiator. It lives in the front bumper behind the driverside duct, tucked right behind the splash shield, a few millimeters from the tire. When it came out, the hoses were pointing straight at the inside of my wheel.

That’s the entire story of that braking zone. No grip on the left because the tire was getting hosed down with water and coolant additives, and no brakes on the left because the caliper was getting the same treatment. Everything that still worked was on the right side of the car, so that’s where the car went, and it damn near took the back end with it.

Radiators don’t just fall out of cars, Devin!

I know what you’re thinking, because I was thinking it too if you saw my Instagram story. How did I manage to goof this up? I had most of those coolers off to do the crank hub.

Here’s how they mount. The coolers sit in a plastic shroud. Cages are what I call them. You push them up into fangs at the top, and those fangs hold them in. The intake side (from the bumper duct) has bracing to prevent them from falling forward. The exhaust side is held in by the fangs and what feels like a press fit, and that’s it. The backup plan is that the splash shields for the fender and the under tray on the bumper all bolt together. The hose connections are on the back, so if a cooler were to ever dislodge, it should just hang out in the bumper and go nowhere.

So whose fault is it? Partially mine. I didn’t have the bottom splash shields on. They weren’t on the car when I bought it, they’re fragile, and like the oil cooler from the last article, they don’t seem to enjoy being attached to the vehicle.

Can we blame BMW? Absolutely. You’d think it would be harder than this for a radiator to fall out of a car. I asked the track F8x group whether this has happened to anyone, and it has, more than once. Consensus is that it’s rare, but it isn’t new. If the plastic casing cracks, it loses its grip on those fangs, and the cooler can slide out on a big enough bump, and Gingerman’s braking zone has big bumps. Someone else pointed out that any minor accident or road-debris hit is enough to start the cage to crack. One guy ordered a used replacement, and it showed up cracked too.

What Now

Where does that leave us now? Going to design a bracket to sit in the back of the OEM coolers they can’t physically come out. Since this one that eject-o seat-o out of the car is trashed, I may look at some aftermarket unit for the driverside. Given the cost, it’s hard to justify, especially without proof of a cooling issue. Also, before I forget, I couldn’t find an aftermarket auxiliary cooler without the mounting bracket built into the cooler itself. There is no way they can suffer this unless you tear them off the end tanks; if you did that, you’d likely have other, more pressing issues. Wonder why BMW didn’t use their team of engineers to do that.

That last one is the real story from the weekend. The F82 is fast. Genuinely fast, faster than any project car I’ve owned, from a stock-powered 987.2 Cayman S to my 470hp S2000. The weight doesn’t scare me under braking. But it does not turn in like anything else I’ve ever tracked. That girl was crying for help on the out lap. It’s on decent street tires, but nothing like today’s Super 200TWs, and they’re only 275s, which are pizza cutters on something this heavy. The car is begging me to take drastic steps. Driving first. Then we talk tires.