From Street to Apex: My BMW 128i’s First Track Day

It’s been a long time coming. I bought this beat-up E82 128i two years ago with the goal of turning it into a track car. Safe to say, procrastination played its part.

After the long and sometimes painful process of bringing this pile of bolts back to life, something unexpected happened—I realized I actually loved it as a street car. I found myself hesitating to strip it down, make it loud, and ruin the ride in pursuit of lap times. It was just too enjoyable as a playful street car that can be driven everywhere.

But as much as I’ve loved driving it on the street—and will continue to—it eventually became clear that the car’s next evolution was calling. It was time. If you’ve been following along, you’ll know the 128i has recently undergone some serious "car surgeries" in preparation for track duty. I dropped the subframe to install an oil pan baffle, tore off the entire front end to fit a 135i oil cooler, upgraded the brakes to handle repeated hot laps, and recoded the ECU/DME to keep the electronic nannies from spoiling the fun. Those mods were combined with the larger all-aluminum CSF Racing radiator I installed on the car shortly after I bought it.

Yesterday, I finally put it all to the test at my local track—High Plains Raceway. With its high elevation and thinner air, cooling can be a real challenge, so the big question was: would the car hold up under pressure?

The answer? A resounding yes. The 128i ran like an absolute champ—reliable as an anvil, without so much as a hiccup. Since the 128i doesn’t have any sort of temperature gauge on the dash—and I didn’t think to use ProTool as a logging device—I can’t give you exact oil or coolant temps from the sessions. That said, we were running in 80+ degree weather at high elevation, and the car never once hit limp mode or showed any signs of distress over three full 15-minute sessions. So whatever temps it was seeing, the DME clearly didn’t think they were worth complaining about. I’ve driven at High Plains Raceway before, but yesterday was my first time running the shortened West Course. My best lap over three sessions was a 1:44.512. I can’t really tell you how that compares to the full layout, so the time itself doesn’t mean much—but what does matter is that I had an absolute blast.

I ran with a local SCCA Time Trials group, which uses a modified ruleset that happens to work well with my 128i’s current power-to-weight ratio. In other words: if I want to stay competitive in this class, I can’t add much more power or strip out weight. That’s actually a win in my book—it means the car gets to keep its full interior and won’t be saddled with an obnoxiously loud, ear-shattering exhaust. It can still be a respectable street car.

There were seven of us in class, and I ended up finishing fifth. I held onto fourth for most of the day, but one competitor edged me out in the final session—by less than two-tenths of a second! Third, fourth, and fifth were separated by just about half a second total. Honestly, I’ve never been so happy to get my butt kicked and land in the bottom half of the scoreboard.

So, how did the car feel? In short: it did some things well, and there’s definitely room for improvement.

The standout trait was understeer. The car was easy to drive and didn't really feel like it was trying to kill me—a refreshing change. The last Time Trials event I attended, I was behind the wheel of a short-wheelbase 1988 Honda CRX Si with stiff rear springs, poly trailing arm bushings, and a massive splined rear sway bar. That car was a real handful—ready to spin if you so much as thought about lifting off the throttle mid-corner.

By comparison, the 128i wasn't nearly as terrifying. Even on a square wheel and tire setup, its default behavior when pushed is understeer. While not the fastest way around a corner, it makes the car far more approachable at the limit.

That said, patience was the name of the game around tighter corners—especially Turn 6 (Danny’s Lesson), which is arguably the sharpest hairpin at High Plains. The front end pushed hard there, and in my second session, I came in intentionally hot to find the edge. Oh, I found it alright. The car plowed straight over the curb and into the dirt. But hey—you can’t know the limit until you exceed it, right?

With the factory open differential, getting the rear to rotate on throttle just wasn’t happening. No matter how much gas I gave it, the car stayed planted up front and begged for more grip/more rear rotation. The car is currently running a Bilstein B12 cup kit, which pairs Eibach springs with Bilstein B8 shocks. For street use, I’d recommend this setup to almost anyone. It’s quiet, affordable, durable, and gives the car a slightly sportier feel without punishing your spine. The downside? The Eibach springs have similar rates to the OEM Sport package springs, and the Bilsteins aren’t adjustable. Translation: body roll—and plenty of it.

While it doesn't roll as much as, say, my ND2 Miata, the body roll on track was noticeable and, at times, disconcerting (especially in the higher speed sections). These spring and damping rates are great for spirited street driving, but when you're pushing to 10/10ths, they just don’t inspire the kind of confidence you want. At around 8/10ths on a twisty canyon road, the setup is a good time—but on track, where seconds matter, it’s clearly the limiting factor.

The car is still running OEM front and rear sway bars. I’ve considered upgrading, but the stock front bar is already fairly stout, and a stiffer front bar would likely worsen the existing understeer. The smarter move is a proper set of motorsport-oriented coilovers, with the possibility of adding mild, adjustable sway bars later to fine-tune balance.

Late braking on the back straight revealed another weak point: the car got a bit squirrely under heavy, high-speed braking. It’s possible I was simply pushing into ABS rather than threshold braking—in fact, that’s the most likely explanation—but I also wouldn’t rule out the soft suspension and open diff playing a part. Neither setup is particularly confidence-inspiring under max effort conditions. I have a set of Whiteline rear subframe bushing inserts which help to keep the rear subframe from jiggling around as much as it does in stock form, but there's also a possibility that the soft rear subframe bushings might be coming into play here. It might not be a bad idea to just drop the rear subframe and install a proper set of [aluminum?] bushings.

If this all sounds like a harsh track review, that’s because it is—and it needs to be. To get faster, I have to be brutally honest about where the car is falling short and what needs to change. As I mentioned earlier, I’m limited in how much power I can add or weight I can remove due to class rules—but there are still a few class-legal areas that could make a big difference:

• Coilovers

I’m fairly certain I was the only competitor not running proper coilovers. A good set should significantly improve driver confidence and likely shave seconds off my current times.

• Limited-slip differential I left the eDiff enabled thinking it might help, but a mechanical LSD would make a big difference in rotation and power delivery. Again, I’m pretty sure I was the only car out there with an open diff.

• 3.73 final drive (from the automatic) In several corners at HPR, I found myself dropping into second only to have to immediately shift back to third. By the end of the day, I was just leaving it in third to avoid the awkward post-corner shift. Swapping to the 3.73 (up from the manual's stock 3.23) should offer better gearing for my home track.

• Wider wheels and tires I’m currently running 235/40/17 RT660+ tires on Apex 17x8.5 wheels—the widest I could fit with the Bilstein B12's spring perches. Every other car I saw in class was running at least 245s on wider wheels. Moving to a motorsport coilover setup would free up space for a wider setup (likely a 17x9 wheel)—potentially 245 or 255s—and also open the door to faster tire options.

All in all, I had a blast at yesterday’s event. I didn’t view the lack of a podium finish as a loss—I saw the car’s bulletproof reliability as a big win. More importantly, the event clearly showed me where the car is lacking and what changes would make the biggest difference. Once my wallet recovers from its recent beating, I know exactly what’s coming next—and I can’t wait to feel the difference on track. It's been a while since I've been this pumped up for a track build. This is going to be fun.