A Minor BMW 128i Setup Adjustment Helped Earn Me a Podium Spot
The little BMW coupe continues to prove itself as an awesome track car.
A few weekends ago, I took part in my third track day with my BMW 128i. The day proved to be quite fruitful, as some changes to my driving and setup led to a podium finish in my first time ever competing in a time attack challenge series. More importantly, I set a new personal best lap time of 2:14.997 at the end of the day, just under a second quicker than I achieved a few years ago with my Mazda 2 with a much more focused setup.
I hadn't intended on signing up for this event, or even competing in Bimmer Challenge, a popular SoCal-based BMW time attack series. But my buddy Rob (the 128i's former owner) mentioned he'd signed up with his E92 M3—I didn't want to miss this hangout sesh. Plus, I love Buttonwillow's 13CW configuration and hadn't ripped through it in over a year, so a visit was definitely in order.
Strong Brake Pads Are a Must
One of the biggest changes to my car was the brakes. Last time I was on track at Streets of Willow, I'd forgotten to swap out my street-going Hawk HPS pads for more track-centric fare. This turned out to be a big mistake. The HPS equipment held up OK but didn't have the confidence or the repeated-lap endurance of a more aggressive compound, like the HP Plus pads that came with the 128i when I bought it. I took the time to swap to the HP Plus kit on the front axle the night before this time around, and it drastically improved the performance.
The car felt so much more confident under braking and allowed much shorter stopping distances. Braking from 103 mph to 55 mph (I could corner faster, but I'm still learning the car) for Buttonwillow's final corner, Sunset, was a breeze lap after lap, and having good modulation made for effortless weight balance. There are stronger track-centric compounds out there with even better modulation, such as the G-Loc R10s I had on my Mazda 2, but free-ninety-nine is free-ninety-nine. The Hawks only started to give up once I started to shorten my already very short stopping distances later in each session, which is a lot to ask of any pad compound. I'm thinking some non-pad upgrades, like ducting air to help keep the pads in the temperature sweet spot, could be in the cards as a future mod.
I Didn't Bother Doing Any Shock Tuning
Originally, I thought I'd try my hand at doing some minor shock tuning, because my Koni Yellow dampers have adjustable rebound. Rebound is the speed at which the shock bounces back to full travel after a bump. All four of mine are set to full soft, therefore the 128i rides comfortably in all scenarios, but body roll is definitely magnified at track speeds.
However, this proved to be a good setup for Buttonwillow, especially considering that the best line to take is over its generous amount of curbing. This includes jumping the inside curb at Bus Stop, in the middle of the circuit, which then ensures good entry speed into Riverside, which is the following complex of long sweepers. Keeping the dampers comfortable meant curb work didn't upset the chassis in any way, they just soaked it all up.
The car felt generally neutral, however I felt that I was missing out on some rotation in some sections when I started to up the pace. This happened at Sunrise, On Ramp, and Sweeper, which are three crucial corners. So, I shall heed the advice given by commenters in my first track blog and tighten the front and rear dampers, but the rears more so to help the rear end rotate around.
Body roll wasn't bad, and I stayed planted in my M Sport seat thanks to having a street-legal Schroth QuickFit harness, but slightly less roll would be nice. Still, for Koni Yellows and very street-friendly Eibach Pro-Kit springs, the 128's on-track qualities were quite good.
It Felt Great to Be Out There
One of the greatest chapters in American touring car racing was the early 2010s Grand-Am, now International Motorsport Sports Association (IMSA), Continental Tire Sports Car Challenge (CTSCC) series. This is mainly due to all its epic naturally aspirated front-wheel-drive-versus-rear-wheel-drive action on track. Like the eighth- and ninth-generation Honda Civic Si versus the BMW 128i, for example.
My attendance at this track day in my own street-going BMW 128i turned out to be a sort of informal CTSCC tribute, as I found myself hangin' with a skillfully driven eighth-gen Si through Buttonwillow Raceway Park's fun 3.1-mile circuit for a couple laps. I included some of that in the above-linked video—this cat was great fun to follow and definitely kept me motivated to drive faster.
I Achieved a New Personal Best and Won Some Hardware
It felt good to reset my personal best lap in a car I'm still getting the hang of, though it isn't quite as focused as my old Mazda 2. The 2 had a bunch of interior components removed, a lightweight racing seat, better tires, and I set the time during early winter when Buttonwillow is blessed with cool ambient temperatures. This time in the 1er, I was on far worse tires mounted up to a less familiar chassis with a 105-degree ambient temperature. I'm excited to get more and more acquainted with the chassis, eventually throw better tires on, make some adjustments, and hopefully drop that time a few more seconds in the late fall or early winter. I'd be ecstatic over a sub-2:10.XXX.
Earlier in the day, a 2:15.996 lap I set was good enough for third place in Bimmer Challenge's B4 Class. I believe the cutoff for lap times was the midday break for lunch, as usually most people don't drop any more time due to the high track and ambient temperatures thereafter. In fact, many people leave after lunch due to the draconian Central Valley heat. However, there's a big caveat to my finish: Because it was a blazingly hot Summer day, a lot of the series' heavy hitters who normally duke it out in B4 weren't in attendance. Still, it was rad to win a trophy, which I haven't done since, like, second grade softball.
All in all, it was an excellent visit to the track. I was also stoked to offer some insight and encouragement to Rob, as well—he dropped his personal best time by more than seven seconds! I'm glad to be making progress, and hopefully some brake work, fiddling around with some coding, a fresh alignment after driving over curbs all day, and some light damper tuning will yield more success during my next visit. Hopefully, it's a tad cooler outside, too, as driving on track in 105-degree heat isn't the most comfortable activity.
Read More About This BMW 128i
- A Steering Wheel Spacer Transformed My BMW 128i’s Driving Experience
- My First BMW 128i Wrenching Experience Went Strangely Well
- How I’m Setting Up My BMW 128i for the Track
- My BMW 128i Really Woke Up With an Aftermarket Intake and Exhaust
- BMW 128i Spring and Damper Upgrade: What I Learned and Recommend
- Here’s How My BMW 128i Performed on the Dyno With an Intake and Exhaust