Mila Development Diary: Autocross 1
The first time I wrote about Mila, our ‘90s BMW 318i, M3-powered project car, I talked about how an innocent starting conversation led to a purchase. As my dad, Kev and I embark on our 3rd season with the car we decided to get a little more serious about turning Mila from a “fun car” to an autocross contender.
During the first couple of off-seasons, Mila was enrolled in a weight loss program. All motors and hardware were removed from inside the rear doors, and lightweight door cards were installed in place of the stock panels. The car came with the stereo, A/C, and trim removed, so the interior is essentially gutted at this point. Passenger and rear glass windows were swapped out with acrylic ones. The stock hood was booted in exchange for one made of carbon fiber with four corner latches, thus removing the big front hood spring and all the hinge mounting pieces. Upgraded to a manual short-shifter kit for quicker, more direct throws. The wheels are also wider (staggered with 225s in the front and 245s in the rear) and taller (increased from 15s to 16s).
Even though the three of us started to get more comfortable with Mila, we still could not get a handle on her severe desire to swap ends under power unless she was pointed dead straight. We had some spirited discussions around what should be done to the car to get her over the hump into contention. And while these conversations included the best of intentions, they lacked in follow through when it came to the suspension.
But this year is different. My dad spent a lot of time this spring tinkering around with Mila. An unexpected benefit of COVID was some newly found free time of a friend of ours, Jim, who has a great feel for setting up BMWs for the track. With Jim’s guidance, 300lb springs were replaced by 550s from Ground Control. Sleeves and spring perches were also replaced to accommodate the new springs. Adjustable sway bar links were installed, and the car was corner-weighted.
We were feeling pretty good about the car’s progress over the last couple months. Now with a pandemic-delayed autocross finally at hand, it was time to put Mila’s updates to the test.
There was a great turnout, especially in Mila’s class which included 22 entrants! I had some high hopes for finishing well. Given that this was my first speed event of the year, and that I hadn’t even driven Mila since last fall, I knew there might be some rustiness on my part. That said, I thought a top-5 finish was within reach.
My dad and I double-drove Mila with my dad taking his morning attempts first. He was getting a handle of the course direction and starting to chip away at his times. But following his 3rd attempt, I noticed that the front right wheel was wobbling badly. I feared that something serious had occurred. To my relief, and my dad’s embarrassment, he had forgotten to torque down the wheels after working on the suspension the night before. In an adrenaline-fueled remark, he barked something along the lines of I can’t f***ing believe I forgot to torque the wheels down! I’ve been doing this for 30 years and I’ve never done that before. I was just happy the fix would be quick.
Now that the wheels were properly torqued down, it was my turn at the wheel. The weather’s starting to creep into the 80s outside with full sun on the course. The tires are starting to get a little hot so we’re dropping the air pressure a bit between runs. As I get used to the course, I start pulling down some decent times. I end my last run of the morning with a 39.9. Not too bad, but still over a second off the top contenders which is a long time by autocross standards.
Jim is curious about how we’re doing, and texts us to find out how the suspension feels. My dad replies back that it seems good but we’re on new tires and have only completed the first set of runs. We would provide a more thorough update at the end of the day.
My dad starts the afternoon session’s five allotted runs and quickly breaks into the 39s too. He ends his day with a 39.69. The car is feeling good. We drop the tire pressure a little further as the afternoon temperature continues to rise. Now it’s my turn again. On my 3rd run I get down to a 39.3. The guys at the top are in the low-to-mid 38s, but I have two more runs left and think a mid-38 is possible. I decide to go for broke and really push it on my 4th run but end up getting a little tail-happy in a couple sections and get another 39.3. I decide to rein it in a bit for the last run. It feels good but I only end up improving a few hundredths of a second with a 39.25.
The winner finished with a 37.92. I finished in 9th with my dad right behind in 10th. I’m disappointed, but fairly confident that Mila was capable of a 38.5 if we could’ve put one solid run together.
As my dad, Kev and I pack up the cars for the day we realize that we hadn’t given Jim a proper update on all the work and advice he provided. Someone parked next to us is selling his car and we get to chatting. I borrow his “For Sale” sign, put it on Mila’s windshield, and text Jim a pic with no other context.
Needless to say, he was surprised. We broke down later that afternoon to let him know that we weren’t in fact selling the car but enjoyed our practical joke.
During the event I still had trouble getting the power down without the back stepping out, and there seems to be some softness in the rear, but it can be a little challenging to get a great feel for changes made to the car with less than 7.5 minutes of total drive time. Next stop, Blackhawk Farms on July 15th for an HPDE to really stretch her legs. We should hopefully get a couple hours of track time to play around and assess her progress. If the weather is decent, Mila should be able to lap Blackhawk in 1:22, ideally less. We’re going to hook up the GoPro with the TrackAddict app and post some video with our progress next week…stay tuned!