Friday my brother Scott and I took very different routes to Willow Springs raceway yet arrived within 10 minutes of each other, even though I took I-15, the route that everyone uses on Fridays to head to Vegas or skiing, plugging up the freeway. We both arrived about 4 pm which allowed time to set up everything, as night falls quickly this time of year. At the same time, temperatures drop fast in the desert, so I brought along a propane heater intended for construction sites – it worked great, with the 20-lb bottle lasting two nights and two mornings. In addition, some years back I bought a highly-rated sleeping bag, wondering if was worth it. It worked awesome even on the morning with ice. It’s amazing how well a 2-lb sleeping bag can work.
Saturday morning we were up at dawn, eating scrambled eggs, sausage, apples, and hot chocolate – no coffee on race days. Driver’s meeting at 7:30, then Scott headed out in his group which allowed passing anywhere in the straights and with point-bys in the turns. Not wanting to get myself in trouble I signed up for the other group, which allows passing only in the straights with a point-by, but no passing in the corners. I say “not getting in trouble” because even though Midlana has been done for several years, I’ve never had a safe environment where it could be pushed to find out what it would do at high speed.
Next it was my turn and everything went fine, I did a lot of passing and no one passed me. When pointed by, well, it was as if they put their brakes on. I should have run in Scott’s group because a few people either didn’t see me or just decided they weren’t going to move over – I’m not sure which is worse. Whatever issues Midlana might have, sufficient power isn’t one of them. I even caught up to a really nice Acura NSX, a car which I’ve always liked; I guess short of owning one, catching one on the track gets pretty close. Over the day I gradually built up speed, getting down to 1:38, aware though that Willow is famous for its soft dirt, rocks, ruts, and embankments off the paved course.
The datalogs showed that speed down the back straight was about 130 and 135-140 down the front straight. One thing really cool about the AIM dash was how seamlessly it timed laps after the track map was loaded into it. It was one of those rare moments where a complicated product “just worked”, so I have to take back some of my negative points it gets due to its poor CAN bus interface.
Anyhow, the excitement came after lunch when I entered the high-speed decreasing radius right Turn 8-9 combination that is famous for eating cars, and unfortunately it was my turn. Part way through Turn 8, the back end stepped out slightly, I corrected by steering slightly left, let it settle – I thought – and turned back to the right, but the slide had apparently never stopped and kept getting worse. Once it was clear I was no longer in control, I put both feet in and just held on. As you’ll see in the video, I ended up back on-course, having done a full 360 spin. Once I realized where I was I quickly got going for fear that someone might not see me. Even though there’s good visibility, the thought of a 100 mph car coming through was a little scary.
It was a good thing that I came straight in after the off. In three wheels, small rocks had become lodged between the tire and wheel, allowing the tires to rapidly lose air. Within about 15 minutes, three were flat, so a trip to the track tire shop was worth the expense, otherwise it meant removing all four tires and heading into town to find a tire shop.
Thinking about what happened, plus asking around, I came up with the following:
1. I may have contributed to the spin by doing the classic “Porsche 911 reverse parking maneuver”, where when the back of a mid-engine car steps out, the driver lifts off the gas. You can usually get away with doing so in a front-engine car, but in a tail-heavy car it can make the situation worse. However, knowing what to do is one thing, doing it is another; it’s very counter intuitive to keep your foot down when things start to go wrong.
2. It was suggested that I may have helped the slide develop by first making a small correction and then turning in again, which may have caused the back to break loose because the small correction increased lateral motion and momentum, then abruptly halting it at the front with steering. I’ve watched the clip a dozen times and I’m still not sure.
3. My tires are literally about half as sticky as my brother’s (they’re supposedly the same compound) and our cars weigh about the same. Turns out that my tires were manufactured six years ago(!), so maybe a big part of this is that they’re old and the compound has hardened.
4. Aero lift may have caused the rear of the car to become light, making an oversteer condition more likely and being less able to control it. This seems unlikely since there was no wind.
5. A previous car may have dropped oil or coolant, or kicked sand onto the track. Also seems unlikely.
6. Everyone complained about the bumps in the track in that area, so that didn’t help.
7. Not enough rear camber, probably, which is currently at -1.0 degree
8. Not enough rear tire pressure, maybe, which is currently 16 psi cold (though tire wear was even).
9. Possibly need a front anti-roll bar – but I consider it the last thing to do; bars lower traction at the end that’s working better.
10. Some combination of #1-9.
Other interesting tidbits:
– The days were cool, around 18 C
– Oil temp peaked at 90 C (194 F)
– Coolant stayed at 80-85 C (about 185 F)
– Midlana used roughly 5 gallons of ethanol per 20-minute session; my brother used about the same amount of gas.
– The ECU datalogs showed that Midlana was rarely at full throttle. There are only three areas where it’s foot-to-the-floor; the rest of the time was spent partial-throttle managing anything that wasn’t a straightaway.
The entire track was run using only 4th and 5th. In hindsight, I gave up time by not downshifting to 3rd for the upper loop of the track. That area of the track has a lower risk of damage since it’s the slowest section, but I was lazy, thinking that it wasn’t worth the bother – maybe I was wrong.
On Sunday, four more sessions were scheduled, but due to the time needed to pack up, the 3.5-hour drive home, and returning the trailer to U-Haul before they closed, we ran just the first session and called it a day. Not surprisingly I went slower than on Saturday due to being spooked by my off; the session was instead spent practicing proper lines through the turns and staying behind slower cars to study their lines. (I thought it was funny that just loafing around the track during the cool-off lap produced a 2:01, which was faster than some cars get when trying hard.
Lastly, my brother and I were extremely impressed by a class of cars referred to as “Super Miata.” It’s a bit pretentious since the mods are very slight, consisting of engine intake, exhaust, and ECU, which results in maybe 140 hp. Tires are limited to 200 wear index. I ran a 1:38, my brother ran a 1:29, and the fastest of those Miatas turns a 1:34 – very humbling. They claimed to corner at 1.7-1.8 G, which seems almost impossible (videos online seem to support 1.2-1.4G) That’s about the only way they can get such a fast lap time in a 140 hp car – you just never brake. No, I don’t plan to sell Midlana and buy a Miata.
The GoPro was once again a disappointment; I recorded four sessions yet it contained six when it was downloaded. It just decides on its own when to start and stop recording. Fortunately it was running when I had my off and interestingly it recorded the impact and spin just fine, no interrupted recording, which it seems to save for other random times. Sometimes I’d go to turn it on and it was an absolute brick – dead as a door nail, and had to fuss with it for about 10 minutes, then it would suddenly start working like nothing was ever wrong. Another thing it’s done several times is forget that it’s been configured for “one-button recording.” Digging down into the configuration menus showed that indeed, it had just forgotten how it was set up… that’s nice. I’m currently looking at alternatives.
The next event is at the Streets of Willow, a smaller tighter track next to Willow Springs. What’s really timely is that they have a large skidpad, perfect for assessing handling. I want to know what happens when the back starts coming out, can I catch it, can I control it, can I drift it controllably? When the back starts coming around, what happens if I take my foot off the gas; what happens when I keep my foot down or even increase throttle?
Years ago my brother took a BMW driving school and found what helped him the most was driving a figure-8 while trying to keep the car sideways the entire time. The purpose was to understand how a car feels while sliding in a safe environment and how to be comfortable controlling it. I want to do the same and am working with the organizers to set aside time for that, as the skidpad is normally ignored and is part of the active track. Since my tires are already half-worn and are likely in poor condition, if they end up bald at the end the weekend, that’s okay since they’ll be replaced anyway. Best of all, the whole thing will provide website visitors with something they keep pestering me for: shameless videos of “cocking about.”
Alright, enough typing. I’ll add pictures and video soon…