The 8,970 Hours of the Nurburgring

Rotek Racing BMW Z4 Exiting the Kleine Karussell Image Courtesy of Frozenspeed

Rotek Racing BMW Z4 Exiting the Kleine Karussell
Image Courtesy of Frozenspeed

My journey to the 2016 ADAC Zurich Nurburgring 24-Hour race started with a catastrophic engine failure in my Rotek Racing Audi TT-RS six hours into the 2015 race. I watched our lead evaporate while juggling a flood of emotions and hoping, in vain, the car could return to battle. Disappointment took hold when the reality of a ventilated engine block sunk in, but I felt solace in knowing I would be back. I had swallowed the hook. The 2016 race was only 8,970 hours away.

First run in 1970, the Nurburgring 24-Hour is one of motorsports’ greatest challenges; a throwback to when racing was dangerous and sex was safe. The 25-kilometer circuit used for the Nurburgring 24-Hour winds around the modern Grand Prix track before heading out onto the 180-plus corners of the daunting Nordschleife. Runoff? Best not to think about it, but suffice it to say, there is not enough runoff in all of Germany if you get it wrong while flat in sixth gear, in the rain, through Schwedenkreuz or Fuchsröhre or Tiergarten or …

Pflanzgarten in the Mist Image Courtesy of Frozenspeed

Pflanzgarten in the Mist.
Image Courtesy of Frozenspeed

GT3 entries from Audi, BMW, Mercedes, Nissan, Bentley, Aston Martin, Lamborghini, and Porsche fight for overall glory at speeds in excess of 260 km/h while airborne multiple times per lap. Add more than 150 entries of vastly differing speeds to the constantly changing weather and you have a recipe for greatness, or a potential disaster of epic proportions, depending on your point of view.

My planning for the 2016 Nurburgring 24-Hour started the instant Audi’s piston disintegrated. Okay, that is a lie. I started planning after spending a few hours watching from the safer side of the guardrail on an alcohol-fueled march through the Eifel with my Rotek Racing crew. The 24 Hour is a social phenomenon. Upwards of 200,000 people pack the hillsides for days consuming prodigious amounts of beer and German sausage. Not sure how much of the race they actually see, but when on track, I try to put on a good show, or at least not screw up, in the major spectator areas. The Audi’s demise enabled me to see the race from the fans’ perspective. Glad I did.

After 32 years in motorsports, I know pulling together a winning effort happens in the offseason. I definitely had the right team in Rotek Racing. Rotek knows how to win endurance races, having taken the overall win in the 2013 25 Hours of Thunderhill. The Rotek TT-RS is a rocket on the track, but proved to be too fragile for the Nurburgring. Competing for the overall win against the factories in SP9 (GT3 specification cars) is a tall order, so my goal was to go for a class win.

Fortunately, Rotek keeps a V5 (production-based) BMW Z4 in its stable and it is a fantastic car to drive. In a world of dual clutch transmissions, traction control, and carbon fiber, the Z4 harkens back to when drivers had to know how to juggle three pedals, two feet, an H-pattern gearbox, a steering wheel, and two hands to execute a heal-toe downshift. I have been practicing since 1984.

Last September, I flew back to Germany for a VLN race with my friend and IMSA competitor, Jon Miller. I had driven the Z4 previously, but wanted to confirm it would be competitive in the 24-Hour and hook Jon on racing at the Nurburgring in the process. Jon and I were competitive until we tried to stretch the fuel to nine laps and came up short. Rotek got me some fuel out on track and we brought the Z4 home sixth.

“Today was completely overwhelming and incredibly humbling,” commented Jon after the Nurburgring had worked its magic. “This track is unlike anything else. Your ears pop from over 1,000 feet of elevation change per lap. You’re airborne in fifth and sixth gear a few times per lap. I’m driving a relatively slow car and cooperation here is key. The GT3 cars are on another planet, speed-wise.”

Working Traffic in Practice Image Courtesy of Frozenspeed

Working Traffic in Practice.
Image Courtesy of Frozenspeed

I kept warm over the winter analyzing data from the VLN race to prepare for the 24-Hour qualifying race in April. One way to picture the Nurburgring is to think of it as six racetracks connected nose-to-tail. Repetition is the problem. A 15-minute practice at Lime Rock gets you 15 laps. Fifteen minutes at the Nurburgring gets you one, maybe two. The data showed I was over-slowing to use third gear in places where running fourth would preserve momentum.

Armed with this information, I found five seconds per lap and was confident there was more on a clean lap. Clean laps are hard to come by at the Nurburgring, and it gets even harder when you factor in the weather. I had rain, snow, hail and sun in my first stint. I identified a need to improve the Z4’s front lateral grip and rear traction, but overall I was pleased.

The Nurburgring is the ultimate challenge, a pilgrimage to some and a rite-of-passage to others. There is no easing into a lap. -David Thilenius

The Nurburgring is the ultimate challenge, a pilgrimage to some and a rite-of-passage to others. There is no easing into a lap. Sure, the Grand Prix circuit is wide with runoff, but fail to execute a pass and your next opportunity is kilometers away. Make it through Hatzenbach and Flugplatz and you are on your way to Schwedenkreuz where the crest pitches the car airborne, kicking the rear of the car higher than the front. Jump, land, bounce, brake, take fifth gear, and back to throttle for the ultra-fast left. Stay out of the gravel at Aremberg and you are on a gravity-injected 11 percent downhill run into Fuchsröhre, followed immediately by a 10 percent uphill run into Adenauer Forst.

The compression in Fuchsröhre can knock the wind out of you. I hold my breath, especially in the wet. The run down the mountain to Breidscheid is mostly straightforward. However, be aware! Spectators congregate where drivers make mistakes and there is a lot of fresh guardrail in Adenauer Forst and Wehrseifen.

From Breidscheid, the long climb to Hohe Acht takes you through a nearly flat out kink unofficially known as Angst or Mut Kurve. The German translates into “anxiety” and “courage.” I can identify with those terms. Next up, the concrete banking in Karussell pounds the car onto the bump stops, rattles your vision and compresses the driver so the belts feel loose.

From Karussell, things get interesting. Dodge the curbs into Hohe Acht, curb hop through Wippermann like Hans Stuck, keep it clean for the fans and cameras in Brünnchen, and you will arrive at Pflanzgarten. Pflanzgarten 1 requires braking before and after flight for the double apex right leading to the second jump. The easy way over Pflanzgarten 2 is to take the crest square; the fast way is to take the crest diagonally landing on the right front.

The track rolls and pitches through the Bellof-S for the next kilometer and you are sure you will do it flat, next time. Survive Schwalbenschwanz and Galgenkopf and you finally get to rest and check the gauges on Döttinger Höhe while GT3 cars draft by at more than 260 km/h. The final challenge is the downhill run into Tiergarten and braking for the Hohenrain chicane. Get it wrong over the bumps or misjudge your braking and the concrete walls await your arrival. That is one lap.  A full stint is eight laps.

Leaving the Pits During Practice Image Courtesy of Frozenspeed

Leaving the Pits During Practice.
Image Courtesy of Frozenspeed

In the run-up to the 2016 24-Hour, the final details fell into place. Jon completed his licensing requirements and joined Robb Holland and I on the entry. JRZ Suspension Engineering developed new dampers to address our handling issues. Additionally, my long-time race engineer Marcos DeLeon joined the team to call race strategy. With our driving line-up, Marcos on the pit wall and crew chief Peter Lorg leading the Rotek Racing crew, we had the right team.

Unfortunately, the weather forecast for the race somewhat tempered my enthusiasm. The “Green Hell” is challenging enough without the notoriously fickle weather in the Eifel threatening rain the entire weekend. I rolled into Nurburg not knowing what the next four days would bring. After an easy day in the paddock, the drivers retired to the Pistenklause, a must-do on any visit to the Nurburgring. The food is good and racing memorabilia covers the walls. The sense of history is palatable, overwhelming and yet inclusive. Sitting there, I felt humbled to be part of a fraternity of drivers racing on the Nordschleife.

Preparing for Night Qualifying Image Courtesy of Frozenspeed

Preparing for Night Qualifying.
Image Courtesy of Frozenspeed

Weather predictions dominated my thoughts when I rolled out for Thursday’s practice. I took advantage of the dry track to place the Z4 P1 with a lap of 10:10.728. P1 is great, but nobody wins practice. Our JRZ dampers greatly improved rear traction, but the persistent understeer called for more adjustment. Later, night qualifying started under threatening skies. The forecast called for rain overnight and through final qualifying Friday morning, so I knew the grid would be set in night qualifying.

I revel in the pressure and focus of qualifying. When Marcos asked for feedback on the handling, I simply replied, “I’m just qualifying right now.” There would be time for feedback later. Dodging traffic and scattered rain showers, I laid down a 10:13.546, good enough for P2 before the rain came down in earnest. Jon and Robb completed the session, each logging their required night laps.

Changing to Rains Image Courtesy of Frozenspeed

Changing to Rains.
Image Courtesy of Frozenspeed

Friday’s final qualifying started on a drying track. Determining where there was grip was easy. If the track was in the shade, it was wet. I ran one lap on our Yokohama rain tires before changing to slicks and, foolishly, tried for a quick time. I vastly misjudged the grip in the shady Fuchsröhre section and chased the rear of the car most of the way up the hill to Adenauer Forst before regaining complete control. Getting my heart rate under control took a bit longer. Jon and Robb got some running and, as expected, the times set in night qualifying set the grid.

The weather continued to tease and race day dawned sunny. Pre-grid at the Nurburgring 24-Hour is a wonderful experience. Fans come out in droves, packing the grid, stands, and hillsides around the track while the drivers engage in lighthearted banter to mask the tension. The nervousness I feel on the grid is why I race. In those moments before the engines start, when the grid is clear, I know I am alive.

On the Grid for Children's Tumor Foundation Image Courtesy of Frozenspeed

On the Grid for Children’s Tumor Foundation.
Image Courtesy of Frozenspeed

The nervousness I feel on the grid is why I race. In those moments before the engines start, when the grid is clear, I know I am alive. -David Thilenius

I took the green second in V5, 112th of 153 starters. On the Grand Prix circuit, I made some aggressive moves and had light contact in traffic before setting out on the Nordschleife.  The Rotek Z4 was quick and gaining on the V5 leader when rain hit Adenauer Forst. Most of the track was dry, so my instinct was to stay on slicks. Marcos knew better than to trust my instincts and called me in for rain tires. It was a fortuitous decision. Moments after pitting, the rain turned to hail — 25 cars went off and the red flag stopped the race.

After a three-hour break, the field was re-gridded based on the last green flag lap. Heavy rain and fog kept the field behind the pace car for three laps. As I took the green for the second time, Marcos counseled, “No low percentage moves.” The irony of the statement gave me a chuckle. Everything about driving the Nurburgring in rain, fog, and darkness with 150 other raging egomaniacs seemed “low percentage” to me!

Restarting in the Rain Image courtesy of Frozenspeed

Restarting in the Rain.
Image courtesy of Frozenspeed

Spray reduced my visibility to less than a car length. I searched through the fog for the glimpse of a taillight and hoped those behind me were doing the same. The handling of the car in heavy wet conditions was good, but when the rain stopped, the car developed some snap-oversteer on corner entry. I am not a fan of snap-oversteer and still do not understand the physics of the dramatic change in handling.

Fighting Oversteer in the Rain Image Courtesy of Frozenspeed

Fighting Oversteer in the Rain
Image Courtesy of Frozenspeed

Turns out, Jon is not a fan of snap-oversteer either. Jon took over when I pitted for fuel and held on brilliantly until a dry line developed. I ate, hydrated and tried to sleep in the transporter. Switching off after a stint is nearly impossible. Twilight sleep was all I could manage until roused by a radio transmission from Jon saying a GT3 car had pushed him into the barriers in Pflanzgarten. Pflanzgarten is a serious place for a shunt. We were victims of an impatient and ill-advised move by an AMG driver who should have known better. The track marshals towed Jon out of harm’s way and the Rotek Racing crew leapt into action repairing the front suspension, replacing a half shaft and re-aligning the car in record time.

After the repair, Robb took over from Jon for his first stint. Many laps down, losing motivation would have been easy, but the crew had done their work and it was time for the drivers to do ours. Robb turned in a solid stint but reported an intermittent vibration in the left front. The team checked the suspension when Robb pitted for fuel and driver change but were unable to find anything amiss. I drove a double stint into the sunrise while Robb and Jon slept. The vibration in the left front was noticeable but did not hurt my pace. Unfortunately, in the second half of my stint, the vibration got worse.

Karussell at Night Image Courtesy of Frozenspeed

Karussell at Night.
Image Courtesy of Frozenspeed

I tried to convince myself the change was only in my sleep-deprived head, but my usually dormant self-preservation instinct inspired me to pit. Further inspection did not reveal anything obvious. We suspected the intermittent nature of the vibration was the result of damage to the damper from the earlier contact. On my stop, Jon took over to run a double stint. Ninety minutes later and 17 hours into the race, I awoke to Jon’s voice on the radio reporting the left front suspension had collapsed. Familiar disappointment settled in with the realization even if we repaired the car, we would not record enough laps to classify as a finisher. Retirement was our only option.

For the second time, I leave Germany with unfinished business at the Nurburgring 24-Hour. I am pleased with Rotek Racing and the support Thilenius Group and our program gives to Children’s Tumor Foundation, and its goal to end NF.

To contribute to CTF with a donation, visit the website at Rotek Racing will be back in 2017. I will be back in 2017. The clock is ticking. There are only 8,970 hours until the start of the 2017 Nurburgring 24-Hour.

About the author

David Thilenius

Growing up in Alaska, David Thilenius was not on a path towards the automotive industry, but that changed in 1983 when he saw video from a Porsche 956 at LeMans. Within two years, David attended racing school, enrolled in college, and began working for GM. A BSME led to a career in vehicle dynamics with GM, Toyota, Hyundai, and his own consulting firm. Engineering pays the bills, but driving is David’s passion. From formula cars, David moved into endurance racing, winning an IMSA drivers’ championship in 2010. He currently races the Nurburgring and writes about his adventures.
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