NASCAR is venturing into unknown territory this weekend. For the first time in history, an active U.S. military base will host a national NASCAR race as the sport heads to Naval Base Coronado. Although the historic location has garnered media attention, drivers are immediately preoccupied with something very different. It’s the harsh 3.4-mile street course with 16 turns that is full of bumps, surface transitions, elevation changes, and little opportunity for error. Furthermore, one Trackhouse insider claims that the most difficult obstacles could even appear as soon as the green flag is dropped.

The first three turns could decide the NASCAR San Diego weekend

“Yeah, this is a tricky corner [turn 1], high commitment, and again no error. So you see it’s on the concrete or airfield as you turn in very bumpy. And then on exit, there’s two types of seal changes. You can see where it goes from dark to light, and seeing it last week it’s like they put their patch in to try and make it smoother. But it’s still very rough there, and pretty much instantly as you exit that corner, it’s a really steep downhill.”

That was Shane van Gisbergen giving former crew chief and commentator Steve Letarte a sneak peek at what may turn out to be the San Diego street course’s most talked-about segment. Surprisingly, they didn’t even go past Turn 3. Right after the Ellyson Start/Finish Line, the lap starts with a fast right-hand bend. Turn 1 doesn’t seem particularly dramatic on paper.

However, in actuality, cars arrive on uneven concrete that has been poured across an active military airfield, navigate the many pavement seal changes, and then start to descend nearly immediately. Shane van Gisbergen pointed out that surface patches have already been added to smooth the transition areas, but the track still remains rough.

Add in the downhill profile and the fact that cars may briefly unload over the crest, and drivers are entering one of the most unpredictable openings NASCAR has built in years. Then Letarte asked: “So the next two corners are kind of 90-degree lefthanders? Does it really just come down to like track texture and bumps that are gonna make the two corners look different?”

Shane van Gisbergen’s answer wasn’t about the corner’s shape but about what happens after. “Yeah, this is when you get in the corner, it looks quite smooth. But again, you can see it narrows so much on exit so that the wall on the outside comes at you so quickly, and then into turn two. So it stays. On restarts you might be three or four wide into this corner, but you’re exiting into a place you can only really be two wide, so that’s going to be that’s going be tough to sort out for us.”

That’s where another concern begins. The exit of Turn 1 feeds directly into Turns 2 and 3, two fast 90-degree left-handers running along the edge of San Diego Bay. The entry zones are wide and inviting, but the exits rapidly tighten. They go from being four-wide to just two-wide.

That naturally creates severe communication blind spots. Spotters may call drivers into openings that disappear just seconds later. Crew chiefs will need to predict not just pace but positioning. And on restarts, where cars naturally spread out, the first three turns could turn from eight lanes of opportunity into a two-lane bottleneck. We saw something similar in last year’s Chicago race, where Carson Hocevar sparked a 7-car wreck at a blind spot for the drivers inside the Turn 11 curve.

NASCAR San Diego may have 16 turns. However, according to Shane van Gisbergen and Steve Letarte’s preview, the race could be won (or wrecked) before drivers even reach Turn 4. And we have just hours left to find out exactly that!