[CLICK HERE TO SEE VIDEO OF THE 370Z ON TRACK.]
350Z Track Test
The first problem we noticed," laughs Costa, "was that the 350 would experience fuel starvation at any less than a 70-percent-full tank. Back on their game, the crew began the process of dialing in the car: one or two laps out, followed by pit stops for adjustments. Tire pressure was monitored and adjusted, brake and engine temps were logged, and tweaks to various parts of the suspension were made to find each one's "sweet spot".
"Once we got the car running strong, the brakes started acting up," notes Costa. The particular rotors and pads they were using were designed as a more aggressive, street-friendly upgrade-not for hard track use. "At first, we noticed the brakes building a layer of dust and gas between the rotors and pads [called the fireband] that the rotors' cross-drills and slots weren't able to scavenge," explains Costa. "So, we knew we needed to notch the pads to help, but that would decreased overall surface area, which would decrease braking performance. We switched to more aggressive Friction 01 pads, notched them, and went back out," he continues. "And that worked great for a few laps, until we began cracking rotors." Metal expands as it's heated, and one-piece cast rotors, like the ones Dai's 350z was using, leave little room for expansion. "We're hoping to run AP's full competition brakes next year," he says, "which use larger calipers and two-piece, floating rotors designed for extreme heat."
Dai and Costa's second major setback was also due to heat. "Oil temperatures were pretty high all over the car," explains Costa. "Engine oil and differential oil were highest, but transmission oil was up there, too." The solution? "We had no time or parts to rig up coolers, so we had to keep our sessions down to two hard laps at a time," he explains. "But with the basic engine oil, transmission and diff cooler, there shouldn't be any problems." Dai, Costa, and the GTI crew managed a best time of 2:04.872 for the event, and in separate conversations, all estimate the car could break the two-minute mark with minor upgrades in the future. "Yes, there's room for improvement, but we're pretty happy," concludes Costa. "That was the car's first time out, a lot of the mods had to be completed super last-minute, and we overcame tons of problems."
Costa's sentiment underscores each teams' evaluations of their cars' on-track performance. "It seems like Nissan really listened to what owners of past Zs had to say about their cars, before designing the 370," comments Tyler. "On paper, the car is much better than the latest 350 . . . I think it definitely has potential." That's not to say he's exactly thrilled with the new car. "But the electronics kill it. It's almost like Nissan built the car too well, and then decided along the way to dumb it down with ABS and traction control to keep people from driving them too hard. At the very least, disabling these features should've been made a practical option." And then there's the mysterious heating issue. Says Mike Chung of Greddy, "When we talked with our Japan offices about turbocharging the 370Z, that was the one area we were warned about. We have new products in the works that will help, but all Z owners should be aware of the problem, even though we hear Nissan is quietly working on a solution for next year's model."
The GT Channel 350Z crew is also looking forward: "With better brakes and some aero, like a front lip splitter and canards, maybe a rear diffuser and dialing in the wing, we could've lost a few more seconds," comments Kojima. "Costa says he could drop even more weight from the chassis, and I could really improve the suspension by modifying the pick-up points." HKS asked that the crew use the car's stock catalytic converters and not change the supercharger system's stock boost level during Super Lap Battle competition, to test the capabilities of the off-the-shelf supercharger. "If we would've replaced the cats with test pipes and had a chance to re-tune-maybe increase boost with a custom pulley-it would've made a big difference," Kojima speculates.