Brian Lock began building his Valkyrie Autosport 370Z racecar three years ago with the unwritten goal of beating a Porsche GT3 Cup Car. While the Porsche is technically a production car, the vast resources of the German powerhouse and the racing success it’s had put the Cup Car in its own category, nearly. Lock knew that with the Porsche making near-500 horsepower with its 4.0-liter racing engine, he would never be able to keep up with a roadcar-sourced block. To compensate he opted to use more tire and a larger fuel tank to try and gain an edge with pitstop strategy.
It turns out, his car was much faster than anticipated.
Lock’s last weekend at Willow Springs started tensely. With a bevy of new parts on his racecar, he was naturally worried about them lasting the length of the event. Initial testing of the car showed promising results but the true test would come with pushing the car to its limit for three hours. Sweating quietly in P2 with the Porsche GT3 sitting to his right on pole, Lock knew this was his chance to see what the 370Z could do against a car that had decades of endurance success.
Among the new parts added to the car is a Quaife six-speed sequential. Not only does this better harness the 360 wheel horsepower on tap, but it auto-blips on the downshift, which allows Lock and his team to left-foot brake. By replacing the stock transmission with a sequential, the 370Z becomes competitive with factory-built racing stars, like the GT3 and the Audi R8, which both come with a sequential gearboxes.
In order to match the race-bred handling of the Porsche, Lock has developed the car with larger, stickier Hoosier slicks, JRZ suspension, an Aeromotions wing, and SPL suspension links. This combination clearly worked well on the 370Z, as evident in the race when Lock was making up time on the Porsche in the corners. Being the first weekend out, the car showed amazing potential, but there is still some work to be done to correct a low speed traction issue. Compared to the Porsche, the Nissan can’t quite drive off the corner with the same ferocity, but then again, what car can?
It’s that shortcoming that made the overtaking process all the more challenging for Lock and company. Negotiating late-braking maneuvers came easily with left-foot braking and the wider rubber, but when Lock was forced onto the inside in low-speed corners, keeping that 3.7-liter V6 from smoking the rear tires took some restraint and a very smooth, deliberate throttle application. When dicing and pushed off-line onto the marbles, it’s quite easy to loop the car with a heated prod of the loud pedal, especially when the engine pulls as hard as this one does.
The motor’s low-end torque is complemented by a surging top end, thanks to a set of Jim Wolf Cams, heads from the VQ35HR, and a custom header setup from PPE. This was then all brought together and optimized by the tuning at FFTec Motorsports. Considering how this junkyard block powered something that could nip at the heels of the Porsche and its $30,000, purebred racing motor, it’s economical if nothing else.
Incredibly, the engine made enough grunt to keep the GT3 at bay lap after lap, though on the front straight, the power advantage of the Porsche was noticeable. In Turn 9, leading onto the front straight, Lock would have to wring the neck of the car to get a good drive off the corner so the Porsche’s power couldn’t quite make up the difference. Naturally, Lock’s superior driving ability ensured that happened some of the time, but when the Porsche’s driver did get the power down well, there was no contest, he would have a significant gap on the Nissan by the braking zone into Turn 1. This is first seen at 3:38, and more impressively again at 11:06, where the punch and power of the Porsche is on full display.
However, even when passed, Lock found areas in which he could make up some distance. Most notably in Turn 3, where the off-camber changes favor the driver with the more sensitive inputs. However, it was traffic that aided Lock and his team the most.
Coming upon a backmarker, the Porsche’s driver shows a little hesitancy when trying to overtake. Despite a significant lead, Lock claws back, and thanks to better racecraft, regains the lead at 5:56, and later at 18:04, with opportunistic moves that might’ve looked less methodical than they were.
“It’s really important to be decisive when overtaking”, remarks Lock, “I want to make sure he sees me coming and isn’t going to move across at the last moment, so I presented myself early and made sure he knew I meant it.” Nevertheless, a mild hesitation is noticeable during the second overtake: this is Lock ensuring that he’s not going to clash with the Civic, which has its mirrors full with two jostling racecars.
“I telegraphed my move and when I saw he wasn’t moving over any further, dived in and braked as late as I could,” he notes. Keep in mind, Lock pulled this planned stunt off on a dustier part of the circuit, and needed some cadence braking to keep the three from turning their meticulously-prepared racecars into a half-million dollar pile of scrap. It takes levelheadedness to make those sorts of moves with such a narrow margin for error.
With some modesty, Lock admits to the GT3 being slightly quicker than their car. With a professional driver in the Porsche’s hot seat, it’s unlikely the 370Z would’ve been able to match the straight-line speed and low-speed traction. As the three-hour race progressed and a quicker driver got behind the Porsche, the difference was obvious. With a little more power and chassis tuning, the 370z it should be competitive with a pro-driven GT3 Cup.
Yet, by the end of the event, Lock and his co-drivers managed to take their 370Z to the second place on the podium, finishing just behind the Porsche. The Valkyrie 350Z backed up their 25 Hours of Thunderhill win with a first place in the E0 class. In fact, Lock and his GT cars stood at the top steps of the ES production class, and were only beaten by the Porsche and a few prototypes. Not bad for an overweight GT with a junkyard motor, eh?