Wednesday, June 21, 2017

First Laps: Acura NSX GT3

SOUTH HAVEN, Michigan — The GT3 class is a huge international motor racing success, with 47 models homologated for competition since its creation in 2006, resulting in a wonderfully diverse field ranging from the logical Porsche 911 GT3 R to the refreshingly strange Bentley Continental GT3. Many series and races around the world include a GT3 class, which is regulated by the FIA. These include the IMSA WeatherTech SportsCar Championship and Pirelli World Challenge (WC) here in the U.S., the China GT Championship, Blancpain Series, and the 24 Hours of Nurburgring.

Acura is the latest automaker to join the GT3 party, homologating the NSX for the 2017 season. Honda’s luxury brand intended to have a racing version of the second-generation NSX from the get go, a fact that was noted when the NSX concept arrived at the 2012 Detroit Auto Show. Honda Racing Development (HRD) began the GT3 program in Japan, but “it was then decided to transfer it over to HPD (Honda Performance Development), because of American Honda’s extreme interest and from a brand image aspect,” noted NSX GT3 chief engineer, Lee Niffenegger.

The NSX GT3, which first turned a wheel in anger at the 2017 Rolex 24 at Daytona in January, is a much different animal than the street car, however. For starters, the all-wheel drive and hybrid systems had to be removed as GT3 rules prohibit the use of both. The engine is the same 3.5-liter, twin-turbo V-6 that’s in the road-going NSX, however. It’s virtually stock and built in the same Anna, Ohio plant.

“The (race) engines have some external machining because of relocation (in the chassis), as there’s no hybrid system,” added Niffenegger. “They also make changes to mount an alternator, as the road car doesn’t run one. The engines are then sent to HPD in California for dressing final prep, sensor kits, etc.” The road car’s gas engine develops 500 hp. In race trim, it’s bumped by 10% at best, depending on the current BoP (balance of performance) — GT3 rules allow the adjustment of weight and turbo boost to help equalize competition.

In person, the completed package is rather stunning. The Pirelli World Challenge-spec NSX GT3 I’m about to drive around Gingerman Raceway boasts huge rear wing along with impressive unpainted carbon fiber front and rear splitters. These aero details combine to give the competition version five times the downforce of the street car.

The race car features 18-inch wheels at all four corners instead of 19-inch fronts and 20-inch rears, but these come wearing 315 mm-wide front and 325 mm-wide rear Pirelli slicks. Also adorning the RealTime Racing-entered NSX GT3 is the team’s token orange paint as a highlight in areas such as the side mirrors and front dive plates. A nice touch.

WC driver Ryan Eversley talks me through the controls after I maneuver past the beefy roll cage and into the supportive seat (it’s actually a relatively easy race car to climb into). The seating position is nice and upright and offers excellent forward vision. It was refreshing to be perched in a conventional seating position. Front-engine race cars like the Aston Martin Racing V8 Vantage GTE I drove in Portugal earlier this year set the driver far back in the chassis, compromising outward visibility.

The NSX GT3’s steering wheel is overwhelming upon first glance but Eversley calmly briefs me on what I need to know and, more importantly, what I can ignore. The biggest change from other GT race cars I’ve driven is the hand clutch, as the dual-clutch NSX road car wasn’t designed to accommodate a wider, clutch-equipped racing pedal box.

First gear clunks in after I pull the hand clutch with my left pinky finger and then select 1st gear by pulling a shift paddle. Acura set the clutch into auto mode, allowing me to release the hand clutch at a standstill. As I add throttle, the racing clutch begins to automatically engage and the NSX GT3 shakes and bucks off the line. (Acura is still working on the tuning of the auto clutch for use during pit stops in competition.)

Once on the track, that hand clutch isn’t needed and I begin to warm up the tires and brakes, as well as my brain. I know the track well, but not the car. Despite a drop of nearly 1000 pounds compared to the 3,803-pound road version, the NSX GT3 doesn’t feel insanely fast in a straight line, but I quickly gather that the race car has serious pace. Gear ratios are fixed by the FIA, so the power band of the V-6 is very wide to compensate. As such, the powertrain never comes alive, per se, and simply develops plenty of power at all times. The large steel brakes are incredibly strong and confidence inspiring but do take a healthy stab from your left or right foot due to the lack of power assistance.

Acura’s tuning of the Bosch Motorsports ABS braking system is spot-on and I follow an Acura engineer’s advice to use the lock-up limiting feature at will. In other words, push the pedal as hard as I like, any time I like. It’s sound advice that allowed me to push the limits of the NSX GT3 sooner than anticipated. The steering is equally linear and trustworthy, adding to my comfort level. It’s the same electric power steering rack as the road car and Niffenenger told me development took loads of time and effort. It shows.

My second session allowed deeper exploration of the NSX GT3’s dynamics. I was able to tie together some quick laps and play with the handling at a faster pace. Traction out of low-speed corners is magnificent, helped by a well-tuned race-spec traction control system. The mid-engine twitchiness I expected never materialized and I was able to comfortably tighten my line and counter any understeer with a forgiving press of the throttle. The six-speed Xtrac sequential gearbox bangs off shifts like a rifle and any and all inputs from my hands or feet instantly alter the chassis — but not remotely in a nervous way. It’s a very impressive package that’s clearly built by a group of highly skilled racing engineers who understand how to build a top-spec GT car.

Even more remarkable is the fact that Acura developed a GT3 race car that can win races in its first year on the track — not remotely an easy task. The Michael Shank Racing IMSA team had their first visit to the top step of the podium with Acura in Detroit in early June. The NSX GT3 is a race car that allows a pro driver to fully extract the maximum performance potential against the best GT3 cars and drivers but still lets a gentleman racer feel comfortable behind the wheel and turn the lap times needed for a multi-driver endurance series effort to succeed.

For now, the NSX GT3 is a North America-only program. Given the popularity of GT3 racing on a global scale, however, we should see the impressive Acura racer on circuits in more countries in the near future.

 

The post First Laps: Acura NSX GT3 appeared first on Automobile Magazine.



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