Now that Steve Millen and his Stillen crew have completed the tear-down and build-up of his Nissan GT-R for the Targa Newfoundland, we thought what better way to gauge the progress they've made than by pitting it against the 2010 Nissan GT-R.
First, a quick refresher on what Stillen has done with its GT-R: In the interest of reducing the GT-R's hefty, near-4000-lb. curb weight, Stillen put the car on a serious diet. The interior was gutted, lightweight race seats fitted, carbon-fiber body panels attached (hood, trunk, rear wing and side mirrors), along with a new front urethane spoiler and side skirts designed and built in-house at Stillen. The first-ever fitment of AP Racing's carbon-ceramic rotors to a GT-R not only shaved pounds (10.9 lb. per corner!), but the system is immune to fade — and will theoretically last forever. A full rollcage, necessary for safety, unfortunately added back in over 100 lb.
A reflashed ECU, 15 psi of boost and a free-flowing central-outlet Stillen exhaust (from the turbos back) add up to about 620 bhp on 91-octane fuel, versus 485 bhp for the stock 2010 GT-R. Millen says he retained the stock turbos "because I wanted really good throttle response — a lot of the steering of the car is through the throttle, and I don't want to wait for the power to come on."
Stillen also added a Stillen/Eibach suspension system, consisting of mega-adjustable shocks with 10-percent stiffer Eibach springs along with 3-way adjustable Stillen anti-roll bars. Stillen easily could have built the world's meanest GT-R track car, with a super-stiff suspension and front-airdam-scraping ride height. But that wasn't the goal here: "We have a lot of adjustability in the car," Millen said. "We can change the ride height, the rebound and so on. But we're really trying to keep the tires on the ground — that's the key. And we'll adjust the car to make that happen."
Acceleration
The Stillen GT-R's power advantage was obvious from the first drag launch. Even forgoing the car's launch-control system (at Millen's request) — building revs to only 2000 rpm — resulted in 0-60 mph runs about the same as those of the stock car, which ran 3.5 seconds. When we increased revs to about 3500 rpm (still not invoking launch control), Stillen's GT-R leapt out of the box spinning all four tires for a run to 60 mph in an astonishing 2.9 sec. The experience in the stock version, whose launch control rpm has been lowered to 3000 rpm for 2010, was far more mundane, although 3.5 sec. is still impressively quick.
The sheer power of the Stillen was further proven by its 11.0-sec. quarter mile run at 127.9 mph, vs. the stock GT-R's 11.7 at 120.4. Even more telling was the run to 130 mph: Stillen in 11.4 sec., stock in 14.0 — that's some power! What's more, Millen says he could have easily bumped the boost to 17 psi (good for another 60 bhp or so, and no doubt a quarter-mile run well into the 10s), but he wanted us to test the car in the same power configuration in which he will run the Targa.
Pound for Pound
Interestingly, despite the weight savings Stillen achieved with its GT-R, the Targa car wasn't quite as light compared to the production car as we thought it would be. Millen figures nearly 400 lb. was taken out of his car (he weighed most of the parts himself), but our scales registered only a 172-lb. advantage for the Stillen. What gives? For one thing, Millen's car was a pre-production 2009 model (one of the very first cars brought into the U.S.), and although we never got a chance to throw it on our scales before the Targa build process, Millen did. He has a certificate registering 3900 lb., which means his car started out quite a bit heavier than the 3792-lb. 2010 test car. That extra 100 lb. or so, along with the addition of a rollcage that easily weighs over 100 lb., means Millen's near-400-lb. weight-loss figure computes.
Braking
With the installation of 15.7-in. AP Racing carbon-ceramic brake rotors, it's natural to expect this system would whoa the GT-R down to a halt much better than the slightly smaller stock steel brakes. But as we found when we tested a Nissan GT-R SpecV with carbon-ceramic rotors, quite often panic stop lengths end up just slightly longer. That's what happened here, with the production GT-R halting from 60 mph in 114 ft. versus the Stillen's 117; from 120 mph, the stock car needed 443 ft. while the Stillen required 457. Although Millen was hoping for better numbers, where the carbon-ceramics will really shine is repeated hard use without any sign of fade — just the kind of duty required in the Targa Newfoundland.
Skidpad
Since both GT-Rs were fitted with identical Bridgestone Potenza RE070Rs, we expected a close fight around the skidpad, and we got it. Both showed similar slight understeer, but in the end the Stillen gripped just slightly better (0.98g Stillen vs. 0.96g stock). We feel this is due to the Stillen's 172-lb. weight advantage, as well as its different suspension tuning.
Slalom
Our first few runs through the slalom netted near-equal times for both GT-Rs. The stock car exhibited slightly crisper turn-in, which caused the Stillen boys to fiddle with their suspension, in an effort to alleviate the initial turn-in understeer we were experiencing. Through a combination of stiffening the Stillen's rear anti-roll bar, adding more compression damping to the front shocks and less rebound in back, we eventually snaked around the cones quicker in the Stillen: 73.8 mph vs. 73.1 mph stock.
Sound check
If the Stillen GT-R's custom bright orange paint job doesn't attract attention in Newfoundland, its piercing exhaust note surely will. How much louder is it than stock? For fun, we took some measurements: At idle, the Stillen registers 68 dBA, compared to the production car's 56. But it's at high revs that the Targa GT-R releases its full fury, to the tune of 101 dBA (at max revs in 1st gear) versus 81 dBA stock. Newfoundlanders are going to love the Stillen's race-car-like snarl; that is, if they're not too busy running for cover.
Driving: Stock vs. Stillen
Obviously, Stillen's GT-R is immensely louder (it sounds terrific, but it does rattle your brain a bit) than the production car. Beyond that, the Stillen car is livelier in the way it drives and handles. Plus, the increased power and near-instantaneous boost make the Stillen GT-R easier to slide around for grins. The ride quality is hardly harsher than stock, while the ride height is only about a half inch lower — because Millen is bound to catch some air over crests in Newfoundland, it's important the car doesn't bottom easily.
But the biggest difference between the Stillen GT-R and the stock GT-R is sheer power: Bury the throttle in a side-by-side drag race — no launch control, no power-braking, just get on it and go — and the Stillen GT-R makes like Usain Bolt, easily outdistancing the production car. Just as with Bolt, it's not even close.
Shut up and race
So the numbers are in, and Stillen has clearly done a great job making the GT-R into a faster and better handling sports car. But running numbers at our smooth El Toro test location is one thing; managing the notoriously rough roads of Newfoundland quite another. How will the new suspension soak up the bumps? Will the car's extra power affect reliability? And how will the Stillen GT-R stack up against the competition? We look forward to answering all these questions, starting on September 14th.
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