Serious Business: McLaren 600LT vs. Porsche 911 GT3 RS

In the same way that water is wet, the Porsche 911 Carrera is a performance car. Opt for the S version, and things get even quicker and sportier. Go for the GTS, and the car becomes spicier. Enter the GT3. Built by Porsche Motorsports, the same folks who develop and construct the race cars, the GT3 is truly a next-level performer. Hate the 3.0-liter turbocharged flat-six and bunched-up seven-speed manual on the “regular” 911? So, too, does Andy Preuninger and the rest of his Flacht-based crew. That’s why the GT3 has a screaming mimi of a 9,000-rpm 4.0-liter naturally aspirated boxer-six that makes more than 500 horsepower and a race-derived, brass-bushing six-speed manual. Andy and his team feel the GT3 can barely cross the street by itself, so they built the GT3 RS.

Lighter, with 20 more horsepower, a PDK (seven-speed dual-clutch) only, more grip, more downforce, more noise—and, just generally speaking, more—the RS version has but one mission: to make whoever’s driving it go quicker around a track. At Road Atlanta, our pro driver Randy Pobst ran the track in the GT3 RS in 1:26.24, beating the 755-hp Corvette ZR1’s time (1:26.45) before besting himself in a 691-hp GT2 RS (1:24.88)—meaning that the GT2’s extra 177 ponies netted only 1.36 seconds.

McLaren doesn’t care. It showed up to our party packing its latest and greatest, the 600LT, the hopped-up, raced-out version of the 570S, a former MotorTrend Best Driver’s Car winner. Nearly a quarter of the 600LT’s parts are new, power is up from 562 to 592 hp, weight is down, and yes, the thing literally spits flames from its top-mounted exhaust tips. Both track-day missiles are performance variants of performance variants. They may not be the fanciest, most expensive cars either manufacturer sells, but in more ways than one, they are the purest. The Porsche doesn’t use the crutch of turbos or electric motors to go quick. Rather, the engineers pulled out every stop they knew. And although all McLarens are turbocharged (and will all soon be electrified), the latest Longtail car forgoes the complex and heavy hydraulic suspension found on big brother 720S in favor of simple, effective springs and dampers. Which car is the better ultra-high-performance track weapon? Keep reading!

Want to see the full episode? Sign up for the MotorTrend App HERE, and check out more Head 2 Head episodes HERE.

At the Test Track

Yeah, these cars rip! In terms of acceleration, it should come as no surprise that the 3,101-pound 600LT beats the 3,245-pound GT3 RS off the line. What is surprising is by how much. The McLaren hits 60 mph in a ridiculously quick 2.9 seconds. The Porsche? Three seconds flat! After all these years, some people still talk smack about 911s, saying silly things like, “The engine’s in the wrong place.” I always counter by pointing out that little is better for acceleration than having all the weight over the driven wheels. By the end of the quarter mile, the McLaren’s horsepower advantage is fully apparent, with the Brit needing only 10.5 seconds (the same as both a Porsche 911 Turbo S and a Tesla Model S P100D Ludicrous+) at 137.3 mph to the Porsche’s 11.0-second run at 127.6 mph. The quickest Nissan GT-R we’ve ever tested ran an 11.0-second quarter mile.

In terms of braking, the Porsche out-stops the McLaren by 6 feet. Now, both cars stop from 60 mph in less than 100 feet, and anything under 100 feet is world class. But 98 feet for the 600LT is nowhere near as good as the GT3 RS’ 92 feet, one of the shortest stopping distances we’ve ever recorded. I suppose I should get this out of the way: The Michelin Pilot Sport Cup 2 R N0 tires are really, really, really good. That’s three reallys. This triple-really goodness shows up in our figure-eight test, too. The quickest figure-eight time for a production car we’ve ever recorded is 21.9 seconds by the Porsche GT2 RS—on the same tires. The GT3 RS comes in second, at 22 seconds flat. What about the McLaren 600LT? It made 22.2 seconds, putting it in a three-way tie for third place with the Lamborghini Huracán Performante and the Porsche 918 Spyder. Gulp. Two solid performers, no?

	2019 McLaren 600LT Coupe	2019 Porsche 911 GT3 RS
POWERTRAIN/CHASSIS
DRIVETRAIN LAYOUT	Mid-engine, RWD	Rear-engine, RWD
ENGINE TYPE	Twin-turbo 90-deg V-8, alum block/heads	Flat-6, alum block/heads
VALVETRAIN	DOHC, 4 valves/cyl	DOHC, 4 valves/cyl
DISPLACEMENT	231.8 cu in/3,799cc	243.9 cu in/3,996cc
COMPRESSION RATIO	8.7:1	13.3:1
POWER (SAE NET)	592 hp @ 7,500 rpm	520 hp @ 8,250 rpm
TORQUE (SAE NET)	457 lb-ft @ 5,500 rpm	346 lb-ft @ 6,000 rpm
REDLINE	8,700 rpm	9,000 rpm
WEIGHT TO POWER	5.2 lb/hp	6.2 lb/hp
TRANSMISSION	7-speed twin-clutch auto	7-speed twin-clutch auto
AXLE/FINAL-DRIVE RATIO	3.31:1/2.27:1	4.19/3.53:1
SUSPENSION, FRONT; REAR	Control arms, coil springs, adj shocks, anti-roll bar; control arms, coil springs, adj shocks, anti-roll bar	Struts, coil springs, adj shocks, anti-roll bar; multilink, coil springs, adj shocks, anti-roll bar
STEERING RATIO	14.7:1	13.1-17.2:1
TURNS LOCK TO LOCK	2.3	2.5
BRAKES, F; R	15.4-in vented, drilled carbon-ceramic disc; 15.0-in vented, drilled carbon-ceramic disc, ABS	16.1-in vented, drilled carbon-ceramic disc; 15.4-in vented, drilled carbon-ceramic disc, ABS
WHEELS, F; R	8.0 x 19-in; 11.0 x 20-in forged aluminum	9.5 x 20-in; 12.5 x 21-in forged aluminum, central locking
TIRES, F; R	225/35R19 88Y; 285/35R20 104Y Pirelli P Zero Trofeo R MC	265/35R20 99Y; 325/30R21 108Y Michelin Pilot Sport Cup 2R N0
DIMENSIONS
WHEELBASE	105.1 in	96.6 in
TRACK, F/R	66.1/62.6 in	62.5/61.3 in
LENGTH x WIDTH x HEIGHT	181.3 x 76.0 x 47.0 in	179.4 x 74.0 x 51.1 in
TURNING CIRCLE	39.7 ft	36.4 ft
CURB WEIGHT	3,101 lb	3,245 lb
WEIGHT DIST, F/R	42/58%	39/61%
SEATING CAPACITY	2	2
HEADROOM	37.6 in	37.7 in
LEGROOM	42.4 in	42.2 in
SHOULDER ROOM	51.9 in	51.3 in
CARGO VOLUME	5.3 cu ft	4.4 cu ft (9.2 cu ft behind seats)
TEST DATA
ACCELERATION TO MPH
0-30	1.4 sec	1.3 sec
0-40	1.9	1.7
0-50	2.4	2.3
0-60	2.9	3.0
0-70	3.4	3.7
0-80	4.2	4.6
0-90	4.9	5.6
0-100	5.8	6.8
0-100-0	9.7	10.4
PASSING, 45-65 MPH	1.0	1.3
QUARTER MILE	10.5 sec @ 137.3 mph	11.0 sec @ 127.6 mph
BRAKING, 60-0 MPH	98 ft	92 ft
LATERAL ACCELERATION	1.09 g (avg)	1.19 g (avg)
MT FIGURE EIGHT	22.2 sec @ 0.97 g (avg)	22.0 sec @ 0.98 g (avg)
2.4-MI ROAD COURSE LAP (WET)	84.71 sec (92.18 sec)	83.67 sec (95.08 sec)
TOP-GEAR REVS @ 60 MPH	1,750 rpm	2,600 rpm
CONSUMER INFO
BASE PRICE	$242,500	$189,850
PRICE AS TESTED	$309,310	$225,940
STABILITY/TRACTION CONTROL	Yes/Yes	Yes/Yes
AIRBAGS	6: Dual front, side/head, knee	8: Dual front, side, curtain, knee
BASIC WARRANTY	3 years/Unlimited miles	4 years/50,000 miles
POWERTRAIN WARRANTY	3 years/Unlimited miles	4 years/50,000 miles
ROADSIDE ASSISTANCE	3 years/Unlimited miles	4 years/50,000 miles
FUEL CAPACITY	19.0 gal	23.8 gal
EPA CITY/HWY/COMB ECON	15/23/18 mpg	15/19/16 mpg
ENERGY CONS, CITY/HWY	225/147 kW-hr/100 miles	225/177 kW-hr/100 miles
CO2 EMISSIONS, COMB	1.09 lb/mile	1.17 lb/mile
RECOMMENDED FUEL	Unleaded premium	Unleaded premium

On the Dyno

We decided to place both cars on the dynamometer to see how much power they actually make. Porsches are known for their—how to put this politely—Germanness. If the factory says the GT3 RS makes 520 hp, it’s a very safe bet that it makes 520 hp. McLaren, on the other hand, is known for … variance. There’s a viral video that shows a stock 720S pumping out an easy 800 crank horsepower.

Oh, yes—wheel versus crank. Dynos measure the power at the wheel. Crank horsepower refers to the power being fed to the crankshaft, which then routes it to the transmission, driveshaft, differential, and halfshafts before it finally spins the wheels. Each one of those components creates a phenomenon called parasitic loss. If it takes 50 horsepower to spin the transmission, all 50 horses don’t make it to the wheels. With complex and relatively heavy dual-clutch transmissions, the rule of thumb is 20 percent parasitic losses.

According to the big machine at K&N Filters, the Porsche produced 430 hp at the rear wheels, which is—surprise—17 percent off 520. On the money. The McLaren’s results were different: 530 horsepower at the wheels means the 600LT either makes 640 hp or sacrifices just 10.5 percent drivetrain loss. Shocked, not shocked.

Hit the Road

On the street—oh, yes—the McLaren does feel like it has a higher gear compared to the Porsche. Or 130 extra ponies, at any rate. The 600LT doesn’t pump terror into the driver’s heart the way the 720S does. But it sure scares the lunch out of the passenger. Sometimes, that’s what you want. The McLaren also feels like a cross between a fighter jet and an X-wing fighter. The seating position, the view out the front canopy, and of course, the billionaire doors—all of it is killer cool. The Porsche, by way of contrast, feels like a Porsche. Alcantara all the things and make the seat tight! To be fair, the thrones in the McLaren are snug, too.

Once I was driving, the Porsche felt … I hate using the word “perfect,” and obviously I’d rather the GT3 RS had the amazing six-speed manual racing gearbox like you can get in the regular-calorie GT3, but friends, Romans, countrymen—the Porsche Motorsports folks are quite skilled at what they do. Remember, this GT3 RS is the 991.2 version, meaning the GT team iterated the 991.1 GT3, then that version of the RS (as well as the 911R), then started again with the 991.2 GT3 (and the GT2 RS, too) before finally getting their hands dirty with this orange beauty. The results are not quite perfect—but not far off, either.

Grip was through the roof. Sure, some of that is down to the tires, but much of it is because of the mechanical tinkering on the part of the GT team. The 991.1 GT3 RS wasn’t nearly as stable—it was built like the Ferrari F12tdf. It’s sketchy at the limit, which pays off if you’re a capable enough driver to anticipate the rear end moving around. Bad news if you’re the normal type (hi, Mom!) who has to react to oversteer. The new RS? Totally planted. To me, the rear end felt identical to the GT2 RS and its magical torque-vectoring rear differential. I had no fear that anything would go wrong, and ultimately, driver confidence is what it’s all about.

This GT3 had the $18,000 Weissach package, as well as the $3,100 lightweight magnesium wheels. So the roof, anti-roll bars, and drop links are all carbon fiber, as are the shift paddles. Half the glass is thin (and noisy) Gorilla Glass, and many of the body panels are made of carbon, too. What amazes me most about Porsche is its ability to slice and reslice the 911 pie. I’ve driven nearly every iteration of the 991, and I’m still shocked at how different each one feels. The GT3 RS isn’t that different on paper than the GT3 (a few bullet points, really), but man, do they feel night and day. Speaking of that exact phenomenon …

All modern McLarens are built around a mid-mounted, twin-turbo V-8, a seven-speed dual-clutch transaxle, and a carbon-fiber tub. Yet it’s hard to believe that the 570S and 720S are from the same manufacturer, let alone the same country. The 600LT might be 77 percent identical to the aforementioned 570S, but it feels like another species. Remember, chimpanzees are 99 percent genetically identical to human beings. Some of us even more so.

McLaren also has an unfortunate habit of taking everything it learned from its last car and applying it to the next one, price be damned. Like the Senna’s brakes? Well, the 600LT is better for it. Sadly, McLaren still hasn’t figured out consistency from vehicle to vehicle. I’d driven a 600LT on the launch at the Hungaroring outside of Budapest, and that car felt more sorted than this white example. My Head 2 Head co-host, Jethro Bovingdon, had previously driven two 600LTs, and he found the same to be true. To be totally fair, McLaren didn’t want to give us this particular car, which lacked the sport seats and some of the other ultra-lightweight bits. McLaren felt a fully MSOed 600LT could have weighed 100 pounds less.

Due to circumstances beyond anyone’s control, this was the only car available. More important, McLaren came through, which meant I didn’t have to fly to Woking to throw eggs at the Technical Center. Unlike the other 600LTs Jethro and I had driven, this car has entry understeer. Whereas the Porsche flirted with being almost too easy to drive, piloting the more hands-on McLaren was much more of a challenge—but also more rewarding. Depends on what you like. On the road, both cars are superstars.

Randy the Rocket in the Rain

Jethro brought miserable British weather with him to the Mojave Desert. Willow Springs, our home track, was drenched. I asked Randy if he was OK driving in the wet. He said he’d be fine, as it rains all the time on his home track, Road Atlanta. Also, he won the 24 Hours of Daytona in the rain. Well, fine then. McLaren’s team of engineers and mechanics brought along some Pirelli street tires, plain old Corsas. Porsche’s people left the GT3 RS on the fancy-pants Michelins. Still, the Brit was nearly 7 seconds per lap quicker than the German on comparable surface wetness. Embarrassing. The McLaren was putting down wet laps similar to a Cadillac CTS-V in the dry, whereas the poor Porsche was just ahead of a Range Rover Sport SVR. Then … well, you can probably guess what happened next.

Porsche Finds a Way

The rain stopped, the sun peeked out, and most important for Team Germany, the notorious winds of Willow Springs blew the track dry. The tables turned, and suddenly the Porsche started flying. So did the McLaren: Randy put down a 1:24.71, the 12th quickest lap we’ve ever recorded. The McLaren 675LT—a car rated 72 horses more powerful, weighing 100 pounds less, and costing much, much more—did a 1:24.29 in the totally dry. I’d bet that if the track conditions had been better, the 600LT would have beaten the 675LT. But it wouldn’t have beaten the Porsche.

The Flacht-built GT3 RS ran a 1:23.67 in the not-quite-dry, the fifth quickest lap we’ve ever seen on Big Willow, a razor-thin 0.13 second behind a 918 Spyder. That’s ridiculous. And if the conditions had been better, the Porsche would’ve gone even quicker. How close could Randy have come to the three cars in front of the 918 Spyder? I’d bet the Lamborghini Huracán Performante’s time of 1:22.53 would be in danger, especially if you figure damp conditions add about half a second per lap and Big Willow is 2.43 miles long. Remember, Randy was just 1.36 seconds quicker in the GT2 RS than in the GT3 RS at Road Atlanta. I imagine we’d see a similar gap here. I’d love to try again. However, the McLaren 720S’ 1:21.75 and GT3 RS’ 1:21.08 remain safe—for now.

So yes, I’d like a rematch. The McLaren 600LT wasn’t the proper version, and I’d love to see what the GT3 RS is ultimately capable of. If it were up to me, every single week of work would be nothing but testing cars like these two. That’s why it’s not up to me. On Instagram (@jonnylieberman) someone asked me if dry and sunny conditions would have helped the McLaren out. Yes, obviously, but remember it would be dry and sunny for the Porsche, too. Still, I’d love to do this one again with a better-sorted 600LT.

All that said, the winner of this comparison test is the Porsche GT3 RS. What a fantastic beast. The part that kills me is that the 992 Porsche 911 just made its debut, and somewhere in southeastern Germany there’s already a GT3 version of it, waiting to be revealed. And you can set your watch to the fact that the men and women behind that upcoming track weapon are already thinking about the RS version. It never ends.

Don’t miss the full episode right here!

The post Serious Business: McLaren 600LT vs. Porsche 911 GT3 RS appeared first on Motortrend.

from Motortrend http://bit.ly/2UJxfIs