Despite the extensive mods, Porsche’s Altitude 911 still drives like a 911.
Porsche put more effort into its heritage than any other manufacturer. You’ll find no shortage of its past highlighted at the events it holds, the museums it curates, and the cars it produces. But Porsche doesn’t just look back at its past accomplishments. It strives to create new milestones too.
The company’s most recent world record is proof. Back in December, the highly modified 911 Carrera 4S you see here was sitting on the peak of the west ridge of Ojos del Salado, the world’s highest volcano, located in the mountains of northern Chile. With three-time Le Mans winner Romain Dumas behind the wheel, it was able to climb to an incredible 22,093 feet — a new altitude record for vehicles.
The idea for this record-setting 911 was born in 2019 in a conversation between then Porsche North America president Klaus Zellmer and Frank Walliser, a vice president on the vehicle dynamics side and lead project manager for the 918 Spyder. They figured such a record would be the perfect way to celebrate the 30th anniversary of the 964 Carrera 4, the first all-wheel drive 911.
| Quick Specs | Porsche 911 “Rock Crawler” |
| Engine | Twin-Turbo 3.0-Liter Flat-Six |
| Output | 443 Horsepower / 390 Pound-Feet |
| Top Speed | ~60 Miles Per Hour |
| Transmission | 7-Speed Manual |
| Ground Clearance | 13.7 Inches |
Engineers built two of these rock-crawling 911s. The first car, affectionately nicknamed Doris, served as more of a proof of concept. The second car, nicknamed Edith, is the car that set the record. Both use a patented suspension system originally destined for the 919 Hybrid Le Mans racer, while only Edith got Porsche’s first steer-by-wire system. There’s also a serious amount of weight-saving material present on Edith that isn’t on Doris.
Porsche wanted to keep the drivetrain as factory-fresh as possible, meaning both use the Carrera 4S’s twin-turbo 3.0-liter flat-six making the same 443 horsepower and 390 pound-feet of torque as they do in the standard car. Both cars use the 4S’s optional seven-speed manual transmission, also unmodified. The only real changes come at the power transfer level, after the transmission. Instead of working automatically, power distribution between the front and wheels is controlled manually through switches on the dash, with the driver being able to choose between rear-wheel drive or all-wheel drive. The locking rear differential is one you’d normally find in a PDK-equipped Carrera 4S, while the front locking diff is bespoke.
The gigantic 34-inch mud-terrain tires dominate the aesthetics of both cars. They sit on 16-inch wheels and help to raise ground clearance to 13.7 inches — more than a Ford F-150 Raptor or Ram 1500 TRX. Also helping with the height are a set of portal axles built into each hub. The gearing, supplied by German off-roading firm Tibus, uses a 1:3.6 ratio, effectively turning first and second gears into crawler gears. Porsche says top speed in 7th is about 60 mph. So you could say this is the slowest factory-built Porsche 911 ever made.
Speed isn’t the point, obviously. This 911 was designed with a singular purpose in mind: To scale the side of a rock-covered mountain while fighting against thin high-altitude air. While a short 15-minute jaunt around a medium-difficulty off-road course in Malibu wasn’t exactly representative of Ojos del Salado’s west ridge, it was enough to show off how a factory-designed rock crawler designed by Porsche could perform far outside the 911’s usual comfort zone.
Aside from the abnormally high position relative to the ground, the Altitude 911 cabins are a familiar place. The seating position is perfect, with the steering wheel, pedals and shifter all in places you’d expect them to be. Doris, the prototype car, still has most of its dashboard, including the central touchscreen. There’s even a working radio with at least one working speaker in the cabin. Edith is a bit more purpose-built, with motorsport-style switches in place of the screen, a real racing bucket, and radiators located right behind your head, complete with electric fans blaring a high-pitch whine directly into your ears.
This 911 was designed with a singular purpose in mind: To scale the side of a rock-covered mountain while fighting against thin high-altitude air.
Setting off in either of these cars is easy thanks to the portal axle ratios. You can creep in first gear at what feels like 2 mph, while redline comes at about 10 mph. That jumps to 20 mph in second gear. It’s only when you get to third and fourth gear do you start to feel like you’re driving a normal car. It’s a jarring sensation, especially if you’ve never driven a car with ratios like this before.
Even more jarring is the suspension. It’s an extreme departure from the standard 911’s setup, and required extensive modification to the unibody to make it fit. Called the Warp Connector, it eschews the idea of independent suspension for a fully interconnected setup. There are two main springs and dampers, one set per axle, that live inboard and connect the wheels left to right. Then there’s a longitudinally mounted bar — the “connector” in Warp Connector — that allows the front and rear to enact force on each other.
This system was supposed to make its debut in 2014 inside the 919 Le Mans racer, but it was shelved. Adapted specifically for crawling over large rocks on a loose surface, it does a fantastic job of making the 911 feel more like a true rock crawler than a sports car. It reacts quickly to imperfections with quick motions, and manages to keep the body stable, even over jagged or severely uneven surfaces. But it also feels nothing like a road car, with lots of micro reactions and a serious sense of urgency at any speed.
That’s not to say these Porsches don’t feel like 911s. Doris, especially, has some stark reminders you’re still behind the wheel of a 992. The steering rack in that car is completely unmodified from stock, and while over a foot of wheel and tire between you and the ground certainly dampen feedback, the bones of what makes modern Porsche steering so great are still there. It’s the same sensation, muted and subtle.
The record-breaking car and its steer-by-wire system, on the other hand, is totally alien in nature. Not because it feels different, but because it feels like nothing at all. There’s less feel here than in some sim racing setups I’ve used. But in this case, that’s not a detraction. Engineers purposefully wanted to dial feel away from the steering wheel for Dumas so he could keep the car pointed straight while the wheels bashed against rocks of different sizes. Specifically, they wanted to eliminate as much of the “kickback” that occurs when you slam into a rock with either of your front wheels. The last thing you want to happen is the steering wheel jolting away from your hands while you’re trying to climb up a mountain hundreds of miles away from the nearest hospital.
The system, called SpaceDrive, works well to point the wheels where you want the car to go, but don’t expect anything when it comes to feedback. It performed exactly as advertised in some of the tougher sections, staying steady inside the cabin without needing many corrective inputs. Engineers told us the feedback could be adjusted as needed, though they didn’t give us a chance to try the different levels.
More than the steering, the car’s rear-engine layout will always remind you that yes, this is still very much a 911. It proved exceedingly difficult to break traction anywhere on the course unless you really went out of your way to do it, thanks to all of that weight on the rear end. The entire course could be done in rear-wheel drive because of the car’s weight distribution. Not once did it feel like this Porsche didn’t belong, a testament to the 911’s sheer versatility.
Weight between the two cars is something you notice more and more as your angle of approach and descent increases. Doris, the prototype car, has a curb weight of 4,651 pounds — 1,249 pounds more than a standard 4S. In addition to the widebody panels, meaty tires, and portal axles, things like a full roll cage and steel underbody protection are big contributors to the extra heft.
The car went on a massive diet for the record attempt. Edith got carbon fiber widebody panels, carbon doors lifted from the 911 GT3 R race car, a plexiglass windshield, perspex side windows, a lighter roll cage, a carbon hood, a carbon dashboard, and Kevlar underbody protection, totaling 793 pounds of weight savings. It’s the biggest and most obvious difference between the two cars, and felt most apparent on the steep downhill portions where you have to rely on the ultra-low first gear to keep you from tumbling down the mountain.
Not once did it feel like this Porsche didn’t belong, a testament to the 911’s sheer versatility.
In Doris, you have to use the brakes a bit to maintain a slow crawl down. But in Edith, engine braking is enough. It’s the same story climbing upwards. In both cars you lean on the rear-engine architecture to keep the rear wheels from spinning, but in Edith, everything is lighter and easier. Both cars had no trouble through this test course, but when you’re more than 22,000 feet above sea level, this engine is only making between 100-200 hp, so every pound saved counts tremendously.
As you read this, both Doris and Edith are in transit back to Porsche’s headquarters to claim their well-earned places at the company’s museum, where they’ll likely sit for decades to come. Still covered in the Chilean dirt they picked up from their ventures into the sky, the cars will tell the story of how even in the year 2023, carmakers and the people behind them can create new legacies we can look back on fondly.
Porsche 911 “Rock Crawler”
Engine Twin-Turbocharged 3.0-Liter Boxer Six
Output 443 Horsepower / 390 Pound-Feet
Transmission 7-Speed Manual
Drive Type Rear-Wheel Drive Or All-Wheel Drive
Maximum speed ~60 Miles Per Hour
Ground clearance 13.7 Inches
Weight 4,651 Pounds (Doris), 3,858 Pounds (Edith)
Seating Capacity 1
