Porsche 997 based Ruf RT 12

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Porsche 997 based Ruf RT 12

Excellence, 23 Jan 2006

Porsche 997 Based Ruf RT 12

Porsche 997 Based Ruf RT 12

Porsche Ruf RT 12

Ruf RT 12

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Some will say the Ruf Rt 12 should have been called Ruf CTR3 — it certainly has the visual and performance credentials to justify that hallowed moniker. Instead, Alois Ruf decided

Like all good alchemists, Alois Ruf has perfected the art of accelerating the timescale of his craft. The fantastic Ruf CTR2 emerged fully two years into the life cycle of Porsche's 993, but barely six months passed between the debut of the Porsche 997 Carrera and the first public showing of the Porsche 997 Based Ruf RT 12 at 2004's Essen Motor Show.

Some will say the Porsche 997 Based Ruf RT 12 should have been called Ruf CTR3 — it certainly has the visual and performance credentials to justify that hallowed moniker. Instead, Alois Ruf decided to use the Porsche 997 Based Ruf RT 12 (Ruf Turbo 12) designation to commemorate the fact that this is the 12th turbocharged Ruf model to leave his Pfaffenhausen factory. Latest in a lineage of 200+mph Ruf cars with Group C twin-turbo technology that started with 1988's legendary Ruf CTR “Yellow Bird,” the Ruf RT 12 is also the fastest Ruf car ever.

While the Porsche Based Ruf CTR reached 211.5 mph in 1988 and went on to record 213 mph, the Porsche 997 Based Ruf RT 12 will easily nail 217 mph — with the shorter of its two optional final drives. On the way there, its zero to 62 mph and 99 mph times of 3.3 seconds and 6.6 seconds significantly beat the vintage Ruf CTR's numbers. Even so, at 3.6 and 7.3 seconds, the old hero of the eighties is still spectacularly fast — even by modern standards. Progress, however, dictated the new Porsche 997 Based Ruf RT 12 had to be faster than its spiritual grandfather.

That much seems obvious, but it was not easy to do. In fact, it's taken 650 horses from 3.8 liters to decisively beat 469 bhp from 3.4 liters. It must be noted that all of Ruf's power quotes are on the conservative side — a rare trait in this business. Each 911-based Ruf CTR left the factory with roughly 500 bhp and the top 997-based RT 12s are certainly good for more than their claimed 650 bhp. The reason the old car has remained so hard to beat in outright performance comes down to one thing: curb weight.

Ruf CTR 001 was a stripper that weighed roughly 2,600 pounds — a shocking 800-ish pounds (!) less than the lightest RT 12. But ultimate firepower plus superior traction has finally won out. The old Ruf Yellow Bird — built as a narrow-body car for a high top speed — was forced to do its business on skinny, 255-mm rear tires. So it couldn't deploy all of its power in first and second gears. Obviously, the new Porsche 997 Based Ruf RT 12's 305-mm gumballs go a long way toward fixing that problem.

As impressive as these power and performance numbers may be, the reason Ruf customers keep coming back for more year after year goes far deeper than just a need for speed. The fanatical loyalty of Ruf clientele — we've bumped into some of them several times at both the Pfaffenhausen factory and the company's annual events — extends from the fact that Ruf is seen as a manufacturer rather than a tuner by the Kraftfahrt Bundesamt (German Transport Authority), and can thus build cars from bare shells with its own chassis and engine numbers.

In addition, Alois and Estonia Ruf take the time to get to know each and every customer personally. Buyers are welcome to visit while their “baby” is in its gestation period, so it's little wonder that the cars Ruf delivers literally become like members of an extended family. When you buy a Ruf car, you are also buying into a living legend. The Porsche 997 Based Ruf RT 12 is the latest chapter in this legend and, as far as we are concerned, it's also one of the most purposeful looking cars ever to emerge from the Ruf workshops.

While 1988's Ruf CTR had its own distinct look as a narrow-bodied interpretation of the factory RSR and SC/RS, Ruf went into a conservative period with its Porsche 964 based Ruf BTRs. Within that generation of Ruf, an overwhelming emphasis was placed on the engine, suspension, and wheels before any visual or aerodynamic addenda. Swinging the other way with the Porsche 993 based Ruf CTR2 especially in wide-bodied Sport form Ruf delivered the ultimate shock and awe experience to customers who were used to extreme speed in a plain wrapper.

Since then, Ruf's 996-based cars — such as the GT3-based R-GT and R-GT RS — have been steadily building up to a new aesthetic climax, each one different enough from the one before it to avoid the sort of visual anaesthesia major auto manufacturers practice so well. The R turbo 590 we drove last year was a technical and driving tour de force, but looked a bit tame beside the Porsche 997 Based Ruf RT 12 we've come to drive today. By marrying the next step up the technical ladder from this amazing car — with some of the extrovert visual character of the R-GT RS mixed in — Ruf Automobile has hit the nail on the head with the Porsche 997 Based Ruf RT 12. It's a 911 that is exciting to look at and distinctively Ruf in character while avoiding the controversial cues that defined the mighty Ruf CTR2.

The RT 12's bodywork is distinctive, its new nose different from anything else out there. To our eyes, it strikes the perfect balance between looking purposeful and meeting the intake requirements to feed the bigger radiators and coolers. Form follows function can be a very good thing. The rear wing on this RT 12 is fixed and its rear fenders are an inch wider on each side than the 997 Carrera 4. Those swollen arches are filled out by 19x11-inch alloys shod with 305/25ZR19 Pirelli P Zero Rosso tires. The front wheels are 19x8.5-inchers with 255/35ZR19 rubber. Ruf offers two styles of wheel in these sizes. Both the traditional Ruf five-spoke wheels and the multi-spoked rims with forged centers (as fitted to this car) are made by O.Z. Racing.

As with all Ruf twin-turbo motors, the heart of the flagship RT 12 powerplant is the tried-and-tested block penned by Porsche engine guru Hans Mezger and used in Porsche's 911 GT1, 996 Turbo, 996 GT2, and all 996 GT3s. While the Porsche 997 based Ruf RT 12 options list shows entry-level 530- and 560-bhp motors that achieve their respective power levels without internal engine work, we suspect most customers will sign up for the full-house 650-bhp version. In the absence of a Porsche 997 Turbo to work from — which will likely be based on this redoubtable engine block anyway — Ruf simply continued its development of the mighty R turbo 590 motor. If Porsche does go to a new block with its Porsche 997 Turbo, the Ruf RT 12 may be the last game in town for the original split-case faithful.

In the same practice used for the Porsche based Ruf R turbo 590's motor, donor engines for the 650-bhp package are stripped down to check their overall condition and to perform some internal gas-flow work. This labor-intensive process more than doubles the cost over Ruf's 560-bhp conversion — the highest power level Ruf offers without opening an engine up. The work can only be carried out at Ruf's factory in Germany, so the 650-horse Ruf motor is not a bolt-on conversion that can be shipped abroad in a box.

The major physical difference between the Porsche based R turbo 590 and the top Porsche 997 based Ruf RT 12 is a bump in displacement from 3.6 to 3.8 liters. The other big change is the turbos, which benefit from several revisions. Both engines share a custom cast-aluminum intake manifold and the same enlarged throttle body. The cylinder heads are similar, but the light and strong titanium connecting rods are different because the Porsche 997 based Ruf RT 12's 102-mm Mahle pistons use a different wrist-pin location. The six pistons also move within new cylinder blocks.

The cylinder heads are gas-flowed while revised intake and exhaust cams make full use of the enlarged 3.8-liter displacement. Two special Ruf/KKK turbochargers from the K24 family are set for a maximum boost pressure of 1.1 bar (15.95 psi) via a recalibrated Motronic engine management system. Ruf says each turbocharger family has many possible combinations of impellers and housings and that his optimum combination promotes both good low-speed tractability and top-end power.

“Today's standard Porsche factory motor is really excellent in this respect,” says Alois Ruf. “I judge the quality of an engine not just by how many horsepower it makes at peak, but also that so it does not lose any of the driveability that it comes with in standard form. The 0-60 mph sprint is a test done by all car magazines — and an industry benchmark — but it is unrealistic in everyday driving and also very hard on a car's drivetrain. In the real world, flexibility and overtaking punch are what really matter. So, although our cars are fast against the stopwatch, it is in flexibility and smoothness that we make our real case.”

As with all Porsche 911 based Ruf models, the customer has the choice of rear- or four-wheel-drive. Our bright red test car had the latter and, while some may prefer the simplicity, purity, and excitement of two driven wheels at the rear, there is a good argument for selecting all-wheel-drive: It's an ideal setup for deploying 650+bhp in all road and weather conditions. While rear-engine, rear-driven 911s — with their inherently good traction — have a certain traction advantage over their rivals, the Porsche 911's advantage becomes overwhelming with AWD. It's the reason Porsche AG switched to AWD for its own 911 Turbos starting with 1996's 993 Turbo. And it's never looked back.

But even without AWD, the traction advantage that the rear-engined Porsche 911 has off the line shows up in the numbers the first rear-drive RT 12 put down. That car tipped the scales at 3,373 pounds and clocked a devastating 3.3-second sprint to 62 mph and hit 99 mph in 6.6 seconds. It reached 124 mph — or 200 km/h — in just 9.7 seconds. This final test isn't familiar to Americans, but the Porsche 997 based Ruf RT 12's time here is an important yardstick for Alois Ruf.

“This is the first car we have ever built that can crack 10 seconds to 200 km/h,” beams Ruf. At the other end of the scale, top speed is 349.7 km/h — or 217.3 mph — with the shorter of two available final-drive ratios. Ruf says the taller ratio will push the Porsche 997 based Ruf RT 12 to 360 km/h, which translates to nearly 225 mph!

If you are a power and torque junkie, the top Porsche 997 based Ruf RT 12 will be most gratifying. Where the R turbo 590 delivers 590 bhp with 612 lb-ft of torque, the RT 12 punches out 650 bhp and a fantastic 641 lb-ft of twist. Says Ruf: “The 590 was an interim step in our development program. The Porsche 997 based Ruf RT 12 motor is the real thing!” When Excellence drove the R turbo 590, we were astonished and enthused more than anything by the character of the engine, which was changed significantly by its lightweight internals. Never before had we encountered a 3.6-liter flat six that spun like a 1.6-liter inline four.

With its larger 102-mm pistons, the Porsche 997 based Ruf RT 12's 3.8-liter engine has a different character again. It is not quite as free-revving. But while the R turbo 590 has a very linear pull all the way from idle to its fuel cut-off, the more powerful Porsche 997 based Ruf RT 12 has a pronounced power step around 4000 rpm. As the needle sweeps past 4, the 3.8 seems to get a second wind and pushes even harder. It's a characteristic of the bigger turbochargers and makes the car feel more like a civilized and very strong version of a traditional turbo motor — rather than the 7.0-liter, normally-aspirated engine we felt the 590 more closely approximated.

That said, the Porsche 997 based Ruf RT 12 engine also pulls smoothly, with progressive throttle input. When we did our usual party trick of dropping the car into sixth gear and letting the revs fall to 1000 rpm at 30 mph, it pulled cleanly all the way up. With torque as its strongest suit — with nearly 50 percent more than a Porsche Carrera GT — the Porsche 997 based Ruf RT 12 takes off from 2000 rpm like a rocket. Making a turbocharged engine that pulls smoothly from 30 mph to well over 200 mph in one gear is quite an achievement — but that's what years of twin-turbo tinkering gets you.

The extra pace of the Porsche 997 based Ruf RT 12 necessitates even larger brakes. Where the R turbo 590 used 330-mm discs all around with six-piston calipers in front and four-pistons in each rear, the Porsche 997 based Ruf RT 12 has 380-mm front discs with eight-piston calipers. The rear brakes are the same as the 590's. These provide staggering retardation from the heady speeds this car so easily reaches. At the same time, pedal feel is progressive and the exact input force required is easy to judge.

Deploying that power with perfect control is down to the Ruf suspension kit and upgraded bushings. There are two basic suspension systems offered — a conventional setup or a hydraulic-lift system for customers who live in places where parking-lot entrances, steep driveways, and other obstacles are an issue. The standard Porsche 997 based Ruf Ruf RT 12 suspension kit is made by Bilstein, while Φhlins manufactures the hydraulic system, which can increase the ride height by two inches at the touch of a button.

One thing is clear, though: There is no lateral slack in this Porsche 997's rear suspension bushings, under power or otherwise. Now highly sensitized to this after our experience in the early factory 997s equipped with PASM suspension, we instinctively look for it on any 997, factory or tuned, that we drive. In fact, the Porsche 997 based Ruf RT 12 feels solidly bolted down no matter what the road surface and no matter how hard you apply power coming out of a bend.

Part of this handling precision is a by-product of the also-optional Ruf integrated roll cage, installed while the car is still a bare shell. According to Ruf, its IRC adds at least 25 percent to the bodyshell's torsional stiffness, making it a highly stable platform for upgraded suspension. The result? The Porsche 997 based Ruf RT 12 delivers a huge amount of driver confidence and shows just how vital all-wheel-drive, a stiff structure, and a well-sorted suspension system can be in rounding out the performance envelope of a 600+bhp supercar.

We don't doubt that the rear-wheel-drive Porsche 997 based Ruf RT 12 is the more exciting — and more challenging — choice. But for more people more of the time, the all-wheel-drive Porsche 997 based Ruf RT 12 will be deploying more of its power more of the time. Couple this to the supreme tractability of this motor as well as its bombastic thrust on full throttle and you have a perfect recipe for the ultimate late-model Porsche 911. The only question — as always — is where do we go from here?

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