. Cobra Ranch Historical Automotive Blog: Featuring Wally Wyss

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Wednesday, April 6, 2011

The Cobra GR-1 Concept

What is it? The Cobra GR-1 concept
by Wallace Wyss
    Just as the Ford GT was rolling down the assembly line (actually being hand-pushed on dollies at the Saleen plant in Allen Park) Ford took the breath away from Shelby fans by unveiling a sort of modern Daytona coupe interpretation. The Ford Shelby GR-1 was a 2.2 million dollar prototype first seen at the 2005 North American International Auto Show.

     Much of the GR-1 chassis and running gear was based on the previous roadster Shelby Cobra Concept, which had made its debut one year earlier at the 2004 North American International Auto Show. Just as with the Ford Shelby Cobra Concept the GR-1 project was created by Manfred Rumpel and developed by Ford's Advanced Product Creation group.The engine was a 6.4 liter all-aluminum V10 engine using some components from the Ford GT.. The GR-1 was rated up to 605 hp (451 kW) and up to 501 lb·ft (679 N·m) of torque. It uses a 6-speed manual transmission.

----  Specifications  ----



6.4 liter DOHC V10
3900 lbs
501 lb-ft @ 5550 rpm
605 hp @ 6750 rpm
6.4 lbs per hp
94.5 hp per liter
1/4 mile
0-60 mph 
under 4 seconds
Top Speed 
200 mph +

The body at some shows was a new polished-aluminum body, re-creating a link to Cobra history as Shelby polished out CSX2000, the first Cobra in 1962 to show off that it was aluminum.
  But in one shot shown here the body was painted, a result of them denting the aluminum body as they rolled it ou of the trailer for the Pebble Beach Concours (you can bet someone got fired over that). The painted car had a very “busy” grille cavity with lots of separate ducting which was dropped from the polished alloy version

Ford bragged that the car was not just your average pushmobile made for the stage only but  a fully engineered, production-feasible roadgoing, drivable project vehicle.

They even bragged that it was a car that in the words of one executive “might appeal to someone considering a Ferrari 575M Maranello." (ironically at the same time Ford owned Aston Martin which was supposed to be pitching cars against Ferrari…)

Ford said that the chassis started with a modified version of the aluminum chassis from the mid-engine Ford GT. “The bulk of the rear structure is made from slightly modified Ford GT components, including the massive trellis-like, cast-aluminum suspension nodes, the rear rails and bumper beam, a major cross-member and the brackets used to mount the transmission.”

The center portion of the spaceframe also borrowed liberally from the Ford GT as major aluminum extrusions are based heavily on existing pieces. At the front of the coupe, the team incorporated extruded main rails, a steering rack cross-member, crash-management sections and the bumper beam from the Ford GT.

The car was less wasteful in terms of its length compared to the Ford GT, being more than two feet shorter than the Ford GT, with a wheelbase nearly seven inches shorter. The track width was reduced by more than an inch..

The most Daytona like features were the grille cavity shape and in the rear, a distinctive chopped off Kamm tail featuring integrated transmission cooler outlets and a ground-effects venturi.  The Shelby GR-1 concept sat on 19-inch, 12-spoke milled aluminum wheels and featured Goodyear 275/40R-19 tires in the front and 345/35R-19 tires in the rear, mated with the unique Tire IQ™ system, which allows the driver to monitor precise tire performance.

   The doors were what is called “butterfly doors” which had distinctive teardrop-shaped side-glass graphics that created an elongated appearance, blending seamlessly into integrated door-release handles.

The seats were carbon shells and fixed backs. The carbon shells are connected directly to the sill and tunnel via lightweight aluminum spaceframe attachments and can be adjusted fore and aft by way of an accessible pull ring on the seat cushions' leading edge. The seats incorporate removable Alcantara comfort inserts that are individually tailored to the occupants' body type.

The interior door panels feature air-vent apertures and integrated "door close" pockets. The door release employs a pull-ring themed design with quick-release slide action and an illuminated door lock/unlock indicator. The exposed rear bulkhead cross-car structure braces to the roll hoop and features a snorkel air-register outlet that controls the ambient cabin climate.

“Interior cabin technology focuses on driver comfort, enjoyment and entertainment. The instrument panel sports a full complement of analog gauges, including a combination analog tachometer with floating watch-like elements and digital speedometer. The tachometer housing has integrated air registers and an additional Noise Reduction Technology (NRT) output speaker,”said Ford.

Ford went on about the interior “The center console had integrated toggles that control the fuel pump, ignition, windows, hood and rear-glass release. The race-inspired push-button starter and "baseball grip" gear knob are situated ahead of the parking brake, which has been incorporated into the tunnel armrest. The quick-release steering wheel has integrated headlamp, wiper and direction indicator controls.”
Special attention has been paid to noise reduction on the interior. The rear hatch stowage compartment features a removable MP3/Amp and NRT console, while audio input, output and recording speakers are integrated into the headrest protection wings on each seat. The speakers can provide a combination of the following:
·         Noise-reducing sound waves (NRT) for improved highway cruising noise levels
·         Play or record (for playback) pace notes
·         MP3 Audio
·         The MP3/AMP/NRT functions can be interfaced through the Tire IQ™ display through a joystick controller.
Throughout the interior, the leather trim is in slate gray, with color-matched perforated Alcantara leather featured on touch zones such as the gear knob, parking brake, steering wheel, door inserts, and instrument/Tire IQ™ binnacles. Functional zones such as dials, door release and center console switchgear have been finished in a combination of anodized gunmetal finishes.

Ambient cabin lighting is neatly packaged behind the central headlining panel; an indirect blue glow appears around the periphery offset of the panel. The headliner and upper doorframes are trimmed with a woven aluminum-metalized fabric that lightens the interior ambiance and heightens the slate grey tones of the leather and Alcantara trim. The dark gunmetal-gray flooring also is trimmed in the hard-wearing metalized fabric."

Ford engineers built a case for the car having proven components, as if to say: "There is nothigng experimental about this--it is ready to go."
But they did say it was a car with "a more 'mature' feel biased a little more toward driver comfort than the Ford GT – widely noted for its balance of dynamics and road manners – and last year's Ford Shelby Cobra concept.

"They started by attaching massive 19-inch wheels and tires using the Ford GT suspension system with a few modifications to accommodate the increased weight of a front-engine setup. The new Ford GT earns praise for its combination of agility, grip and easy-to-drive character, a reflection of its sophisticated suspension design and the expertise of its chassis engineers. The Ford Shelby GR-1 concept applies the best of the GT suspension to a supercar with different performance intentions."

"The biggest difference between the GR-1 concept and our past efforts is the emphasis on overall driver comfort," said Manfred Rumpel, manager, Ford Advanced Product Creation. "That extends all the way to the compliant yet high-performing capability we built into the suspension."

The suspension was a double-wishbone suspension design with unequal-length aluminum control arms, coil-over monotube shocks and stabilizer bars front and rear. The upper control arms are identical at all four wheels and are made with an advanced rheo-cast process that allows the complexity of form associated with casting while retaining the strength of forging. The metal, heated to just below its melting point, is the consistency of butter when it is injected into a mold at high pressure. Pressure is maintained as the part cures, preventing porosity in the final product for exceptional strength." You could almost laugh at that in retrospect because the Ford GT of '05 had to be recalled when they found a crack in one of the squish-cast arms.

Ford goes on: "The steering rack also is borrowed from the Ford GT, with a few modifications. The steering, like the Ford GT's, draws on Ford's global driving dynamics DNA introduced with the Ford Focus' industry-leading steering column featuring light efforts, low friction and high stiffness. Braces between the front shock towers and below the isolated engine mounts improve torsional rigidity and aid steering response."

 The Engine: Ford wrote: "The heart of any supercar is its engine, and the Ford Shelby GR-1 concept does not disappoint.

Inspired by the biggest, baddest engine of them all – the renowned 427 – Ford engineers created a new aluminum-block V-10 to power last year's Ford Shelby Cobra concept. This 390 cubic inch, 6.4-liter engine, reprised for service in the Shelby GR-1 concept, is adapted from Ford's MOD engine family. It delivers the rush of raw power – with 605 horsepower and 501 foot-pounds of torque – associated with that big 1960s V-8 powerplant without the aid of supercharging or turbocharging.

This combination of brute force and thorough engineering has created a rarity in the world of auto shows – a concept car that can actually do, rather than merely promise, 0-60 in under four seconds, and would easily exceed 200 mph if not electronically limited.

For approximately three years, the Ford powertrain team had been working on an all-aluminum V-10 targeted at ultimate, naturally aspirated performance. One also has to conclude they had an eye on the Viper which is also powered by a V-10.

   They were able to use the same Ricardo transaxle as the Ford GT, by having the six-speed manual transmission packaged in a way that would not compromise the occupant footwells. "One of the unique solutions we delivered for the GR-1 concept was the design, engineering and development of a torque-tube driveline, which allows placement of the transmission in the rear of the car behind the occupant zones," said Rumpel.

The rear-mounted six-speed transaxle is identical to the high-performance unit in the Ford GT, with an integral limited-slip differential to drive the rear wheels. Based on the engine's 7,500-rpm redline and the wide drive ratios, this Ford Shelby GR-1 concept , Ford claimed, had a theoretical top speed of around 200 mph, just short of the 207 mph claimed for the Ford GT at the Nardo track in Italy, although for the GR-1 it was electronically limited – just as it was in the production Ford GT.

Why was the transaxle used instead of an engine connected directly to the trans? Because of the desire to fit  a large engine into a compact coupe while leaving enough room for the driver's legs and feet. With a conventional transmission mated to the back of the engine, the tradeoff between hood length and passenger room often makes for a cramped footwell and dramatically offset pedals.

Mounting the transmission in the rear helped to more evenly distribute the vehicle's weight and increased the footwell area from 16.5 inches to 21.7 inches, resulting in almost three inches more legroom than in similar performance vehicles.

The legroom-saving torque-tube driveshaft runs at engine speed, considerably faster than typical driveshafts mounted to rear of the transmission. The spinning inner shaft is supported within a stationary outer tube that stabilizes the engine and transmission in bending and in torsion. The inner shaft taps crankshaft torque via a twin-disc, small-diameter clutch mounted at the rear of the engine.

Computer-aided design was essential in helping the first prototype come together smoothly.

"Because they spin so much faster than driveshafts, these torque tubes can be a challenge to execute properly in terms of vibration," says Rumpel. "Using our electronic tools, we optimized the location of the driveshaft support bearings, and it ran smoothly on the very first try. This type of modern engineering tool gives us a development advantage that pioneers like Carroll Shelby could only dream about."

The Daytona coupe had only one fuel filter but similar to the Ford GT concept, they had twin fuel fillers  on the GR-1, exiting the bodywork just aft of each sideview window and mid-way up the rear quarter panel bodywork. These racing-inspired devices feed two individual 10-gallon capacity fuel tanks that reside inside the structural chassis directly behind the passenger compartment.

The battery was also relocated to the rear of the vehicle, deep inside the luggage compartment, further aiding vehicle weight distribution and better shielding the battery package from the intense heat of the engine compartment. A new cooling system, evolved from the Shelby Cobra concept, includes a unique hood with twin portals to feed air into the engine compartment.
POWERFUL BRAKES The team set braking distance targets comparable with today's best supercars, and turned to the Ford GT braking system for suitable components.

Brembo "monoblock" one-piece aluminum brake calipers with four pistons each grab cross-drilled, vented discs at all four wheels. The discs are a massive 14 inches in front and 13.2 inches in the rear, for fade-free stopping power. Brake balance is biased slightly to the front wheels to aid stability.

For packaging reasons, the team devised a novel offset actuation linkage for the brake booster and master cylinder, so the brake pedal can be placed in a normal position even though its hardware is off to the side of the engine bay. The kinematic linkage concept for the remote booster actuation was an idea borrowed from the European Ford Mondeo.

"The unique remote booster had to be just right so you can slow the car in a linear and proportional way. This means the pedal effort and travel are proportional to the vehicle deceleration rate, which is especially important in high-performance sports cars," said Rumpel.

The one-piece, 12-spoke BBS wheels are fitted with Goodyear Z-rated racing slicks. The fronts are 275/40R-19 while the rears are 345/35R-19.

"The ultimate litmus test for an engineer is in the hardware. You can do all the CAD work and virtual work that you want, but it really doesn't mean very much until you build it and drive it and show you've delivered the product as planned."
– Mark Bergdahl, Supervisor, Chassis and Powertrain Systems Architecture, Ford Advanced Product Creation

The key to occupant safety in a vehicle begins with a strong, solid structure. While weight and vehicle mass have long been considered an advantage for crash safety, neither are desired attributes in a high-performance supercar. Thankfully, the use of modern materials and computer-aided engineering have provided the Ford Shelby GR-1 concept with a spaceframe that is both lightweight and rigid.

Why wasn't the car put into production? First of all, Ford was broke at the time and didn't have the money. Secondly, they had to see how the Ford GT worked out--if it met its sales targets Thirdly, though Chrysler showed a more svelte two seater front engined sports coupe on a Viper chassis called the Firepower, they made no hints that it was slated for production so Ford figured they didn't have to get the GR-1 ready to fight a plusher Chrysler supercar if Chrysler wasn't really going to do it. Also there was still the problem of the Aston Martins. For every GR-1 sold would that mean one less Aston would be sold?

Ford has talked recently of making a new supercar so we'll have to see if the GR-1 can come back in a more ready-to-produce way.


  1. not fun if it gets dirty och get a scratch

  2. that is one gorgeous car...

  3. Shiny!:P , Would love to take this for a spin.

  4. It's beautiful. Such a great line...

  5. That, is now on my wishlist. Simply beautiful design. If I had the money, I would probably spend 2.2 mil on a machine like that if it meant I'd get the first one off the production line.

  6. oh the things id do for the possession of that car...

  7. oh my word..
    you need a post on gettng the dibble out of my keyboard.
    that's a beautiful car. i still have huge amounts of love for the 1,005 odd hp produced by the Bugatti Veyron though ;D

  8. why do concept cars never become affordable?!

  9. That thing looks beautiful. No idea on the price?

  10. Cool car, better post! Really informative, keep it up!