Cadillac Northstar LMP-02 Chassis And Engine Specs
Technical Specifications: Cadillac Northstar LMP 02
Cadillac Northstar LMP-02 Chassis
Construction: Carbon fiber monocoque with aluminum honeycomb core Weight: 900 kilograms (1984 lbs.)
Length: 465 cm. (193 in,)
Width: 200 cm. (78.75 in)
Height:102 cm. (40.15 in.)
Bodywork: Carbon and Kevlar with Nomex honeycomb Suspension: Double wishbone front and rear with pushrods Dampers: 4-way adjustable gas-filled
Brakes: AP 6 piston monoblock calipers - carbon fiber discs Steering: KYB electric power steering
Wheels: BBS one-piece forged magnesium custom designed for Cadillac Front diameter: 18 in. width: 13.5 in.
Rear diameter:18 in. width: 15 in.
Tires: Michelin Pilot
Gearbox: Xtrac 6-speed sequential
Clutch: AP four disc carbon diameter 5.5 in. (160 mm) Fuel cell: Capacity: 90 liter (23.7 gallon)
Data Acquisition:Pi Sigma with Bosch telemetry
Cadillac Northstar Engine - Twin Turbo
Type:Twin turbocharged and intercooled 180 degree V8 Displacement: 4000 cc (4.0 Liter - 244 cu. In.) Bore x Stroke: 93 mm. (3.66 in.) x 73.4 mm. (2.89 in.)
Lubrication: Dry sump with oil to water heat exchanger Fuel system: Bosch
Intercoolers: Secan air-to-air
Restrictors:Twin 32.4 mm diameter
Maximum rpm: 7500
Brake horsepower: 600
Top speed: 200 mph (322 kph) in LeMans trim
Cadillac LMP 02 Technical Insights: Chassis Design And Development
SEBRING, Fla. - As Cadillac celebrates its 100th birthday in 2002, one of the first presents to be unwrapped is the all-new Cadillac Northstar Le Mans Prototype (LMP). With an aerodynamic new body design, an updated engine package and a performance-driven team, the second-generation Cadillac LMP 02 represents a bold break from the past for young Team Cadillac.
CADILLAC LAUNCHES NEW NORTHSTAR LMP IN CENTENNIAL YEAR
"Very seldom in racing can you talk about a program in its third year and say that you have an all-new race car, but that is exactly the case with the Cadillac LMP 02," said Herb Fishel, executive director of GM Racing. "The Cadillac LMP 02 marks a new beginning for Team Cadillac with a state-of-the-art race car
"We recognize that Cadillac faces formidable and experienced opponents in the top tier of international endurance racing," Fishel noted. "Now after seeing what Team Cadillac has created, we are optimistic that the 2002 Cadillac LMP will be a credible contender in this fiercely competitive arena. And once you can race side-by-side with the competition, you can begin to look forward to beating them."
INTERNATIONAL TEAM CREATED CADILLAC LMP 02
Designed under the direction of GM Racing by Nigel Stroud, the Cadillac LMP's carbon fiber monocoque chassis and suspension components were fabricated in Brackley, England, and assembled at the team's headquarters near Atlanta. An extensive testing program is planned leading up the 24 Hours of Le Mans on June 15-16, 2002. The Cadillac LMP 02 will also compete in selected American Le Mans Series events in North America.
"The new Cadillac LMP 02 is the culmination of a deliberate step-by-step process," said Jeff Kettman, GM Racing Cadillac LMP program manager. "In the first year of the program, we learned about the level of competition we faced. In the second year, we focused on collecting data and accumulating experience while racing a highly modified LMP 01 chassis. Now in the third year of this program, we are introducing the new Cadillac Northstar LMP 02 - a car that incorporates the lessons we have learned and embodies the knowledge we have gained."
DESIGN TEAM EMPLOYED GM'S TECHNICAL RESOURCES FOR EFFICIENCY AND SPEED
"Team Cadillac made use of General Motors resources throughout the design phase of the project," Kettman continued. "Computer simulations allowed us to refine the vehicle's aerodynamics and analyze suspension geometry rapidly. This digital data stream, combined with the trackside data from Le Mans and North American race circuits, enabled Team Cadillac to create an all-new car quickly and efficiently."
The design team utilized the full range of sophisticated tools that are now available to race car constructors: computer-aided design and manufacturing (CAD/CAM), computational fluid dynamics (CFD), finite element analysis (FEA), and three-dimensional solid modeling. Wind tunnel and seven-post tests then validated the Cadillac's performance under carefully controlled conditions.
NEW CHASSIS DESIGNED ENTIRELY ON COMPUTER
The cornerstone of the Cadillac LMP 02 program is a new carbon fiber chassis - designed not on a clean sheet of paper, but on a glowing computer screen.
"While the series rules define many of the car's dimensions, we were able to make significant changes to the chassis within these parameters," said Nigel Stroud. "For example, the move to a shorter wheelbase improves the Cadillac LMP's aerodynamic performance by making the chassis less sensitive to pitch. This results in an overall improvement in stability over the previous car."
SHORTER WHEELBASE PRODUCES IMPROVED STABILITY
The Cadillac LMP 02's high nose directs airflow under the car while respecting the LMP rules that require a flat bottom between the front and rear wheels. This flat surface can, however, generate significant downforce through ground effect - the interaction between the moving vehicle and the fixed track surface. By shortening the wheelbase, undesirable changes in the vehicle's attitude are minimized, allowing the flat bottom to maintain a positive rake angle and produce consistent aero loads. Wind tunnel tests have demonstrated substantial improvements in both lift and drag over the first-generation LMP 01.
The Cadillac LMP design team explored a variety of imaginative body and chassis layouts before finally selecting a shape that is familiar to road racing fans.
"We looked at several concepts that really pushed the limits, but none satisfied all of the requirements for downforce, cooling and packaging simultaneously," Stroud said.
NEW CONSTRUCTION METHOD USED IN CADILLAC LMP MONOCOQUE
"Advances were made in the construction of the monocoque by using a different method of bonding the two halves together," he continued. "The side-mounted radiators employ water-to-oil heat exchangers to cool the gearbox, which eliminates the aerodynamic penalty of a separate air-to-oil cooler for the transmission. This system also stabilizes the gearbox oil temperature, especially at the beginning of a race when the lubricant is preheated by the engine coolant."
Safety considerations also figured prominently in the design of the Cadillac LMP 02. A Formula 1-style cockpit surrounds the driver while head restraints molded from shock-absorbing foam cradle the helmet's back and sides. An innovative pedal box assembly provides an extra measure of protection for the driver's lower extremities.
INNOVATIVE PEDAL BOX ENHANCES DRIVER SAFETY
"The monocoque is the primary survival cell," Stroud explained. "Inside of that is a secondary cell to protect the driver's feet. This 'box within a box' also offers the advantage of a fully adjustable pedal assembly to accommodate different drivers."
The double wishbone suspension employs F1-style cast stainless steel uprights that mount six-piston monoblock brake calipers and carbon fiber discs. The power steering is electronically assisted.
"We have made a large number of small changes in the car that we believe will add up to a substantial overall improvement in Team Cadillac's on-track performance," Stroud predicted. "It comes down to getting the details right in order to produce a great car at the end."
It is said that a journey of a thousand miles begins with a single step. With the introduction of the Cadillac LMP 02, Team Cadillac has taken many steps in its quest to reach a higher level of success - and there are many more steps ahead on the long road to Le Mans.