SR9 Registry

In early 2005 Radical Sportscars had built nearly 450 race cars and was producing four different models, including the newly released SR8 which was joining the Clubsport/Prosport, SR3, and SR4.  At that time the SR4 had been voted “Track Day car of the year” by Evo Magazine, and the new high downforce SR8 Sports racer was described by Autocar Magazine as “The greatest track car in Creation”.   Then on March 15^th, 2005, Radical announced its intentions to produce a car to race in the American and European Le Mans P2 series and the 24 hours of Le Mans.  Well known Le Mans car designer Peter Elleray was hired to design the car for Radical and to leveraged much of what he had learned designing the Le Mans-winning Bentley prototypes.  Radical’s initial concept was to make a “competitive and cost effective” Le Mans P2 Prototype that used an aluminum-carbon composite hybrid monocoque chassis and a 3.0L 525 hp version of the Radical / Powertec V8 engine.  However, as the design progressed Radical decided, with encouragement from Peter Elleray, to change the focus of the program to a class winning car with a full carbon monocoque chassis and a drivetrain with proven Le Mans reliability.   Radical teamed up with Advanced Engine Research (AER) and Judd Engine Developments LTD to produce the engines, and Ricardo to supply their reliable six speed sequential gearboxes that were used by Audi and other LMP teams.  The SR9 was initially designed to run the AER 2-liter (1995cc) turbo-charged four-cylinder engine that produced 530 bhp and 457.3 ft lbs. Torque.  But the lead customer for the SR9 was Rollcentre Racing who had an agreement with Judd Engine Development, so Radical redesigned the rear of the car to offer customers a naturally aspirated engine option in the Judd 3.4L (3397cc) flat plane V8 producing 530 bhp and 350 ft lbs. of torque.  

In the original announcement the cost target for the SR9 was set at £120,000 to £130,000 with the engine and ancillaries costing another £30,000.  The actual cost of the SR9 ended up being closer £190,000 for a rolling chassis and transmission, which was about half of the cost of the other LMP2 options.  The Powertec AER engine cost £64,000  with £13,500 rebuild cost every 3,000 to 5,000 km.

A total of six SR9’s were built.  About two months after the topic of building “Competitive and cost effective” Le Mans P2 Prototype first came up Radical announced their plans to design and build the SR9. Just 12 months after the announcement, SR9 chassis number 1 pulled out on the track for its first test, and two months after that the car competed at 24 hours of Le Mans for the first time.  SR9’s competed in the Le Mans 24 hour race five times with the best finishes being 5^th in class in 2006 and 6^th in class in 2010