In 1990, an agreement was reached between entrepreneur John Mangoletsi and the family of British Racing Motors (BRM) founder Alfred Owen, who had retained the naming rights to the company. The use of the BRM name would help Mangoletsi's project gain sponsorship and funding by appearing as a manufacturer entry against the likes of Toyota, Peugeot and Mazda in the World Sportscar Championship.
With the backing of BRM, Mangoletsi turned to former Zakspeed chief engineer Paul Brown to design the car. Brown produced a conventional carbon composite monocoque Group C chassis, which was well regarded by those who drove it for its excellent handling. The composite chassis of the car was constructed for the team by the engineering firm Courtaulds and finished in a metallic british racing green with BRM's traditional orange nose. The engine was designed by Graham Dale-Jones and built by Terry Hoyle's JHS company using a block derived from the Weslake V12 Grand Prix unit. It was branded as a 'BRM'. Claimed output was 626 hp (467 kW) at 11300 rpm but it proved to be uncompetitive and unreliable. Dale-Jones virtually redesigned the V12 which actually exceeded its performance targets and further validation work on the engine was carried out by Ricardo Engineering. A model of the BRM P351 was exhibited at the Autosport Racing Car Show in January 1991 and the complete car was unveiled in London’s Science Museum in November of 1991.
The car had a brief test at Snetterton, where no more than 30 laps were completed. The BRM P351 debuted at the 1992 500km of Silverstone, the second round of the World Sportscar Championship. The drivers assigned were Wayne Taylor and Harri Toivonen. After problems in qualifying with a battery, the car was forced to take the last qualifying position. The car suffered more problems, and did not take the race start. The team moved next to the 24 Hours of Le Mans, where Richard Jones was added to the driver line-up. The car qualified 23rd out of 29 entries. However, the car suffered transmission failure after twenty laps, the first car out of the race.
In an attempt to find sponsorship, the team transferred the P351 to the United States to participate in an IMSA Camel GT round at Watkins Glen International. Although the team had checked in advance that the chassis was compliant with IMSA regulations, the track at Watkins Glen was not as smooth as the European tracks it had previously raced on and BRM were forced to raise the ride height. This made the car taller than IMSA regulations allowed. At the suggestion of designer Paul Brown, the car's tall roof-mounted intake was removed with a Sawzall, split down the middle and remounted with the two halves of the intake on their sides, forming a new intake with the same cross-section and lowering the car enough to meet the regulations. Unfortunately the car still suffered from its poor reliability record, succumbing to electrical failure after a mere five laps.
After these attempts, money for the project was beginning to run out as sponsorship was not forthcoming. The team returned the P351 to Europe and entered the next World Sportscar Championship round at Donington Park, but never appeared. After this, the team pulled out of the World Sportscar Championship and the team folded. To satisfy the team and all the industry supporters, team manager Ian Dawson carried out a 1,000-mile test to prove the true capabilities of the P351. A new camshaft profile was developed to address valve spring surge between 10,500 and 11,000 rpm. By this time all the relatively minor problems that had been encountered, primarily with bought-in ancillary components, had been resolved and the car ran faultlessly. The BRM was returned to Rubery Owen who kept it in storage for three years.
In 1996, the stored P351 chassis was bought by Keith Wiggins, founder of Pacific Racing. Following Pacific's attempts at Formula One and Formula 3000, Wiggins decided to enter the team in sports car racing, planning on the new International Sportscar Racing Series that would debut in 1997. The car was heavily modified with the help of Pilbeam Racing Designs and became known as the BRM P301. The car's roof was removed to create an open cockpit design, requiring a rollbar. The Weslake V12 was replaced with a twin-turbocharged Nissan 3.0L V6, requiring two inlets to the upper bodywork for the turbochargers.
The P301 debuted at the opening ISRS round at Donington Park, being driven by Franz Konrad, Richard Dean and Wido Rössler. The car qualified 6th out of nine entries, but failed to start the race due to electrical problems. The team then focused on the 24 Hours of Le Mans, with a driver lineup of Eliseo Salazar, Jésus Pareja and Harri Toivonen. The P301 set the 34th fastest time out of 48 entries, placing 19th on the grid. However, the car suffered engine problems and dropped out after 6 laps. In 1998, the P301 entered the ISRS round at Misano with Tim Sugden and Grant Orbell, qualifying 9th out of 24 entries. It failed to finish after 4 laps. The car then failed to start at Donington, marking the final race for the P301 chassis. The BRM P301 thus ended its career similarly to how the P351 had begun.