Running flat-out into history:
Racing Beat's second-generation Mazda RX-7 shatters Class C GT land speed record at Bonneville

Speedweek at Bonneville Salt Flats is the ultimate test of performance in its purest form. The object of this incendiary three and a half days is simple - run flat-out on the flats by standing on the gas until a record falls, your machine gives, or the run is over.

In 1986, Racing Beat chief engineer Jim Mederer would become the visionary behind a record-shattering campaign at Bonneville-and a historic new line-item on Mazda Motorsports' CV of speed. Mederer's team started with a 1986 Mazda RX-7 and began its transformation with a turbo charged 13B Two Rotor. The team moved on to execute blistering tuning modifications and chassis alterations that would propel this low-slung speedship into history.

The Racing Beat team exceeded its own dedication to performance excellence, starting with the powertrain. The team massaged basic powerplant elements similar to RX-7 stock components to boost its output to monumental levels. With two rotors and 80 cubic inches, this historic RX-7's completed rotary produced 530 horsepower at 8500 rpm with 1 atmosphere (14.7 psi) of boost.

Mederer's team complemented the monstrous output of the powerplant with an all-new drivetrain. With simple design and a reputation for exceptional reliability, Weismann Transmissions manufactured a 5-speed racing gearbox with no synchros, face-dog engagement, and dry-sump lubrication. The Racing Beat team used only stock suspension parts to lower the front end, leaving the rear suspension untouched. Goodyear responded to the project with specially made tires that boosted both speed and safety quotient.

Additional mods made for the final burn would include:

  • Racing Beat-designed rear suspension with five tubular links per side between fixed points on the chassis
  • Porsche 911 stub-axle carriers
  • A Stock Car Products center section supporting a 5" pinion gear
  • Custom side plates machined by Racing Beat with Summers Brothers spool drive
  • Bosch Kugelfischer mechanical fuel injection pump
  • Hitachi twin turbos
  • Arrow Gear Company cogs with a simple spiral bevel gearset at 2.00:1 ratio

Following checkout passes and qualifying runs that produced shake out bugs and an eventual engine transplant, the salt dust finally cleared for Mederer's team. When the candle was lit for the official run at the books, the RX-7 launched across the flats at a glorious 8550 rpm-that's 244.132 mph pure ground speed. After two runs averaging an eye-watering 238.442 mph, the Racing Beat team had forever earned its place in the stratosphere of land speed records - and performance-engineering excellence.