George Suennen's 200mph Open Road Racing 928
Open Road Racing (ORR) is a form of high speed racing practiced in the USA . Normally public roads are closed to all but the competitors and the courses are anything from 50 to 100 miles in length. Courses exist in Nevada , Texas and Nebraska .
There are a series of classes in which to run, ranging from 85 to 180mph average speeds plus Unlimited. For the Street Stock class, competitors have to hold a driver's license, the car fitted with a fire extinguisher system, and helmets for both occupants. For the higher speed classes the requirements become much more demanding.
There are limits on both maximum and minimum speeds allowed in each class, enforced by hidden speed traps, so very precise control of speeds are required. Cars usually have a navigator to monitor progress and inform the driver to change speed as needed.
928s have been well represented in this form of racing over the last dozen years, ranging from standard 928s running in the Street Stock class up to highly modified cars in the Super Sport (155-180mph average speed) and Unlimited classes.
George Suennen has been competing in ORR for twelve years. In that time his 928 has changed from a fairly stock 1990 S4 automatic to a supercharged 5 litre full race car putting out 500 rear wheel horsepower ! In the last few years he has become one of the small group of elite 928 drivers to achieve over 200mph through the speed traps.
His engine uses a Vortech V1 T-trim centrifugal supercharger running at 15psi, parts supplied by Tim Murphy. Water/methanol injection is also incorporated. The engine was built by Jim Morton, Bill Ball, Dennis Kao and himself in Jim's backyard in Walnut Creek , with much support from other Rennlist experts.
The engine uses a JDSPorsche SMAF to ensure accurate fuelling at these high power levels, and the car SharkTuned by Bill Ball. One problem is that course like the Silver State Classic Challenge in Nebraska is run at 6,000ft altitude. This requires some retuning of fuelling compared to sea level, as safety margins of air/fuel mixture become much more critical when running sustained high speeds.
Bill Ball Sharktuning George's car on the dyno
The amount of development of his car should not be underestimated, for example the fuel system had to be completely redesigned, also incorporating a fuel cell as required for running in the Super Sports classes.
Although in August 2008 George registered 199 mph at the Pony Express 130 Open Road Race, for various reasons it was at the May 2012 at the Nevada ORR event that George's car first hit 200mph through the speed trap in, followed by another 200mph run at the Silver State Classic Challenge in September later that year. In the latter event he was entered in the 170mph average speed class for which he needed to run at 180mph for the majority of the course, allowing for some reduction of speed in the turns. He averaged170.2354 mph average for a 2nd place, a terrific achievement as he did not have a navigator on board.
George says of the SharkTuner – “ I want to thank you again for developing such a great tool for tuning the 928. Without it, I doubt I could have done so well at the Nevada Open Road Challenge earlier this month.”
At the Nevada Open Road Challenge in May 2013, George entered the 170mph class which he won at an average speed of 170.609mph. Partnered by navigator Van Bagley, they were offically timed through the speed trap at 210mph.
All photographs copyright George Suennen
This text © JDSPorsche 2012