All four Japanese makers dabbled with turbo motorcycles in the early 1980s, but custom builders have remained shy. In the US, notable exceptions are the Del Prado brothers—and Icon Motosport, who turbocharged a pair of Triumph Daytonas for a Motorcycle vs. Car Drift Battle film.
So when we heard about the BMW Turbo Salt Racer from Kingston Custom, our ears pricked up. Tales of blown BMW racers from the inter-War years are legion, but we’d never heard of a blown airhead.
Turns out there’s a low-key turbo scene amongst touring BMW owners in Europe, mostly driven by the kit specialist RB Racing.
“But my research on the internet wasn’t too successful. Turbocharged BMWs were something which began and ended at the beginning of the 80s.”
Dirk tracked down an R100 RS with a Stütz turbo kit that boosted it to 100 horsepower. “I could hardly believe my luck. It was probably the only one that has ever been offered for sale, so I bought it immediately.”
Then he located an R100/7, and bolted on the plumbing from a Porsche 924 Turbo. (It’s not the first time Dirk has grafted Porsche bits onto a motorcycle. A couple of years ago, he built a motor with a Porsche 930 top end and a Yamaha SR500 bottom end.)
To cope with the pressure, the valves are new, and the cylinder heads have been ported. “The crankshaft, flywheel and clutch were also too heavy,” says Dirk, “So I’ve drilled and lathed them to reduce weight.”
The 40mm Bing carburetor has been bored up to 41mm and modified to operate with the turbocharger and the increased petrol pump pressure. The engine now puts out 126 horsepower at 8500 rpm (93kW) when running 1.25 bar of pressure.
The next step was to add the retro style that Kingston is noted for. The hoses, wires and cables have disappeared, and the starter motor and fuel pump discreetly relocated.
Just ahead of the Fehling clipons is a tiny bubble visor to protect the modern-style headlight.
Maybe it’s time to revisit the whole motorcycles-with-turbochargers thing?