WHICH IS THE FASTEST ROAD CAR?
I am writing to yt at with regard to your recent article entitled ” Which is the Fastest Road Car ? ” In the course of your article you say ” The Conan Doyle Brothers used to put forward a rathcr special 38/250 Mercedes-Benz with a large supercharger, but no figures are available, and standard examples have never equalled Lycett’s Bentley.”
Perhaps I may be allowed to correct this somewhat belittling impression of the car by giving one or two facts and figures. The car was not, as you seem to think, a big blower S.S.K., but a S.S.K.L. fitted with the ” elephant ” blower. The difference between these two models is considerable, the latter having a lighter chassis, a crankshaft of entirely different and much lighter metal, a camshaft with a much higher lift, different valves, etc., and a supercharger blowing at 12 lb., compared with the 10 lb. of the ” Big ” and the 8i lb. of the standard
supercharger. This car developed approximately 300 b.h.p. Only six of the S.S.K.L. models were ever made. Caracciola had two, Von Stuck had one, Von Brauchitsch had one, Otto Merz had one, and we had the sixth, which was previously in Scandinavia, and
which is the only one to have been in this country. As regards the performance of this model, the late Sir Henry Birkin declared that it was the only sports-car in the world which his 4i-litre blower Bentley
could not hold. I believe this remark was made after Caracciola in a S.S.K.L. had twice lapped Birkin’s Bentley at Phoenix Park in, I think, 1930.
Caracciola won that race from scratch, doing 187 m.p.h. on the straight in pouring rain, the car being fitted with full equipment. The same year, he won the Avus race in a S.S.K.L. averaging 119 m.p.h. for the 183 miles, in the course of which race this model officially exceeded 147 m.p.h.
This car was identical to our machine, with the exception of a slight difference in the back axle ratio.
The following year, Von Brauchitsch won the Avus race in the model, fitted with a special body. He averaged over 121 m.p.h. for the race, during which he was holding a speed of 156 m.p.h., and in the course of which he beat the monopost° Alfas. To conclude, with regard to the performance of our old Car, its acceleration was phenomenal, but, unfortunately, I have no exact figures. Its third gear performance was exceptional, for it was
timed on the track at 102 m.p.h. in third gear over a measured distance.
With regard to its maximum speed Mercedes Racing Expert estimated it at 144 m.p.h. in stripped form, the difference between this and the speed achieved by Caracciola at Avus being explained by the slight difference in axle ratio. I may be mistaken, but no figures which are mentioned in your article appear to exceed the performance of our S.S.K.L. I am, Yours etc.,
DEN-is P. S. CONAN DOYLE. London, W.1.