In my commentary on Jim Pearson's wonderful recreation of the historic
Dundrod circuit, I noted the startling discrepancy between Jim's lap time in
the included replay (3:28) and Stirling Moss' best lap lap in the
Mercedes-Benz 300SLR (4:48) in the '55 Tourist Trophy. (According to
Guinness, Mike Hawthorn holds the absolute sports-car record at 4:42 in a
D-Type Jag.) By highlighting the difference, I didn't mean to impugn the
accuracy of Jim's version of this circuit - it reeks of veracity. No one
ever got that resonant a "look and feel" without doing his homework.
Rather, I believe the difference can be explained by three factors.
1. The changes to the track between the real-world layout that Moss drove in
'55 and Jim's version, which simulates the layout used from '65 to the
present for motorbike races.
2. The differences between the 300SLR and almost any 1967 Formula 1 machine,
but particularly the Brabham BT24. According to this site:
the 300SLR weighed 1984 lbs. and was powered by a 310-hp straight eight, or
6.4 lbs/hp. The '67 BT24, according to Papy, weighed 1105 lbs. and was
powered by a 350-hp V8, or 3.16 lbs/hp, i.e., about twice the scat of the
Merc.
Moreover, the 300SLR had drum brakes (albeit really huge ones, and unsprung,
too, as I remember) vs. the Brab's 4-wheel discs, and most importantly, the
older car was on incredibly narrow rims (prob. 5-in.) vs. the F1 car's much
wider rims (prob. twice as wide). Racing tire technology had made leaps &
bounds in the intervening dozen years as well.
3. Driving technique. If you watch movies of 1950s sports car enduros, you
see that the drivers of the day did not fling their cars around with nearly
as much abandon as did "Black Jack" Brabham (an old dirt-track meister) did
in the 60s, much less with as much verve as Jim does in his replay. While
some of the early drivers may have taken hairy chances at short, wide tracks
like Silverstone and Sebring, they were much more cautious at long, narrow
venues like the Ring, the Targa Florio, and Dundrod. I mean, my God, they
had to complete 84 laps (623 miles, over 1000 k's) of the blantantly lethal
Ulster circuit.
Anyway, all of which is by way of saying that I believe Jim Pearson's
Dundrod is as accurate as a brass ruler.
--Steve Smith
