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be very accurate when used to predict the performance and handling

improvements of the Daytona.

DAYTONA AERODYNAMIC DEVELOPMENT

After the 5 MPH minimum lap speed improvement had been established

as the major goal o l-tl the Daytona program, the areas to be improved on

the 1969 race car and the constraints imposed by various stock car

associations were investigated. It had been well established by pre­

vious track tests that to increase lap speeds by 1 MPH in the 190 to

200 MPH lap speed range required an additional 17 horsepower and im­

proved handling. Approximately half of the horsepower required is used

to overcome aerodynami n drag whil c o the remainder is used to overcome

rolling resistance and drive train losses. Rolling resistance is

normally a small portion of the total horsepower requirement at high

c n peeds but in the corners of closed circuit tracks becomes of major

importance. This is illustrated by the fact that the Daytona is cap­

able of a top speed of over 220 MPH although this speed cannot be real­

ized on today's tracks.

Preliminary calculations showed that a 15% drag reduction from the

level of the 1969 race Charger was required to gain a 5 MPH lap speed

increase. The 1969 race car was, to begin with, a better car aero-

dyanmically than the standard 1969 Charger; the grille and backlight

areas were significantly improved from drag standpoint and a front un-

dernose 72 poiler was used to reduce front end lift. Although the front

treatment of the 1969 car was improved by a different grille treat­
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ment, this area was 7. till considered a high drag region capable of
being significantly improved. In addition, the abrupt windshield

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