The Cosworth is tuned for speed with an increased power in high rpm. Generaly these motors have less power at low rpm and must be used at high rpm to get the benefit of the tuning.
In the case of the Cosworth the losses at low rpm are well limited, but the torque graph has a hole between 4200 and 4800 rpm. Increasing of torque and power rocket after 5000 rpm.
Compared to the standard Duratec 145 Bhp :
from 2000 to 2700 -4 Bhp -10%
from 2700 to 3000 +0,8 Bhp +1%
from 3000 to 3900 +3,8 Bhp +5%
from 4200 to 4800 -7 Bhp -6%
at 5500 +23 Bhp +16%
at 6000 +43 Bhp +30%
et 6500 +97 Bhp the standard Duratec has only 103 Bhp at this rpm, power decreasing dramaticaly after 6000 rpm.
The AR P4 seems to have the same Mazda gearbox than the PLUS 4 (to be confirmed) with a 3,9:1 rear axle but larger wheel 16 " vs 15 ". They have quite the same speed at 1000 rpm :
in 5th gear :
AR P4 : 38,7 km/h (24,2 mph)
PLUS 4 Mazda gearbox 38,2 km/h (23,9 mph)
PLUS 4 2005 40,5 km/h (25,1 mph) Ford gearbox
Real benefits come above 5000 rpm.
Last edited by CBY; 07/03/16 09:49 AM.
