In order to finalize this analysis with the datas of cerealsurfer and the curve provided by Peter.
3 comparisons :
(A) - 2005 PLUS 4 standard gear box and standard 142 BHP Duratec motor
(B) – standard gear box and 180 BHP tuned motor with throttle bodies and a Librands exhaust (curve given by Peter)
(C) – 2005 PLUS 4 with standard motor 142 BHP and race ratios given by cerealsurfer
rear axle 4,1:1
5th 0,87:1 final 3,57:1
4th 1:1 final 4,1:1
All the 3 configurations use the standard tyres : 195*60 R15
The available power with the race gear (C) and the standard motor below 160 km/h (~100 mph) is better than with the tuned 180 BHP motor and may allow better accelerations.
The tuned 180 BHP motor with the standard box is better over 160 km/h.
In the standard configuration, with 5th gear you get only 125 bhp @ 190 km/h which is the maximum speed. With the race gear box you get 141 bhp which is the maximum of the power curve. You can use all the power area.
At maximun rpm, 6675 rpm with 5th gear the theorical speed will be :
standard gearbox : 270 km/h
race gearbox : 217 km/h
Instead of a tuned motor, Morgan must propose a short gearbox.
I have a Ford PUMA and the 5th gear ratio is very close to the race box : 130 km/h @ 4000 rpm.
