scoooby slayer

iTrader: (4)

hi was just wondering what speeds in each gear people are getting from 2wd saphs on standard drivetrain when hitting the limiter?

rapidcossie

standard size wheels amd tyres?

tabetha

Road speed at given RPM =
60 X Engine RPM / Divided by Wheel Revs(mile) X Axle Ratio X Gearbox RATIO.
So that is, 60 X 6500(rpm) / 897X3.64XGearbox ratio.
I don't have the gearbox ratio(to hand) so I looked in the FORD booklet instead.
Cossie max speed is as stated
1st = 40
2nd = 62
3rd = 89
4th = 119
5th = 149
This is what ford say in the booklet that came with the cossie, so if inaccurate down to them.
tabetha

scoooby slayer

iTrader: (4)

as always your a fountain of knowledge mate thank you.
im gettin 105 mph in 3rd and my speedo isnt far out, my rev clocks saying 6500 rpm so really im probably over 7000 rpm anyway.
thanks mate

tabetha

"fountain of knowledge", no I just looked in the booky.
tabetha

2001ode

iTrader: (1)

Just a little change :
60 x RPM x wheel rev / (axle ratio x gear ratio)

Regards
Claude

tabetha

Beg to differ matey but you are incorrect.
It is as I said, example,

60 X 5000(rpm) = 300,000
897(wheel revs/mile) X 3.62(diff ratio) X 0.73 Gear ratio(top) = 2370.4122
= 300,000 / 2370.4122 = 126.56
NB this is just an example not necessarily applicable to the cossie.
tabetha

scoooby slayer

iTrader: (4)

just got gearbox ratio and added up. your right tabetha.
at 7500 rpm 1st 43 , 2nd 71 , 3rd 103 , 4th 138 and 5th 173
my rev clock must be showing 6500 rpm when its really 7500 rpm.
i think il stick to no higher than 6000 rpm on me rev clock dont wana kill the old girl
thanks people

tabetha

They have rev elimiters(ecu), but safe to 8000 all day long anyway!!
tabetha

scoooby slayer

iTrader: (4)

ive just done the ratios for a tremec t56 at 7500 rpm would be 1st 46, 2nd 66, 3rd 96, 4th 138, 5th 173 and 6th 223.
does anyone know if speedo would be correct if this box fitted ?

tabetha

So long as the drive(cable) turns at 1000 times a mile then it is correct.
tabetha