Hi John,
It's not to difficult to work this out yourself - you need to know the Diff ratio and the rolling circumference of you rear wheels. Diff ratio is easy
- just find the Casing number and look up the listings - should be 4.11:1.
For the rolling circumferenceyou find a flat bit of road, mark a chalk line in the tyre wall and the road (as one line). The push the car forward for
one rear wheel rotation - then mark the road next to the tyre wall mark and measure the length in inches. For a Spit on 60 profiles (185/60) it's about
65 inches.
Then apply this formula:
(60 x RPM / FR)*(RC / 63369)
Where RPM is the engine speed.
FR = Gear ratio * Diff ratio (for different gears)
RC = Rolling Circumference
The standard final ratios for your Herald are 1st = 15.42, 2nd = 8.88, 3rd = 5.74, 4th = 4.11.
So at 3,000rpm in second you should be doing 20.79mph - if your rolling C is 65 inches.
NiG
http://www.niginthecar.net