With regard to your request may I suggest that you try looking at an internet site http://geocities.com/93notch
If you follow the prompts - Cool Software I Wrote
you will be allowed to download a pre release version of his software and you will be able to see how it works.
The basic concept is that it measures acceleration times using spark pulses of a known engine format using parameters that you input advising it of vehicle weight and gearing etc.
I hope this helps