have searched the net and am not satisfied with any answer I have found to calculate the following:- Here is an example just for reference. Suppose I can accelerate my car from 0-100km/h in 10s. That means my acceleration=2.78m/s/s. Say at 7000Rpm it hits 100km/h in the first gear itself. Now, while I am still very much in gear I lift my leg off the accelerator (no clutch is pressed). It will begin to decelerate, till it hits 1000Rpm and keeps that constant rolling pace of 14km/h. I want to find out the rate at which deceleration takes place? I want you to keep drag/aerodynamics/friction (air & road) etc etc as any normal accepted values, no preciseness required over there. Just need an approximate idea of how I could calculate the rate at which speed drops.
It's easy to measure this by bringing your car to top speed, putting it into idle, and then watching the speed over time as the car decelerates. Here are some simple instructions, which will yield your deceleration rate at any given speed. Then, choose at what speeds you'll shift and how long it will take, and you'll have your answers.