Quote:
|
Originally Posted by 2.2 Straight six
usually auto are 3-speed, or they are here at least. that increases time to reach a certian speed because it has longer/taller gears.
|
Its been a while since I saw a 3sp Auto.
Most went 4 speed in the 80 (incl OD).
5sp became common in the late 90s, and now there seems to be no Limit, I believe both BMW and Mercedes have a 7sp Auto in some high end cars.
The vast majority of automatics relly on a Torque Converter, which makes a fluid connection between the engine and the wheels, it works really well, except you lose response to changes in engine speed as the fluid in the TC has to be spun up to speed and that in turn has to spin the gearbox up to speed.
Works well on a big lazy V8 pushing around a family car, dosn't work so well on a high end sports car that your trying to balance on the throttle mid corner.
There are ways around the problem, like useing a Lock Up TC that locks the torque converter to the engine, but they still unlock at idle, or when stopped, or other times when its still nice to have instant throttle response. Or, the gear box modified in such away it makes hard fast changes with a high stall speed on TC, ok in a race car, not fun on the road.