What is Dwell and what is "Adaptive Dwell "? 

Dwell is the measurement of the time an ignition coil charges before it creates a spark. 

This is normally expressed as a percentage of time in each engine cycle or a number of degrees in the rotation of the distributor. For example, in a 4 cylinder engine the distributor will rotate 360 degrees. Each cylinder will account for 90 degrees of the rotation. The dwell angle is normally set by adjusting the points gap, a large gap will mean points are closed for only a short time and will give a short dwell and a small gap will mean points are close for a long time giving a long dwell time. adjusting the points gap will alter the dwell time/angle .It has nothing to do with making a gap for the spark to jump.  If  the dwell angle is set at 45 degrees then this means the coil is charging for 45 degrees of rotation and at rest for the other 45 degrees of rotation. This can also be expressed as 50 % dwell time.

With traditional points and other electronic ignition systems the dwell time is fixed .

For example, in a system with a dwell angle set at 45 degrees ( 50%) the coil will charge the for 50% of the time regardless of engine speed. This means when the engine is turning slowly the coil is charging for a long period of time before it sparks and by the same token charging for a short time before it sparks at high engine speeds.

Does this matter ?

Well, yes it does.  Any coil has an optimum charging time, charge for too long and the coil reaches saturation (this is the point the coil cannot hold any more current ) and begins to produce excessive heat. While it is doing this it is also drawing around 2 - 4 amps of current putting unnecessary strain on the dynamo or alternator, this in turn takes engine power and uses unnecessary fuel .

At high engine speed too short a dwell time can mean the coil has insufficient time to charge to produce the perfect spark for maximum combustion. Setting traditional dwell time is always a compromise between low and high engine speeds.

The Stealth ignition system constantly adapts to engine speed keeping dwell time at the optimum 5 milliseconds to produce the best possible spark, keep coil temperatures down , fuel consumption low and power high .

Savings in fuel alone can be around 2% - 5 %  this unit can pay for itself in under 2000  miles 

The stealth kit will give improved motoring for years to come