DTSi (Digital Twin Spark ignition) The digital CDI in the new Pulsar


The DTSi (Digital Twin Spark ignition) technology from Bajaj could potentially revolutionise motorcycling in the country. The company may well want to replicate the technology in its other engines as well. This technology, which is also being patented by Bajaj Auto, boosts the performance of the engine, while simultaneously cutting emissions.

The DTSi technology incorporates twin sparkplugs at either ends of the combustion chamber for faster and better combustion. Single sparkplug meant slower burning of the air-fuel mixture and sub-optimal combustion chamber characteristics. This is the heart of the new technology from Bajaj. But, its benefits are fully realised only after it is combined with a computerised direct ignition (CDI) system and new generation throttle response system. The path-breaking new DTSi engines utilize dual spark ignition for faster and better combustion. Conventional 2-wheeler engines use one spark plug at one end of the combustion chamber. The disadvantage of the single spark engine is that the flame front takes some time to reach the farthest portion of the combustion chamber. This leads to slower burning of the air-fuel mixture and creates limitations in optimizing the combustion chamber characteristics. Hence, 2 spark plugs at either ends of the combustion chamber help in faster and better combustion. This superior combustion offers both superior power and superior fuel efficiency besides of course reducing emissions. In fact, the DTSi engines are already 2005 compliant without the use of secondary emission controlling devices.

The digital CDI in the new Pulsar, which features an advanced eight-bit microprocessor handles the spark delivery. The programmed chip’s memory contains the optimum ignition timing for any given engine rpm, thereby squeezing out the best performance characteristics from the combustion chamber. Working together with the Throttle Responsive Ignition Control System (TRICS III) supposedly also delivers the optimum ignition timing for varying load conditions.

Bajaj has also developed a new third generation TRICS III to complement the new ignition system. The TRICS system controls the ignition based on throttle use. Depending on the needs of the motorcycle rider, whether for cruising or a burst of acceleration (such as for overtaking), the ignition requirements changes; especially useful in city riding conditions.

Based on the level of throttle opened, a magnetic field opens or closes the reed switch, which, in turn, is connected to the Digital CDI. The CDI then switches to the desired Ignition Advance Timing Maps (pre-programmed timing from the eight-bit processor). This helps the engine achieve an ideal ignition spark advance for every throttle opening and engine rpm level.

Current Relevance:-

This technology is used by Bajaj Auto Ltd. in Pulsar 150cc, 180cc, Discover 125cc.