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@vvishwaskumar • 03 Jul, 2009
hello.. to all crazy brilliant engineers,,
can you simply diff b/t dtsi and mpfi engine tech.
@pramod.pal007 • 03 Jul, 2009 Re: hello... could you diff... b/t dtsi and mpfi

[FONT=Verdana, Arial, Helvetica, sans-serif]MPFI : mean multi point fuel injection system ie. in petrol engine for gaining more uniform Air Fuel blending fuel is injected at various point in the path of air. this tech is used in light weight car running on petrol. there is also milage improvement due to this.

but in case of DTSI(digital twin spark ignition) : the engine cylinder consist of two no of spark plug for proper combustion of charge.
@Rohan_sK • 03 Jul, 2009 Re: hello... could you diff... b/t dtsi and mpfi


The principle of operation is that, there is an additional SPARK PLUG introduced at the other end of the combustion chamber along with the usual spark plug with the the traditional placement at the top centre.

The idea was introduced considering the SLOWER Flame Propogation with only one Spark Plug as in traditional engine design.

Also due to the rectangular shape of the Combustion Chamber the Flame could not reach all the sides and corners regions of the Combustion Chamber, thus leaving some amount of the A/F mixture UNBURNT.

Both the above points were a drawback resulting in :

Slower and Incomplete burnig of the A/F mixture thus Producing LESSER POWER, LOWER FUEL EFFICIENCY and HIGHER HC EMISSIONS.

By introducing the DTSI, due to Two Spark Plugs at two opposite ends of the Combustion chamber, there is:

Faster and More Precise Flame Propogation and,

Better reach of the Flame covering more chamber space resulting in Greater amount of mixture burned in a more even manner.

There is also Swirl Induction incorporated at times for bettermixing inside the combustion Chamber and give better Burning of the fuel.

Both these Improvisations lead to Higher Fuel Efficiency and Higher Power and Torque Developed.
This considerably Improves the Engine Performance, than the traditional FI systems.

The Engine Power and Torque is believed to improve by nearly 8% by using DTSI

Also the DTSI is combined with the COMPUTERISED DIRECT IGNITION or CDI which is an eight bit microprocessor chip with preprogrammed maps of Ignition Timings for various engine rpms and engine loads.
The CDI works along with the THROTTLE RESPONSIVE IGNITION CONTROL SYSTEM. This TRICS controls the Ignition based upon the Amount of Throttle Opening.
Thus when the rider Accelerates suddenly or goes on a smooth uniform drive mode, the Ignition requirement varies acccordingly.

Hence the Throttle openig also changes, this is sensed by the TRICS which accordingly opens and closes the Reed Switch operated magnetically. This TRICS is connected to the CDI which inturn controls the IGNITION SPARK ADVANCE AND TIMING thus giving a much efficient SPARK ADVANCE for every engine rpm and load conditions.

This eventually increases the Engine Performance and Fuel Efficiency of the vehicle and reduces the HC Emissions.


In this there is atleast ONE INDIVIDUAL FUEL INJECTION NOZZLE/PORT for EVERY INDIVIDUAL CYLINDER of the Engine as oppposed to the ONE CENTRAL FUEL PORT in the traditional Engine design.

The basic idea is to provide better ratio of A/F mixture in every cylinder nearing the Stichiometric Value of 14.7 : 1 as far as possible for all various speeds (rpm) and acceleration demands.This was not so much achievable with the single central fuel port system.

This system allows to have a desired A/F ratio for demand condition, thus almost elimnating the A/F distribution issues.

The MPFI includes intake runner length adjustments, MAF ( Mass Air Flow) sensors, coupled to the ECM ( Electronic Control Module ).

The Longer intake runners are for Low Torque Demand in normal road driving, amd Shrter Intake runner for Sudden High Rpms and Acceleration requirements.

The MAF sensors are situated between the Air Filter and the Throttle body in the Intake Manifold. This sensor accurately measures the Air Flow Rates into the engine ( which is an indication of the engine rpm) and sends the feedback to the ECM which inturn does the PROPER FUEL METERING .

Thus a correct A/F ratio can be achieved in each cylinder. This inturn assures
a better fuel Efficiency,
greater power output for same mixture ratio,
a much better control over the A/F ratio as per te instanteneous speed demand.
Overall better performance.
@Kaustubh Katdare • 03 Jul, 2009
hello.. to all crazy brilliant engineers,,
can you simply diff b/t dtsi and mpfi engine tech.
PS: Refrain from using SMS text in your posts and provide a redable title that gives idea of the post contents.
@gohm • 04 Jul, 2009 Good explanation Rohan_sk.
@Vivek Rajkumar • 08 Jul, 2010 dtsi is related with ignition system and mpfi is related with fuel supply system

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