TSI, TSFI,FSI, CGI Engines Useless in India ?

Turbocharged Stratified Injection (TSI) In Skoda Turbo Fuel Stratified Injection (TFSI) In Audi Fuel Stratified Injection (FSI) In Volkswagen Stratified Charged Gasoline Injection (CGI) In Mercedes Q.Now what is this stratified fuel injection? A.It is a one of the mode in which these engines run. Fuel is injected directly into the cylinder. The other mode is homogeneous mode.(On which our normal cars run ) Q.What's so special about this mode? A. 1) The engine runs on leaner AFR's (upto Lambda 3.0). Lambda 1.0 = 14.7 : 1 i.e stoichiometric air fuel ratio 2) The fuel is injected at the end of compression stroke (like common rail diesels) 3) The butterfly/throttle valve is kept full open & injection of fuel is controlled via accelerator pedal (like common raid diesels) Q.Draw backs of lean air fuel ratios? Attachment 845659 1) Combustion of lean AFR's is doubtful To overcome this drawback they have made the Air Fuel Mixture inhomogeneous. The air fuel mixture near spark plug is rich (Resulting is guaranteed combustion) The air fuel mixture away from spark plug is lean (resulting in complete burning of fuel The air fuel mixture near cylinder walls is leanest (resulting in a thermal insulation to the cylinder liners) 2) High Heat produced results in high engine temps & makes the inert gases react To overcome this drawback the EGR has been reworked. Air Intake Charge consists of 30% exhaust gas which helps in lowering the combustion temps & keeping the inert gases intact. 3) Higher emission of harmful gases especially Nitrogen oxide New exhaust system has been designed with a additional Nitrogen Oxide Storage Catalytic Converter behind the normal catalytic converter which comes on conventional cars. This new catcon stores the nitrogen oxide & nullifies it slowly. When it exceeds the capacity of holding more nitrogen oxide it tells the ECU & the cars running mode is shifted from stratified to homogeneous. The exhaust gases coming from the engine during homogeneous mode react with this stored nitrogen oxide & go out into air as nontoxic gases. This way the catcon is flushed out & the car can go back to stratified charge mode if required. This catcon works in high & narrow temperature band. So to reach the desired temperature quickly & maintain it in the narrow band working temps various sensors & pipes are a part of this exhaust system. Q.What is Homogeneous mode? Attachment 845593 A.This is the normal mode in which air & fuel is sucked in together during suction stroke then compressed & ignited. The air fuel mixture in this mode is homogeneous like on our normal cars. The air fuel mixture is kept rich since engine is switched to this mode on sudden throttle & high power delivery modes only. Q.Selection of modes based on what? A.Selection between Stratified Mode (Economy mode) & Homogeneous Mode (power mode) is dependent on the engine load & throttle position. Low speed, low loads – stratified mode. Medium speed, low load – stratified mode. High speed, high load – Homogeneous mode. Q.Why are these stratified engines useless in India ? A.They need min 95 Ron fuel. Anything less then that has high sulphur content which damages the new nitrogen oxide storage catcon. The result is high nitrogen oxide going into atmosphere which the sensor senses & tells the car to run on homogeneous mode thinking the catcon is full and needs to be flushed. So in short the car never runs on stratified charge mode & you don't get the fuel economy you should be getting. All you get is just a little more power compared to normal fuel injected petrol engines. lol: This is just a small part of my college presentation copy pasted.There are many other changes such as head design (swirl ports,charge ports),fuel system,etc in startified charged engines. If any specific question let me know will try my best to answer.:) Attached Images

URL: