Sequent Direct Injection is the new gaseous system  especially developed for the application on vehicles with petrol direct injection system. Based on the previous experience with Sequent Systems, SDI integrates new technical solutions for both hardware and software to assure the best integration on the most updated engines as direct injection ones. SDI interface software has been studied keeping the easiness characteristics but, at the same time, adding big potential as for the vehicle calibration.

March 2009 has brought more direct injection engines suitable for LPG conversion-

BRC and Zavoli offer lpg systems suitable for "Stratified Injection" petrol engines - Direct and FSI

More engine models are still due to be released, already in 2009 suitable engines include:- 

go back to HOME page

Phone us on 01903 715715 to confirm specific suitability. We need the exact Engine Code.

The system attenuates the petrol injection duty cycle by up to 95% and supplies vapour LPG to provide the required air / fuel mixture.

Prices are not much more than for normal systems, starting from £1740 + vat

Contacting us is the next step to "driving down the cost of your motoring"

"Volkswagen, BMW, Audi, Mitsubishi and Vauxhall have moved boundaries for petrol technology with FSI, GDI Direct injection units. ">

Automakers carve a new path to better fuel efficiency. Tech Talk Direct Injection - The Car Connection by Frank Bohanan

Every internal-combustion engine requires three things to function properly: fuel, oxygen and ignition. Of those three, the fuel delivery is the most difficult problem to solve, since spark plugs or ignitions can be located directly in the cylinder and ambient air provides the oxygen needed for combustion.

The problem of fuel delivery has led to the development of gasoline direct-injection technology (GDI). GDI solves a number of the problems of older "wet-flow" engines, while it also allows more air to enter the cylinder, thus improving volumetric efficiency and power. It eliminates the potential for fuel puddling and/or deposits on the intake valves, for example; it also helps ensure the amount of fuel delivered to each cylinder is consistent and optimal for each cylinder. These engines are better at complete combustion too, because their high fuel-supply pressures create smaller, more uniform fuel droplets. All told, GDI can increase fuel economy and reduce emission by five to 10 percent while boosting power by about the same amount.

Costly so far

So why hasn't this technology been brought out sooner? Cost, of course, is one issue but it is not the most significant one. Actually, the main problem is the sulphur level in U.S. fuel. Both Mitsubishi and Toyota have been selling vehicles with GDI engines in the Japanese market for years. They can't sell them here because the higher sulphur levels in U.S. fuels would cause the special catalytic converters these engines use to deteriorate too rapidly. Because GDI engines run lean most of the time, a special formulation of catalytic converter is needed to meet tailpipe emission standards. Unfortunately, this type of catalyst has a very low tolerance for sulphur.

A change is coming, however. In the near future, U.S. fuels will have lower sulphur levels by law, and that will surely help the spread of GDI technology. Some states such as California already require low-sulphur fuels and will thus probably see GDI vehicles even sooner. Too, automakers are looking for new catalyst materials that can tolerate more sulphur.

Besides the Mitsubishi and Toyota home-market efforts, many other automakers are working on GDI engines.

GM says it will produce a 4.3-liter "XV8" engine with direct-injection technology. This engine will feature a narrow 75-degree bank angle with two camshafts in the block and a three-valve-per-cylinder architecture. The XV8 will also have air-assisted fuel injection to help make sure the fuel is properly atomized as it is sprayed directly into the cylinders.

GM claims the engine will produce up to 300 hp in a package much smaller than a conventional V-8. GM's GDI technology also allows the engine to run at a relatively high 10.75:1 compression ratio while still using regular-grade gasoline, which should further enhance efficiency. The greater specific output, power density and efficiency due to the integration of GDI with other technologies will surely cause it to be applied to other GM engines.

The new V-12 engine in BMW's 2002 760i/760Li models is also a GDI engine but it does not run in a stratified charge/lean mode like the majority of other GDI engine designs. The BMW engine runs at a nominal air/fuel ratio of 14.7:1, and thus uses a conventional catalytic converter design, which is not as sensitive to the sulphur level of the fuel used. The engine uses BMW's "VALVETRONIC" and "bi-VANOS" technologies to control the valves to the point where pumping losses are reduced almost to the level claimed by electromagnetic valve systems, which completely eliminate the throttle butterfly. BMW's engine is an aluminium 60-degree, four-valve-per-cylinder design displacing 6.0-liter with claimed outputs of 408 hp and 442 lb-ft of torque. These figures dwarf the 326 hp and 361 lb-ft of torque generated by the current 5.4-liter engine in the 750 models, yet BMW claims fuel economy and emission performance will be substantially improved over the 5.4-liter engine.

GDI technology should ensure the internal combustion engine's ubiquity for quite some time, since it offers significant efficiency improvements without compromising overall performance. Direct-injection technology can even be adapted to use with alternate fuels such as hydrogen or natural gas to further reduce pollution. BMW, in fact, already has hydrogen-powered direct-injection engines under development for possible production.

Tech Talk Direct Injection - The Car Connection

VAG have said :- FSI direct injection system superior petrol engines

Volkswagen has moved boundaries for petrol technology with its FSI unit. FSI takes the TDI principal of directly injecting fuel into the combustion chamber at a very high pressure. Precise metering of both the quantity of fuel injected and the fuel spray pattern brings the petrol engine closer to the efficiency of today's reborn diesel engines.

The benefits of FSI are increased fuel efficiency, better performance and lower emissions, compared with similar-sized non-FSI engines. And yet FSI units produce more power than their equivalent predecessors.

The new Golf has several FSI engine options, including 1.6 FSI with 115PS. A 2.0-litre turbocharged FSI 200 PS engine powers the new Golf GTI.

FSI (Fuel Stratified Injection)

Performance and fuel efficiency combined

First developed for the racetrack, FSI technology from Volkswagen AG, enables better performance and a higher torque whilst simultaneously keeping fuel consumption low and reducing emissions.

How does it work?

Fuel Stratified Injection describes the stratified petrol direct injection attained by this engine. Supplied by a common-rail system, the fuel is injected into the combustion chamber at a pressure of 100 bar. The reduced consumption of the FSI engine is achieved by stratification in the low and medium speed ranges. One major achievement of this engine technology is the efficient exhaust treatment with a NOx catalytic converter for reducing the nitrogen oxides found in the exhaust gases.

The specific engine code is essential as this excerpt explains "Your car's engine is a direct injection petrol thus it would be not suited for LPG conversion. Direct injection engine, relies on petrol to cool the petrol injectors in the combustion chamber but running on LPG, this will not be the case and can lead to petrol injector damage.
However, the 1AZ engine used for African market is non-direct injection, so if you change the head and the ECU, in theory you can run it on LPG no problem without any damage. However, it is not economically viable to do so as the cost of doing so will probably wipe away the savings you will make by running on LPG.
I run my Avensis on LPG. I bought this one with 3S-FE engine, which is a non-direct injection engine mainly because I had LPG conversion in mind. The later model which have the same engine as your's (1AZ-FSE) looked attractive in many ways but went for the early model because of this.
But, the 1.8 variants (1ZZ-FE) is not a direct injection engine so this can still be converted. So as the 1.6 variants (3ZZ-FE) but on 1.6 will be under powered running on LPG so 1.8 is preferred."

Ring us with your engine code to discuss your requirements 01903 715715

Arun Autogas home