Direct injection LPG conversion is injecting liquid LPG directly into the combustion chamber. The LPG instantly vaporises, cooling the combustion chamber fuel-air mixture during the compression stroke, with further performance and emission improvements.
It is the automotive Holy Grail of a high performing vehicle with low cost fuelling…
LPG Conversion
In simple terms, this is the addition of a second fuel system including an LPG tank, intake manifold modifications, a new ECU and various fittings. These additions the vehicle to run on both fuels.
Types of Conversion
• Converter-and-mixer systems are the oldest style, dating back decades and still widely used.
The liquid fuel is converted into vapour and then mixed with air before going into the intake manifold.
• Vapour phase injection (VPI) uses a converter-and-mixer system, but the gas exits the converter under pressure and is injected into the intake manifold.
Electrically controlled injectors improve the metering of fuel to the engine, fuel economy and power, as well as reducing emissions.
This has been the most popular type LPG conversion in recent years.
• Liquid phase injection (LPI) systems inject liquid directly into the intake manifold, where it vaporises, not using a converter.
The fuel vaporising in the intake manifold cools and increases the density of the intake air, substantially increases power output, improves fuel economy and has lower emission, when compared to VPI systems.
• Liquid phase direct injection (LPDI) is a direct injection conversion and the most advanced conversion, injecting liquid LPG directly into the combustion chamber.
The LPG instantly vaporises, cooling the combustion chamber fuel-air mixture during the compression stroke, with further performance and emission improvements.
Best LPG Conversion System – Best LPG System
The best option is arguably the liquid phase direct injection (LPDI) system. LPDI systems are the latest generation in LPG conversion technology. The LPG conversion price for an LPDI LPG conversion would be at a premium, compared to other systems.
You get a substantial LPG fuel consumption savings (LPG average mileage) with an LPDI , combined with equal or better LPG engine conversion performance, LPG conversion MPG, great drive-ability and lower tailpipe emissions. It truly is the best conversion system (best LPG system).
Liquid Phase Injection (LPI) Systems – Liquid Injection
The system pumps LPG at high pressure from the LPG tank to the engine inlet manifold via a set of liquid LPG injectors. The injectors spray the liquid LPG into the intake manifold. The LPG immediately vapourises after being injected. This vapourisation process rapidly cools the surrounding air.
This cooling effect increases the density of the air-fuel mixture, ensuring power and torque are maintained and fewer CO2 emissions.
The effect is similar to intercooling on turbocharged cars.
An Electronic Control Unit (ECU) controls the various components of the liquid injection LPG conversion, including the injectors.
LPG injection signal optimises the flow and LPG injection timing. The ECU is calibrated to the specific LPG conversion vehicle and engine.
This is unlike conventional vapour systems.
Conventional conversion put the LPG through a device called a vapouriser before introducing it into the intake manifold.
This LPG vapour then goes into the intake manifold through either a mixer or an injector.
The result is a less dense air-fuel mixture, which means lower engine efficiency and output.
An old style vapour system can actually restrict vehicle performance, in comparison to liquid LPG conversion.
Direct Injection
Liquid phase direct injection (LPDI) is a direct injection conversion and is the most advanced, injecting liquid LPG directly into the combustion chamber.
The LPG instantly vaporises, cooling the combustion chamber fuel-air mixture during the compression stroke, with further performance and emission improvements.
The best LPG system is arguably the liquid phase direct injection (LPDI) – direct injection LPG conversion. LPDI systems are the latest generation in LPG gas conversion technology.
You get a substantial fuel savings with an LPDI, combined with equal or better engine performance, great drive-ability and lower tailpipe emissions.
Converting to Liquid LPG is a true Win-Win option.
Performance
A vehicle with a state-of-the-art liquid LPG conversion (gas conversion) produces at least the same amount of power when running on LPG, as compared with running on petrol. The dynamometer graph below shows the LPG conversion versus petrol performance comparison of a Holden Commodore VE 6.0L.
The liquid LPG conversion produced more power and torque than when running on petrol.
Reliability
Direct injection LPG conversion are so reliable that more than 1 million of them have been factory fitted by automobile manufacturers around the world.
Both Ford and HSV have chosen liquid LPG for their factory equipped LPG Autogas vehicles.
The manufacturers of these systems are so confident that they offer extended warranties on the liquid LPG systems.
Saving Money and the Environment
One of the biggest advantages of is the savings realised on fuel costs. Conversion will generally deliver a cost saving of between 50 to 65 cents per litre.
It is the safe, inexpensive way to run your car. Especially as the family budget seems to get more and more stretched!
This results in hundreds, if not thousands of dollars of savings every year depending on your vehicle usage.
Running an engine on LPG may also reduce maintenance costs.
LPG is a cleaner burning fuel than petrol, so engine life is not affected.
Environmental savings are also part of the equation.
It creates appreciably less carbon dioxide (CO2) than unleaded petrol.
CO2 is the primary greenhouse gas causing long term climate change.
Overall tailpipe emissions can be up to 15% cleaner than petrol.
Conversion Kits for Cars Price & Availability
Conversion kits for cars price varies based on the conversion type, with LPG converter-and-mixer conversion systems kits for cars being the lowest price range whilst LPG liquid phase direct injection (LPDI) conversion kits for cars would be the highest price range.
You can easily get online quotes or find online prices.
There are over 100 engineered Liquid LPG Kits available for domestic and imported cars available from a number of Australian suppliers.
There are also many specialist installers around the country who can install these kits on your car.
Maybe it’s time for you to consider getting the LPG conversion “Automotive Holy Grail”?