What is the difference between Venturi CNG kit and Sequential CNG kit?

One of the biggest questions asked within the automobile world is, “Is there a difference between Venturi CNG kits and Sequential CNG kits?” The simple answer to that question is yes, but you can find an elaborated comparison between the two kits below.

• While the Venturi kits don’t have sensors or the Electronic Control Unit, the Sequential kits come with all kinds of sensors and an ECU for better control.
• The Venturi CNG kits cannot control the amount of CNG flowing into the engine whereas the Sequential CNG kits come with the ECU to monitor the flow of gas into the engine.
• Venturi kits are extremely easy to install as they don’t require an ECU or computer to control the gas flow. On the other hand, Sequential kits are a little more complex to install.
• While Venturi CNG kits can be installed on any type of vehicle, Sequential CNG kits can only be installed on vehicles that have an Electronic Fuel-Injection system.

Advantages of a Venturi-type CNG kit

Affordability is probably the biggest advantage of a Venturi CNG kit along with the easy installation process. There are no complicated procedures or complex wiring required when installing a Venturi-type kit. Because the Venturi kits do not require an ECU to install, they can be setup quickly and by anyone.

Disadvantages of a Venturi-type CNG kit

The biggest disadvantage of using a Venturi CNG kit is its unpredictability. Because a Venturi kit cannot control the flow of CNG into the engine, it pushes a fixed amount directly into the engine’s intake system. This irregularity causes a lot of stalling and pickup loss as well. Also, because of this, the kit and engine need frequent tuning and cleaning – something that requires a certain amount of expertise.

Advantages of Sequential kits

There are a number of advantages of using Sequential CNG kits but the biggest advantage is that you get better performance and mileage from your vehicle through a more controlled CNG injection. However, there is usually about a 15 percent drop in performance on account of CNG having lower combustibility and higher octane rating when compared to petrol. This means that CNG performs a lot better on high-compression vehicles rather than regular ones.

Disadvantages of sequential kits

Although there are relatively no long-term disadvantages of using a Sequential CNG kit, it is the initial cost of the kit that can be considered a disadvantage. Some brands of Sequential kits can cost up to more than two times of a regular Venturi CNG kit. The installation process is another small disadvantage as it requires modification and drilling adjustments to the engine’s intake manifold.

Open-Loop and Closed-Loop Sequential systems

If you are in the market for a Sequential CNG kit, you have to decide whether you want an Open-Loop or a Closed-Loop system. The difference between the two is that one uses the oxygen sensor installed in the vehicle’s exhaust to collect feedback and deliver it to the ECU and the other does not. While they are both perfectly fine to use on supported vehicles, they do come with their own advantages and disadvantages.

Closed-Loop System

Closed-Loop system Sequential CNG kits are definitely the more eco-friendly option as they use the Lambda sensor or Oxygen sensor that is placed in the exhaust of a vehicle to collect feedback and pass it on to the ECU. This sensor checks whether the emissions from the exhaust are in the permissible limits. Using this feedback, the ECU controls the flow of CNG gas into the engine and prevents excessive pollution.