IPE is an abbreviation for; Injector Period Expander and is the term that describes my circuits here, which is intended to convert electronically controlled fuel injection system adapted for high-energy fuels to also run on low-energy fuels. Thus, so a modified normal petrol car basically becomes a flex-fuel car.
G-series is the latest developed structures and were completed in the spring 2010. The only earlier designs that live further are IPE-S - in a refurbished condition. IPE-S is a very simple design and has bad proportionality/linearity. It is also far too quick at the start up which makes the car somewhat difficult to start when the engine is hot. A cold start choke is missing for sequential systems but is now available for common multi-point systems. Despite the drawbacks of IPE-S am I still impressed by how well this simple circuit works... IPE-S is designed to work with induction-voltage transients that derived from the fuel injectors.
IPE-GP is tested in multi-point systems and has everything but is quite easy to build - if one skips the FFG circuit? IPE-GP can be equipped with automatic choke and fuel enrichment.
IPE-GS and IPE-GP (g-series) is significantly smarter than the previous now obsolete IPEFF and works without any external power source. The G-series control one or more fuel injectors via a single cable, which also supplies the unit's internal power requirements. However, one must have a particular interest in electronics, own some knowledge and resources to built them. IPE-GS can control the fuel system automatically, but this requires at least two additional modules and involving an insertion of the lambda probe.
A new electronic device CSD seems be able to replace all modules regarding choke/enrichment!
The designs are based on analogue mixed with digital technology - the best of both worlds. I think it is most appropriate here as we are now running with public information that is accessible to all. Sure we can do the same with a microprocessor, but this will require that one can dispose of extra resources in the form of software and hardware.
All the electronics projects about IPE can be studied in both Swedish and English.
At the bottom you find a chart that provides information of the linearity over different models.