2 stage injectors on turbo engine, LPG + petrol

[mr_g]

I get an idea to put LPG injectors as a first stage injection, and petrol injectors as second stage injectors above 0.3bar... VEMS already support 2 stage injectors, but, LPG doesn't have constant pressure, and it can't be used when engine cold...

Better solution would be 2 stage injectors but first stage (LPG) totally cut, when MAP rises above let's say 0.3bar...

In what phase those developer guys are related to bifuel on turbo engines?

[rob@vems.co.uk]

Its difficult to say where people are on this development because most dont report anything until they have some data or proved a theory.

The best way to approach this would be to start to figure out what Pulsewidths you will need for the different injectors and to try and simulate this with a VEMS on a test bench.

Swapping injectors while an engine is running is a fearfully complex task and should really be exhaustively simulated before attempting to run an engine.

[mr_g]

injectors (first and second stage) are close one to the other.

What is a test bench?

[rob@vems.co.uk]

Switching one to another will cause drivablility problems around the switching point, there needs to be a strategy to phase from one bank to the other.

A test bench is a setup that will allow you to run tests on your hardware without it being in the car.  For mine I have a set of Econoseal plugs with grounds, power supply and outputs connected to a set of LEDs. TPS, IAT sensors and a wideband connector so that I can calibrate the sensors.

For simulation of crank triggers I use the signalgen app (in the Tools directory of the MegaTune releases) to create trigger patterns and the sound card outputs connected to the trigger inputs.  For MAP simulation you'd be best to use a variable resistor connected to +5v and ground feeding the wiper to the MAP signal.

[mr_g]

Nice.