MoTeC Global Forum

Hi folks,

We are a formula student team and are currently running a M800 ECU with two injectors per cylinder at different distances on a Yamaha R6 engine. We use two injectors to improve mixture, since we are running with E85.
Now we want to improve mixture even further and consider the concept of a high pressure port fuel injection.
Which components do I need to run high pressure injection, apart of the high pressure injectors and pumps? Is the M800 capable of running high pressure injection? If not, I found the M1xx-Series which is capable of direct injection. Does this mean that the system is capable of high pressure injection? Is the software comparable to the M800 software and analysis software?
Thanks a lot.
Greetings

When you talk about high pressure injection, what pressures are you talking about?

The DI systems run over 5mPa at idle, and go to around 12~15mPa under load. This can only be done by using a mechanical fuel pump that is typically driven off of the camshaft, either a rotary swage pump or a piston pump. The injectors are also driven in a different manner to those used in port injection systems, with special drivers needed to control the energy levels needed. It is the control of these systems, and the calculations behind it that makes the M1 series capable of running DI engines, and the Hundreds not. You need to use either the M142 or M182 to drive DI engines, as they are setup to control Solenoid DI injectors and the pumps.

To run DI engines, you need as a minimum a cylinder head that has been machined to accommodate the DI injectors and has a mount for the pump, you also need a camshaft designed and ground to run the pump. You may also need to change the design of the pistons to accommodate the injection of the fuel into the cylinder so that you get a proper swirl and blend in the squish area.

With port injection, usually around 600kPa differential fuel pressure is the top end of the scale for the injectors, above this you start to have control issues with the injectors not being able to be opened in a consistent manner due to the pressure that they are working against, as well as loosing resolution at smaller opening times as the injectors cannot open for a short enough period.

The tune software for the M1 series ECU's is totally different to the Hundred series, but they both use i2 for data analysis. You can download the M1 Tune software from https://moteconline.motec.com.au/Home/Downloads and load a base package to see how everything works, and there is also M1 Build that, in conjunction with a Development licence, allows for the development of custom firmware to run your engine.

Hello Stephen,

Thank you for your detailed explanation. That helped a lot.
Is it possible to connect two injectors in parallel (electrically) to one injector output of the M800 to drive them equally, as long as the total impedance is above 12 Ohm or the total current does not exceed 6 A? A use case is for example one injector per intake valve.

Greetings

Hi,

It is possible to batch injectors together as described, as long as they are Hi Impedance.