Quote:
Originally Posted by mike the snake
This all sounds like a foreign language to me, but I seriously hope my tuner speaks in this tongue.
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It is not strictly necessary that your tuner understand this but it is helpful to all involved to understand what is going on within the cars engine and electronic control modules. Depending on your/your tuner's approach to engine tuning (meaning the hardware used, ECUTek, standalone, etc.) varying levels of overall knowledge are range from merely helpful to critically important.
What @
arghx7 is talking about is how the injectors are controlled. Different injectors require different circuitry and software to make them open and close properly and at the right time (which is critical given that each cylinder has ~60 combustion events per second at redline).
Each injector (port injection or direct injection) is basically an electronically controlled valve...well a really specialized electronic valve...that controls the flow of fuel into the intake port or combustion chamber. they are controlled through, no surprise, electrical signals delivered by the ECU.
There are multiple ways to control injectors, switching/pulsing grounds, current control, voltage control, etc. but for the sake of simplicity lets use Current control. You apply a certain voltage (usually 12V but up to 60V in the case of some direct injection injectors) usually via a connection to the battery to one pin of the injector. The other pin is controlled by the ECU. When you switch the ECU pin to ground you complete the circuit and allow for current flow. This current has to be controlled very closely to insure that you properly control the 'dynamics' or active behavior of the injector as it opens and closes to ensure it delivers the fuel charge you want in the way you want at the time you want. When you allow that current into the injector through switching the ECU pin, you run electrical power (VoltsxAmps) through a coil of wire that is rigidly attached to the outside of the injector body. That power creates a magnetic field. That magnetic field attracts the injector plunger or pintle that has a small magnetic section attached to the top pulling it upward. Pulling the plunger upward opens a channel allowing fuel to flow through the injector and mix with the air charge.
The challenge is that each brand of injector is designed differently (it's not random it's for good reasons for that vendor and design need) and requires different electrical behavior by the ecu ('algorithms'). To implement this at the OEM level is 'easy' because you are driving the design from the component level to the code level and because you have a large staff of engineers and vendors to help design the parts and supporting code. Some of this is publically released, some is proprietary. For our application as end-users/improvers it's a little different. If you do not have the info from the manufacturer of the parts then you are forced to reverse engineer it on your own...difficult at the most basic level, incredibly so if you need to also design new hardware to drive new injectors for a small market. This makes it so that on the GT86 software tuning of the ECU is possibly a better solution than going to an aftermarket standalone...at least for now, or I could be completely wrong on that. Direct injection is the future, but it has OEM level challenges to solve in my humble opinion.
Does your tuner need to know how to design that hardware? It depends on your tuning solution, if you are a standalone guinea pig I would demand far more verified trust in my tuner than just another software only tune.
TL;DR - It's basically a solenoid like you use on your lawn sprinklers, but way way more complicated.
TL;DR2 - would you expect the guy coding the next twitter to know how to build the individual circuits on Intel's new chip? Expertise is relative and important.