ECU tuning is a catch all term these days, and as the name says, it’s tuning the ECU (wow no shit Sherlock)
First let’s define the word tuning.
Tuning is not tune up, but tune up is a form of tuning. Confused?
Tuning simply means making adjustments. The first image that comes to most people’s mind is someone adjusting the strings on a guitar
Or a piano being tuned.
And that’s where the word comes from, to adjust the instrument so that it performs optimally, and in the case of musical instruments, produce the correct tune
Tuning cars is principle is the same, making adjustments for peak performance, which is optimum horsepower and torque.
Tune-up is the adjusting the carburetor and the distributor back in the old days, for optimal performance, and this is a form of tuning.
With cars now being computers with wheels, all adjustments are now made with, well, a computer. And all computers are run by software which is a set of instructions that tell the engine what do, how much fuel to give, when to first the sparkplug, when and how much to open the wastegate etc etc
But first you must be able to talk to your cars ECU and be able to make the changes and adjustments you want. For that there are two pieces of software for the job. A flasher and an editor.
First the flasher, this is essential a file uploader and downloader. You plug an OBD to usb cable like this from Tactrix
So that you can download the physical file that resides inside the chip of the ECU. And this is a small file, 1-2mb in size, smaller than an mp3 song.
Different manufacturers have different protocols for how you can download the contents, let’s call them locks. The flashing software is basically a set of keys that allow you to open the different ecus of different cars to be able to get the file, as well as put the file back and lock the door.
But once you have the file, which is almost always binary format, is next to useless as you can just open it with MS word and start editing. You’ll need another software called an editor
This interprets the file which is zeros and ones (hence binary) into something humans can see and understand. All tuning software in the world looks like this, a bunch of tables and excel sheets, with values in the table that you can adjust and change.
The act of changing and adjusting these values is tuning, after which you save the changes and then use the flasher to upload the edited file back into the cars Ecu.
But how do you know what numbers to change and by how much?
Well that’s where having a Dynamometer is essential. A Dyno is basically a very expensive glorified treadmill for the car, it does one thing and one thing only, give you horsepower and torque figures. That’s it. A Dyno doesn’t do any tuning, any adjusting or manipulation. It’s a ruler for the car.
Having a Dyno let’s us, the tuner, see if the adjustments we have made resulted in more, or less, power. Tuning at its very heart is trial and error. This value doesn’t work, maybe we make less, and make this value more until we get the desired result.
As for which excel tables to adjust and what they do, well that’s what you’re paying money for, the knowledge and experience of the person knowing what to adjust and by how much