Oke guys, let me just briefly explain about the article in the dutch electronics magazine, and some experience i have with ECU's/CPU's and programming.
ECU's are just very simple stand-alone computers. The early ones were nothing more then a Z80(processor, often a 80C39) with a Eprom (UV-eraisable) next to it. The so well known 'chip'.
On the board there was a transistor for controlling the injector (single point), an analog to digital converter, and a 12V to 5V powersupply.
I repaired those for car dealers, and they where more then happy to pay up to USD250 for a repair. Keep in mind that the parts on the ECU costed me USD20, thats for ALL the parts including CPU/Eprom/buffers/ADC's. And yes, thats what the ECU's from todays cars cost in parts as well (maybe a couple of tenners more). Funny to pay hundreds, sometime even thousands of dollars for a new one.
Don't expect militairy standards parts inside (MILSPEC). They have used the cheapest parts on the market.
The present ECU's look a bit more challenging inside, but the whole thing is still based on a CPU and Eprom (sometimes inside the CPU) and ADC converters.
In the beginning all IC's where having there names on, today most parts have a customized number on, but are still the same parts as then. It stops people like me repairing them.....
It's mainly the programming which has evolved over time.
Now there is where the mistery is, in the programming.
A CPU can be programmed in different language's, such as C, Pascal, Forth etc. The best choice would be assembly, because it is very fast executing, but very hard to programm (i love assembly!).
This program is stored in the Eprom 'chip', or in the CPU and the Eprom.
This program has to be altered for making different engine characteristics.
This is where the cowboys and proffesionals come in.
The following steps should be taken for a proffesional change:
- Reading the program from the Eprom and/or CPU into the a assembler on a PC.
- Analyzing the program, which will cost a lot of time. Especially if these programs are a compiled C program.
- Defining new parameters.
- Altering the program.
- Reprogram the CPU and/or Eprom.
- Test the new ECU on a dyno.
- feedback.
- Alter parameters.
The engineers who done the initial program, are not stupid (duh).
The program is written so the engine will perform at its maximum in any enviremont, which can alter, such as altitude, moisture in the air, temperature (!!!!) etc.
The disadvantage of this all, is that the program is standard for all (NSX) engines, so none of the engines comming of the factory will have the ultimate ECU for it. This is where any gains, if any, can be made.
Where it goes wrong:
There are a lot of 'tuners' who would just read the data from the Eprom, and put an 'offset' onto it.
They just fiddle about with the offset, until the engine runs smooth, and there seems to be a difference.
What really happens, is that all prarameters of the engine are getting altered, in an uncontrolled way.
Apparently, this sort of 'chip-tunning' happens a lot.
Funny to see that a european company has 'chips' for the NSX, especially here in Holland, where only a dozen or so got sold over the last 11 years.
I know that most of these 'chips' are comming from the UK, but then, there are no parkinglots full of NSX's over there either.
The conditions for a good chip-tuning:
- Tuner will 'make' a chip for youre car on a dyno.
- Tuner will warranty any engine damage if caused by the chip (sure).
- Tuner will give you names and numbers off people who have there car done by them.
Remeber that this won't be done in a hour or so. So a good one might ask you to leave youre car for a couple of days.
Especialy a NSX will be very timeconsumming. Think about VTEC and VVIS, hell of a job if you ask me.
So howcome there are so many 'chip-tuners' who don't know what there doing ? Well, the answer is simple, looking at the list above, it would point out that a electronic tuner would need knowledge off:
- Micro electronics on a medium to high level.
- SMD soldering skills, on a high level. The PCB's ECU's are made off are very, very cheap, so soldering these is a challenge alone.
- extensive knowledge of micro-processors, and digital micro electronics.
- Knowledge of programming in assembly, if you know what sort of assembly you just read out of the ECU (remember there is no CPU number on them).
Next to the above skills (micro electronics students with experience only???), you will need very extensive knowledge on engine parameters!
Normally, these two don't go together very well.
Sorry for poor english,
Dutchy